subject:"Re\: RFC\: EBBR specification update"




On 10/03/2020 22:19, Heinrich Schuchardt wrote:

On 3/10/20 9:45 PM, Francois Ozog wrote:

Le mar. 10 mars 2020 à 21:15, Heinrich Schuchardt  a

0.2 - normative text
The normative section shall be stated clearly: is " 1.2. Guiding
Principles" normative?

IETF and ETSI have different language conventions to express
absolutely mandated and various levels of optionality. This spec may
be red by Telecom people or Linux people. Their interpretation may be
erroneous on words such as "shall" (ETSI "SHALL" = "IETF "MUST"). The
language need to be explicit.


A reference to RFC 2119 should be added to the EBBR.


https://github.com/ARM-software/ebbr/issues/46

g.
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Re: RFC: EBBR specification update


Just a general note on this entire thread; if there are specific things
you want to clarify or add to EBBR, it would be helpful to add them as
issues in GitHub here:

https://github.com/ARM-software/ebbr/issues

g.

On 10/03/2020 20:14, Heinrich Schuchardt wrote:

On 3/10/20 5:02 PM, Francois Ozog wrote:

Hi,

Following implementation (or work towards) of EBBR 1.0 + UEFI Secure
boot + UEFI update capsule we learnt a lot.

Here are some topics that may need some clarification on the EBBR
specs and It looks timely to start working on EBBR evolution.

0.1 - EBBR goal
May be a reassessment on the "for what" the specification is built.


EBBR 1.0 is quite vague about this point.

Implementing the requirements of version 1.0 was enough to allow systems
to be booted in a common way. Secure boot is not supported by what is
required.



Following all the discussions with prominent industry players, I start
to think that limiting the constraints to be EBBR compliant may become
counter productive. There will be both EBBR non compliant and EBBR
compliant systems. This is inevitable. But EBBR exist for a number of
use cases in a number of markets. The value of EBBR is consistent
behavior across those.

Maximising number of EBBR compliant systems without stating use case
parameters ( "why" and "for what") may not be the best goal.

Out of things to be more explicit are supported secure boot flows
(with/without shim+grub or direct). Some vendors require shim+grub
while industry players want the exact opposite: nothing but UEFI. This
drivers a number of requirements in terms of UEFI protocols needed


Shim and GRUB are optional tools which operating systems like BSD, Linux
or Windows do not need for booting. I think the EBBR should be operating
system agnostic.

This does not deny the usefulness of some of these tools. My personal
favorite is booting via U-Boot -> iPXE -> GRUB -> Linux from an iSCSI
drive ;)



0.2 - normative text
The normative section shall be stated clearly: is " 1.2. Guiding
Principles" normative?

IETF and ETSI have different language conventions to express
absolutely mandated and various levels of optionality. This spec may
be red by Telecom people or Linux people. Their interpretation may be
erroneous on words such as "shall" (ETSI "SHALL" = "IETF "MUST"). The
language need to be explicit.


A reference to RFC 2119 should be added to the EBBR.



I - protective offsets
EBBR 1.0 states in "4.1. Partitioning of Shared Storage" that
"Automatic partitioning tools (e.g. an OS installer) must not create
partitions within the first 1MiB of storage, or delete, move, or
modify protective partition entries."

StandaloneMM is 2.5MB by itself with U-Boot being over 1MB without the
variable rework done and update capsules. 4MB seems the minimum. 8MB
to get margin and 16MB for A/B scheme.

EBBR same paragraph also states:
"Automatic partitioning tools (e.g. an OS installer) must not create
partitions within the first 1MiB of storage, or delete, move, or
modify protective partition entries. Manual partitioning tools should
provide warnings when modifying protective partitions or creating
partitions within the first 1MiB."

is it expected that Linaro upstreams changes in installation tools,
partition tools to conform to this (with updated to be agreed
minimum)?


Obviously the minimum required space depends on the firmware and the
maximum depends on the hardware (some devices like routers simply only
have 16MiB flash for firmware and operating system in total).

Shouldn't the firmware have a way to tell the OS how much space it wants
instead of prescribing a fixed quantity?



II - identifying partitions
Having two EFI partitions defined with EFI_GUID need a precise
behaviour defined: boot with first or boot with second.


This is only relevant when relying on the \EFI\BOOT directory. If
Boot variables are defined, these specify the relevant partition.



Shall we have a EFI_GUID_ALT defined for A/B partition schemes?
If not, the BootXXX variables should be used as selector?
We lean towards BootXXX variables and not defining a new GUID. But
this would mean explicit behavior to be stated in case of lack of
BootXXX.

I think GPT volume mirroring should be used in conjunction with A/B:
A/B to recover version failures with current hardware, surrounding
software; mirroring to protect against storage failures.

Is there any recommendation on mirrored EFI volumes handling ?


Isn't the availability of Boot variables enough?



III - 32 bits
are there any 32 bits specific considerations to be added?


The only thing 32bit specific that comes to my mind is clearing
architecture specific caches as defined in the UEFI spec.

For RISC-V there is a development ongoing for communicating the boot
hart ID form the firmware to the operating system.



IV - UEFI_RNG_PROTOCOL
Following my view in 0) I think this shall be made mandatory


EBBR v1.0 has as design goal: 'Design for common embedded target'.
"Generally anything

Re: RFC: EBBR specification update

On 12/03/2020 04:58, Sumit Garg wrote:

On Thu, 12 Mar 2020 at 03:11, Francois Ozog wrote:

Le mer. 11 mars 2020 à 22:22, Heinrich Schuchardt a
écrit :

On 3/11/20 12:10 PM, Daniel Thompson wrote:

On Tue, Mar 10, 2020 at 06:34:35PM +0100, Francois Ozog wrote:

On Tue, 10 Mar 2020 at 18:19, Daniel Thompson <

daniel.thomp...@linaro.org>

wrote:

On Tue, Mar 10, 2020 at 05:02:27PM +0100, Francois Ozog wrote:

0.1 - EBBR goal
May be a reassessment on the "for what" the specification is built.

Maximising number of EBBR compliant systems without stating use case
parameters ( "why" and "for what") may not be the best goal.

We have resisted levels in EBBR until now but this might be where might
have a need for them.

Put another way I agree that getting explicit about mandatory features
for secure boot flows is useful.

However I also think that is remains valuable to define best practice
for how firmware and OS interact on systems that have not implemented
secure boot.

It's all about the target use:

1) industrial (manufacturing, automotive, robotics, medical...)

components

2) telecom edge
3) 96boards
4) developer desktop
5) server

As I just consider 1 and 2, I have no case without secure boot...
Now the dev platform can come without the secureboot active and
SElinx deactivated
In what context you think this is usefull?

I would like it to be possible for dev boards and SoMs whose SoCs do not
have a built-in root of trust to have some basic level of EBBR
compliance.

I don't like to optics of saying "this standard cannot possibly apply to
a Raspberry Pi"[1]. Taking the RPi Zero or CM3 as examples[2], I can't

see any

value added by secure boot since the root-of-trust would have to start
on the same media as the operating system anyway.

There is a TPMv2 module available for Raspberries.

https://buyzero.de/products/letstrust-hardware-tpm-trusted-platform-module?variant=33890452626

Would we be able to use this as root of trust?

EBBR should account for RPi and similar because it is a very convenient
development platform, but there are very few security requirements that
can be guaranteed.

What do you think of a security addendum or checklist that goes
alongside EBBR to detail what is required to make the platform actually
secure? EBBR proper can specify the functional interfaces, but security
certification is outside EBBR scope.

g.
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Re: RFC: EBBR specification update




On 11/03/2020 16:42, Daniel Thompson wrote:

On Wed, Mar 11, 2020 at 01:42:36PM +0100, Francois Ozog wrote:

On Wed, 11 Mar 2020 at 12:45, Daniel Thompson 
wrote:


On Wed, Mar 11, 2020 at 11:20:17AM +0100, Francois Ozog wrote:

On Wed, 11 Mar 2020 at 07:48, Heinrich Schuchardt 

wrote:

On 3/11/20 12:04 AM, Heinrich Schuchardt wrote:
In the expert mode of gdisk there is command 'j' for moving the GPT
Partition Entry Array to an arbitrary sector. This will protect the

area

between the GPT header and the GPT Partition Entry Array from being

used

for a partition. The same can be done with parameter -j of sgdisk.

Furthermore gdisk supports creating a hybrid MBR. This allow to have
GUID partition table and a MBR partion table at the same time where the
MBR partition table mirrors up to three GPT partitions and the fourth
MBR partition is used to protect the GUID partition table.

So requiring GPT and having boards only supporting booting from an MBR
partition (like the Raspberry) seems not to be exclusive.



That sounds like a great solution!


The last time we discussed this there was *very* strong opposition
during meetings to hybrid partitioning and IIRC language was added to
the spec to prohibit it.

Hybrid partitioning is a problem because it imposes to difficult to meet
constraints on partitioning tools provided by the operating system.

In other words if we permit hybrid partitioning in order that boot code
can find the firmware then the operating system would inherit a duty to
not to screw up the firmware loading when it modifies the partition
tables. It is hard to express how the OS should go about that.

Hence the current approach where we accept that MBR partitioning
offers an inferior feature set to GPT.


Yes. I think a hybrid MBR should not be adopted. It is not allowed by 
the UEFI spec's definition of GPT partitioning. Plus there isn't much 
point. If there is no way for an existing platform to use GPT, then fall 
back to MBR and be done with it so that there isn't any ambiguity on how 
the disk is partitioned. Hybrid MBRs have caused problems in the past.



We have the following cases:

- FW compatible with GPT  (I mean firmware can be searched based on
GUID partition)
Ok

- FW that uses offsets and can be positioned at LBA >= 33
Ok
Need to define a protective partition >>
- FW that uses offsets and can be positioned such that space between LBA-2
and LBA-33 is used.
Ok in theory as the header states where the partition entries location is
specified in a GPT_HEADER "Starting LBA of array of partition entries".
Linux kernel properly loads the partition entries if we push them after
16MB.

read_lba (state,
le64_to_cpu 
(gpt->partition_entry_lba)

But I bet 2 is hardcoded in many tools...


Agree... but that's "just bugs" and I suspect we could get >90% test
coverage for Linux systems just by checking util-linux (and the kernel
itself). Maybe for extra style points also check on of the BSDs.


It is worth stepping back from the details to take a look at the intent. 
The purpose of this entire section of EBBR is to describe how firmware 
and the OS can co-exist on the same media device. In broad strokes it 
means if firmware is stored on the block device, then the OS must 
constrain how it uses the device.


On platforms with separate firmware storage (e.g., SPI flash or UFS boot 
partitions) this isn't an issue. The OS can blow away everything on the 
disk and recreate it.


But when it is an issue, the rules need to lay down what regions 
(offsets, partitions, or file paths) firmware is allowed to own and what 
the OS is and is not allowed to do. e.g., the OS is allowed to erase and 
recreate the OS partitions, but it is not allowed to write a blank GPT 
or erase the system partition.


I think the EBBR spec should focus on defining exactly what restrictions 
on the OS are, and how the restrictions are communicated. Then OS 
vendors have a fighting chance of supporting the restricted platforms well.


Ultimately though this is a guide and the OS could choose to ignore the 
restrictions... in which case it gets to keep the unbootable brick when 
it does. :-)



- FW that supposes LBA-1 (macchiatobin the firmware blob that contain TF-A
must be here)
In theory OK as Linux will detect bad signature and use the alternate GPT


In the current spec this case isn't materially different to firmware
whose boot ROM parses the MBR to load extra code (which wasn't listed
above). In both cases the system would be expected to adopt MBR and
create protective partitions for the firmware (and accept that the
protective partition is vulnerable to damage by auto-partitioning
installers).

Having said is this really relevant for MacchiatoBin? Why put EBBR
firmware onto shared media? I thought MacchiatoBin could boot from the
4MB SPI NOR.


Yes! This is the preferred solution. All this GPT/MBR r

Re: RFC: EBBR specification update

2020-03-27 Thread François Ozog

+Poonam Aggrwal 

On Thu, 19 Mar 2020 at 17:42, Heinrich Schuchardt 
wrote:

> On 3/19/20 1:21 PM, Grant Likely wrote:
> >
> >
> > On 19/03/2020 12:03, Heinrich Schuchardt wrote:
> >> On 3/19/20 12:31 PM, François Ozog wrote:
> >
> >>>
> >>> I haven't followed the technical discussion. following is the original
> >>> intent behind the changes requested for variable handling:
> >>> - runtime services are not the best things and even EDK2 are probably
> >>> moving away from this (Grant told us that at a design sprint a year
> ago)
> >>
> >> Operating systems like Windows rely on setting Boot* variables. Do you
> >> plan to break them?
> >
> > If Windows is the goal, then SBSA/SBBR/ServerReady is the interface. I
> > don't think it is valuable to touch this use case with EBBR. Rather, the
> > primary use case for EBBR is embedded and community Linux distros on
> > embedded devices. Boot* variables are important, but hard to set at
> > runtime; therefore the question is "is setting Boot* variables only at
> > boot time suitable for EBBR use cases?"
>
> Windows IoT Core is addressing the same class of boards as EBBR and
> relies on UEFI:
>
>
> https://docs.microsoft.com/en-us/windows/iot-core/tutorials/quickstarter/PrototypeBoards
>
> https://docs.microsoft.com/en-us/windows/iot-core/commercialize-your-device/uefirequirements
>
> Best regards
>
> Heinrich
>
> >
> > (U-Boot could theoretically implement full SBBR on some platforms, but
> > that is different than what the EBBR requirements are)
> >
> >>> - "system administrator" is not the trusted party that has authority to
> >>> change a variable, a "platform administrator" has the authority and is
> >>> the signing party of variable updates.
> >>
> >> Not all variables are signed. Especially Boot* variables are managed by
> >> users with access to efibootmgr.
> >>
> >>> - UEFI variables interface for tools/kernel must not change: get/set
> >>> variable
> >>> - implementation of getVariable accesses a copy/shadow version of the
> >>> UEFI variable
> >>> - implementation of setVariable actually generates an update capsule so
> >>> that the variable update is seen at next reboot
> >>
> >> The discussion as far as I understood it centered on the question how a
> >> firmware that has no access to persistent memory at runtime can handle
> >> non-volatile variable updates.
> >>
> >> A capsule is only a possible encoding of information but does not answer
> >> the question in which medium the information from before the reboot
> >> shall be conveyed to after the reboot.
> >>
> >> Putting the information into RAM and hoping it survives a reboot is
> >> feasible but will not work during a system shutdown. Letting the
> >> operating system write the information to disk seems to be the easiest
> >> thing to do.
> >
> > Indeed, this debate always cycles back to this point. How does firmware
> > reliably persist a SetVariable() operation when it doesn't control the
> > storage, and the OS might not have a suitable storage proxy
> >
> > g.
>
>

-- 
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.o...@linaro.org | Skype: ffozog
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Re: RFC: EBBR specification update

On 3/19/20 1:21 PM, Grant Likely wrote:
>
>
> On 19/03/2020 12:03, Heinrich Schuchardt wrote:
>> On 3/19/20 12:31 PM, François Ozog wrote:
>
>>>
>>> I haven't followed the technical discussion. following is the original
>>> intent behind the changes requested for variable handling:
>>> - runtime services are not the best things and even EDK2 are probably
>>> moving away from this (Grant told us that at a design sprint a year ago)
>>
>> Operating systems like Windows rely on setting Boot* variables. Do you
>> plan to break them?
>
> If Windows is the goal, then SBSA/SBBR/ServerReady is the interface. I
> don't think it is valuable to touch this use case with EBBR. Rather, the
> primary use case for EBBR is embedded and community Linux distros on
> embedded devices. Boot* variables are important, but hard to set at
> runtime; therefore the question is "is setting Boot* variables only at
> boot time suitable for EBBR use cases?"

Windows IoT Core is addressing the same class of boards as EBBR and
relies on UEFI:

https://docs.microsoft.com/en-us/windows/iot-core/tutorials/quickstarter/PrototypeBoards
https://docs.microsoft.com/en-us/windows/iot-core/commercialize-your-device/uefirequirements

Best regards

Heinrich

>
> (U-Boot could theoretically implement full SBBR on some platforms, but
> that is different than what the EBBR requirements are)
>
>>> - "system administrator" is not the trusted party that has authority to
>>> change a variable, a "platform administrator" has the authority and is
>>> the signing party of variable updates.
>>
>> Not all variables are signed. Especially Boot* variables are managed by
>> users with access to efibootmgr.
>>
>>> - UEFI variables interface for tools/kernel must not change: get/set
>>> variable
>>> - implementation of getVariable accesses a copy/shadow version of the
>>> UEFI variable
>>> - implementation of setVariable actually generates an update capsule so
>>> that the variable update is seen at next reboot
>>
>> The discussion as far as I understood it centered on the question how a
>> firmware that has no access to persistent memory at runtime can handle
>> non-volatile variable updates.
>>
>> A capsule is only a possible encoding of information but does not answer
>> the question in which medium the information from before the reboot
>> shall be conveyed to after the reboot.
>>
>> Putting the information into RAM and hoping it survives a reboot is
>> feasible but will not work during a system shutdown. Letting the
>> operating system write the information to disk seems to be the easiest
>> thing to do.
>
> Indeed, this debate always cycles back to this point. How does firmware
> reliably persist a SetVariable() operation when it doesn't control the
> storage, and the OS might not have a suitable storage proxy
>
> g.

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Re: RFC: EBBR specification update

2020-03-19 Thread Grant Likely




On 19/03/2020 12:03, Heinrich Schuchardt wrote:

On 3/19/20 12:31 PM, François Ozog wrote:




I haven't followed the technical discussion. following is the original
intent behind the changes requested for variable handling:
- runtime services are not the best things and even EDK2 are probably
moving away from this (Grant told us that at a design sprint a year ago)


Operating systems like Windows rely on setting Boot* variables. Do you
plan to break them?


If Windows is the goal, then SBSA/SBBR/ServerReady is the interface. I 
don't think it is valuable to touch this use case with EBBR. Rather, the 
primary use case for EBBR is embedded and community Linux distros on 
embedded devices. Boot* variables are important, but hard to set at 
runtime; therefore the question is "is setting Boot* variables only at 
boot time suitable for EBBR use cases?"


(U-Boot could theoretically implement full SBBR on some platforms, but 
that is different than what the EBBR requirements are)



- "system administrator" is not the trusted party that has authority to
change a variable, a "platform administrator" has the authority and is
the signing party of variable updates.


Not all variables are signed. Especially Boot* variables are managed by
users with access to efibootmgr.


- UEFI variables interface for tools/kernel must not change: get/set
variable
- implementation of getVariable accesses a copy/shadow version of the
UEFI variable
- implementation of setVariable actually generates an update capsule so
that the variable update is seen at next reboot


The discussion as far as I understood it centered on the question how a
firmware that has no access to persistent memory at runtime can handle
non-volatile variable updates.

A capsule is only a possible encoding of information but does not answer
the question in which medium the information from before the reboot
shall be conveyed to after the reboot.

Putting the information into RAM and hoping it survives a reboot is
feasible but will not work during a system shutdown. Letting the
operating system write the information to disk seems to be the easiest
thing to do.


Indeed, this debate always cycles back to this point. How does firmware 
reliably persist a SetVariable() operation when it doesn't control the 
storage, and the OS might not have a suitable storage proxy


g.
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Re: RFC: EBBR specification update

2020-03-19 Thread Grant Likely

On 19/03/2020 11:31, François Ozog wrote:

On Thu, 19 Mar 2020 at 12:05, Leif Lindholm mailto:l...@nuviainc.com>> wrote:

Hi Ilias,

On Thu, Mar 19, 2020 at 12:33:30 +0200, Ilias Apalodimas wrote:
 > On Thu, Mar 19, 2020 at 10:45:31AM +0100, Heinrich Schuchardt wrote:
 > > > > As some of you may know, I'm going to submit a RFC patch
series for UEFI
 > > > > capsule support on U-Boot in a week or so (maybe). With
this patch,
 > > > > we will support "Capsule-on-Disk" only (but without
authentication
 > > > > implemented).
 > > > >
 > > > > One of my concerns here is about "variable update via a
capsule" as
 > > > > an alternative of "SetVariable at runtime," where values to
be set
 > > > > for variables will be exported as a capsule file and all
the updates
 > > > > will take place after rebooting. This is very useful on systems
 > > > > where SetVariable is not available at runtime for some reasons.
 > > > > Some idea has been proposed by Peter[1], but the discussion
has been
 > > > > stalled for a long time.
 > > > >
 > > > > [1]

https://lists.linaro.org/pipermail/boot-architecture/2018-October/000883.html
 > > >
 > > > So the way i understand it we got two paths we can follow:
 > > > 1. Use a configuration table for those variables
 > > > 2. Shadow the variables on a kernel accessible memory in
order to have access to
 > > > them
 > >
 > > It is unclear to me why it would be advantageous to follow any
of these
 > > ideas compared to using GetVariable and SetVariable and letting the
 > > firmware runtime manage the memory area.
 >
 > This describes some of the reasoning behind the idea.
 >

https://lists.linaro.org/pipermail/boot-architecture/2018-September/000841.html
 > The short version is that we should be able to provide
GetVariable() even if
 > SetVariable() is not implemented.

I'm pretty sure Heinrich's concerns with this description are similar
to my own, and boil down to one thing: this sounds like inventing new
interfaces for doing these operations on these systems.

Systems that support GetVariable need to support that without any
special handling added to the kernel.

For systems that have the flash sharing issue, this will mean that
U-Boot needs to copy the flash variable region into RAM at
ExitBootServices() time, and have the runtime service use this area.

Similarly, for such systems to support SetVariable they will need to
either:
- allocate some spare space for the GetVariable buffer and rewrite the
   whole thing on each write.
- allocate a separate memory region to accept write transactions into,
   and hook those transactions into the GetVariable lookup to remain
   consistent.

(The former isn't necessarily going to be less effort, and the latter
is almost certainly going to be required at some point.)

How and when any transactions become persisted in flash are separate
questions.

I haven't followed the technical discussion. following is the original
intent behind the changes requested for variable handling:
- runtime services are not the best things and even EDK2 are probably
moving away from this (Grant told us that at a design sprint a year ago)

As always, this is a matter of intense debate. Don't expect Runtime
Services to disappear anytime soon. The real question is what level of
service must be provided by EBBR platforms. I thing GetVariable() should
be required. SetVariable() I'm still undecided on, but I'm less and less
keen on inviting new mechanisms to replace it. I'd rather flag it as
unsupported and require the system operator to do their variable
manipulation at boot time for those specific systems.

- "system administrator" is not the trusted party that has authority to
change a variable, a "platform administrator" has the authority and is
the signing party of variable updates.

The moment we're talking about secure boot, a suitable design pretty
much requires moving all the variable management code out of normal
world and into a trusted application. In this case the runtime serivces
calls can become wrappers around SMC calls and we've got a lot more
capability to make changes. I think going forward, our focus for
complete functionality should be on the platforms that can implement the
back end as a trusted application and not get too hung up on the
complications of the non-secure platforms.

g.

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Re: RFC: EBBR specification update

2020-03-19 Thread Leif Lindholm

On Thu, Mar 19, 2020 at 12:31:37 +0100, François Ozog wrote:
> On Thu, 19 Mar 2020 at 12:05, Leif Lindholm  wrote:
> > I'm pretty sure Heinrich's concerns with this description are similar
> > to my own, and boil down to one thing: this sounds like inventing new
> > interfaces for doing these operations on these systems.
> >
> > Systems that support GetVariable need to support that without any
> > special handling added to the kernel.
> >
> > For systems that have the flash sharing issue, this will mean that
> > U-Boot needs to copy the flash variable region into RAM at
> > ExitBootServices() time, and have the runtime service use this area.
> >
> > Similarly, for such systems to support SetVariable they will need to
> > either:
> > - allocate some spare space for the GetVariable buffer and rewrite the
> >   whole thing on each write.
> > - allocate a separate memory region to accept write transactions into,
> >   and hook those transactions into the GetVariable lookup to remain
> >   consistent.
> >
> > (The former isn't necessarily going to be less effort, and the latter
> > is almost certainly going to be required at some point.)
> >
> > How and when any transactions become persisted in flash are separate
> > questions.
>
> I haven't followed the technical discussion. following is the original
> intent behind the changes requested for variable handling:
>
> - runtime services are not the best things and even EDK2 are probably
>   moving away from this (Grant told us that at a design sprint a year ago)

I'm pretty sure Grant said *UEFI*[0] might move away from them (if not,
bad Grant!). I think a more accurate description would be that UEFI
*wants* to move away from them. Even so, that's a push, and runtime
services are certainly going to remain relevant for the next decade or
two.

Discussing what may or may not happen is not an argument for diverging
from the existing specification, nor is it constructive to discuss
bolt-ons onto the side of the spec other than in the context of
proposing specific changes to the UEFI specification.

> - "system administrator" is not the trusted party that has authority to
>   change a variable, a "platform administrator" has the authority and is the
>   signing party of variable updates.
> - UEFI variables interface for tools/kernel must not change: get/set
>   variable

Yes, this is the sticking point.
GetVariable/SetVariable (where supported) must be implemented as
runtime services accessed through pointers in the EFI System Table.
No alternative mechanisms for getting/setting UEFI variables must be
implemented unless supported by a future UEFI specification.

> - implementation of getVariable accesses a copy/shadow version of the UEFI
>   variable

Yep. Without any knowledge on behalf of the operating system beyond
the addresses of the runtime service functions.

> - implementation of setVariable actually generates an update capsule so
>   that the variable update is seen at next reboot

I don't really have an opinion[1] - my statement was intended to
separate the discussion of the interfaces for accessing variables at
runtime from the discussion of mechanisms used to persist said
variables in a single-storage system.

/
Leif

[0] EDK2 is the reference implementation of UEFI, it isn't going to go
off and invent interfaces that aren't already resolved in the spec.

[1] This is obviously a lie.
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Re: RFC: EBBR specification update

On 3/19/20 12:31 PM, François Ozog wrote:
>
>
> On Thu, 19 Mar 2020 at 12:05, Leif Lindholm  > wrote:
>
> Hi Ilias,
>
> On Thu, Mar 19, 2020 at 12:33:30 +0200, Ilias Apalodimas wrote:
> > On Thu, Mar 19, 2020 at 10:45:31AM +0100, Heinrich Schuchardt wrote:
> > > > > As some of you may know, I'm going to submit a RFC patch
> series for UEFI
> > > > > capsule support on U-Boot in a week or so (maybe). With this
> patch,
> > > > > we will support "Capsule-on-Disk" only (but without
> authentication
> > > > > implemented).
> > > > >
> > > > > One of my concerns here is about "variable update via a
> capsule" as
> > > > > an alternative of "SetVariable at runtime," where values to
> be set
> > > > > for variables will be exported as a capsule file and all the
> updates
> > > > > will take place after rebooting. This is very useful on systems
> > > > > where SetVariable is not available at runtime for some reasons.
> > > > > Some idea has been proposed by Peter[1], but the discussion
> has been
> > > > > stalled for a long time.
> > > > >
> > > > > [1]
> 
> https://lists.linaro.org/pipermail/boot-architecture/2018-October/000883.html
> > > >
> > > > So the way i understand it we got two paths we can follow:
> > > > 1. Use a configuration table for those variables
> > > > 2. Shadow the variables on a kernel accessible memory in order
> to have access to
> > > > them
> > >
> > > It is unclear to me why it would be advantageous to follow any
> of these
> > > ideas compared to using GetVariable and SetVariable and letting the
> > > firmware runtime manage the memory area.
> >
> > This describes some of the reasoning behind the idea.
> >
> 
> https://lists.linaro.org/pipermail/boot-architecture/2018-September/000841.html
> > The short version is that we should be able to provide
> GetVariable() even if
> > SetVariable() is not implemented.
>
> I'm pretty sure Heinrich's concerns with this description are similar
> to my own, and boil down to one thing: this sounds like inventing new
> interfaces for doing these operations on these systems.
>
> Systems that support GetVariable need to support that without any
> special handling added to the kernel.
>
> For systems that have the flash sharing issue, this will mean that
> U-Boot needs to copy the flash variable region into RAM at
> ExitBootServices() time, and have the runtime service use this area.
>
> Similarly, for such systems to support SetVariable they will need to
> either:
> - allocate some spare space for the GetVariable buffer and rewrite the
>   whole thing on each write.
> - allocate a separate memory region to accept write transactions into,
>   and hook those transactions into the GetVariable lookup to remain
>   consistent.
>
> (The former isn't necessarily going to be less effort, and the latter
> is almost certainly going to be required at some point.)
>
> How and when any transactions become persisted in flash are separate
> questions.
>
> I haven't followed the technical discussion. following is the original
> intent behind the changes requested for variable handling:
> - runtime services are not the best things and even EDK2 are probably
> moving away from this (Grant told us that at a design sprint a year ago)

Operating systems like Windows rely on setting Boot* variables. Do you
plan to break them?

> - "system administrator" is not the trusted party that has authority to
> change a variable, a "platform administrator" has the authority and is
> the signing party of variable updates.

Not all variables are signed. Especially Boot* variables are managed by
users with access to efibootmgr.

> - UEFI variables interface for tools/kernel must not change: get/set
> variable
> - implementation of getVariable accesses a copy/shadow version of the
> UEFI variable
> - implementation of setVariable actually generates an update capsule so
> that the variable update is seen at next reboot

The discussion as far as I understood it centered on the question how a
firmware that has no access to persistent memory at runtime can handle
non-volatile variable updates.

A capsule is only a possible encoding of information but does not answer
the question in which medium the information from before the reboot
shall be conveyed to after the reboot.

Putting the information into RAM and hoping it survives a reboot is
feasible but will not work during a system shutdown. Letting the
operating system write the information to disk seems to be the easiest
thing to do.

Best regards

Heinrich
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Re: RFC: EBBR specification update

On 3/19/20 12:05 PM, Leif Lindholm wrote:
> Hi Ilias,
>
> On Thu, Mar 19, 2020 at 12:33:30 +0200, Ilias Apalodimas wrote:
>> On Thu, Mar 19, 2020 at 10:45:31AM +0100, Heinrich Schuchardt wrote:
> As some of you may know, I'm going to submit a RFC patch series for UEFI
> capsule support on U-Boot in a week or so (maybe). With this patch,
> we will support "Capsule-on-Disk" only (but without authentication
> implemented).
>
> One of my concerns here is about "variable update via a capsule" as
> an alternative of "SetVariable at runtime," where values to be set
> for variables will be exported as a capsule file and all the updates
> will take place after rebooting. This is very useful on systems
> where SetVariable is not available at runtime for some reasons.
> Some idea has been proposed by Peter[1], but the discussion has been
> stalled for a long time.
>
> [1] 
> https://lists.linaro.org/pipermail/boot-architecture/2018-October/000883.html

 So the way i understand it we got two paths we can follow:
 1. Use a configuration table for those variables
 2. Shadow the variables on a kernel accessible memory in order to have 
 access to
 them
>>>
>>> It is unclear to me why it would be advantageous to follow any of these
>>> ideas compared to using GetVariable and SetVariable and letting the
>>> firmware runtime manage the memory area.
>>
>> This describes some of the reasoning behind the idea.
>> https://lists.linaro.org/pipermail/boot-architecture/2018-September/000841.html
>> The short version is that we should be able to provide GetVariable() even if
>> SetVariable() is not implemented.
>
> I'm pretty sure Heinrich's concerns with this description are similar
> to my own, and boil down to one thing: this sounds like inventing new
> interfaces for doing these operations on these systems.
>
> Systems that support GetVariable need to support that without any
> special handling added to the kernel.
>
> For systems that have the flash sharing issue, this will mean that
> U-Boot needs to copy the flash variable region into RAM at
> ExitBootServices() time, and have the runtime service use this area.
>
> Similarly, for such systems to support SetVariable they will need to
> either:
> - allocate some spare space for the GetVariable buffer and rewrite the
>   whole thing on each write.
> - allocate a separate memory region to accept write transactions into,
>   and hook those transactions into the GetVariable lookup to remain
>   consistent.

If the firmware that has no persistent storage but holds all variables
in memory, an operating system shutdown service (e.g. a script in
systemd's /usr/lib/systemd/system-shutdown/) could be used to persist
the variables before reboot. The service would read all variable via
Get(Next)Variable and write a file to the EFI boot partition. This could
be an EFI update capsule or some system specific file format.

Best regards

Heinrich

>
> (The former isn't necessarily going to be less effort, and the latter
> is almost certainly going to be required at some point.)
>
> How and when any transactions become persisted in flash are separate
> questions.
>
> /
> Leif
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Re: RFC: EBBR specification update

2020-03-19 Thread François Ozog

On Thu, 19 Mar 2020 at 12:05, Leif Lindholm  wrote:

> Hi Ilias,
>
> On Thu, Mar 19, 2020 at 12:33:30 +0200, Ilias Apalodimas wrote:
> > On Thu, Mar 19, 2020 at 10:45:31AM +0100, Heinrich Schuchardt wrote:
> > > > > As some of you may know, I'm going to submit a RFC patch series
> for UEFI
> > > > > capsule support on U-Boot in a week or so (maybe). With this patch,
> > > > > we will support "Capsule-on-Disk" only (but without authentication
> > > > > implemented).
> > > > >
> > > > > One of my concerns here is about "variable update via a capsule" as
> > > > > an alternative of "SetVariable at runtime," where values to be set
> > > > > for variables will be exported as a capsule file and all the
> updates
> > > > > will take place after rebooting. This is very useful on systems
> > > > > where SetVariable is not available at runtime for some reasons.
> > > > > Some idea has been proposed by Peter[1], but the discussion has
> been
> > > > > stalled for a long time.
> > > > >
> > > > > [1]
> https://lists.linaro.org/pipermail/boot-architecture/2018-October/000883.html
> > > >
> > > > So the way i understand it we got two paths we can follow:
> > > > 1. Use a configuration table for those variables
> > > > 2. Shadow the variables on a kernel accessible memory in order to
> have access to
> > > > them
> > >
> > > It is unclear to me why it would be advantageous to follow any of these
> > > ideas compared to using GetVariable and SetVariable and letting the
> > > firmware runtime manage the memory area.
> >
> > This describes some of the reasoning behind the idea.
> >
> https://lists.linaro.org/pipermail/boot-architecture/2018-September/000841.html
> > The short version is that we should be able to provide GetVariable()
> even if
> > SetVariable() is not implemented.
>
> I'm pretty sure Heinrich's concerns with this description are similar
> to my own, and boil down to one thing: this sounds like inventing new
> interfaces for doing these operations on these systems.
>
> Systems that support GetVariable need to support that without any
> special handling added to the kernel.
>
> For systems that have the flash sharing issue, this will mean that
> U-Boot needs to copy the flash variable region into RAM at
> ExitBootServices() time, and have the runtime service use this area.
>
> Similarly, for such systems to support SetVariable they will need to
> either:
> - allocate some spare space for the GetVariable buffer and rewrite the
>   whole thing on each write.
> - allocate a separate memory region to accept write transactions into,
>   and hook those transactions into the GetVariable lookup to remain
>   consistent.
>
> (The former isn't necessarily going to be less effort, and the latter
> is almost certainly going to be required at some point.)
>
> How and when any transactions become persisted in flash are separate
> questions.
>
> I haven't followed the technical discussion. following is the original
intent behind the changes requested for variable handling:
- runtime services are not the best things and even EDK2 are probably
moving away from this (Grant told us that at a design sprint a year ago)
- "system administrator" is not the trusted party that has authority to
change a variable, a "platform administrator" has the authority and is the
signing party of variable updates.
- UEFI variables interface for tools/kernel must not change: get/set
variable
- implementation of getVariable accesses a copy/shadow version of the UEFI
variable
- implementation of setVariable actually generates an update capsule so
that the variable update is seen at next reboot

> /
> Leif
>


-- 
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.o...@linaro.org | Skype: ffozog
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Re: RFC: EBBR specification update

2020-03-19 Thread Leif Lindholm

Hi Ilias,

On Thu, Mar 19, 2020 at 12:33:30 +0200, Ilias Apalodimas wrote:
> On Thu, Mar 19, 2020 at 10:45:31AM +0100, Heinrich Schuchardt wrote:
> > > > As some of you may know, I'm going to submit a RFC patch series for UEFI
> > > > capsule support on U-Boot in a week or so (maybe). With this patch,
> > > > we will support "Capsule-on-Disk" only (but without authentication
> > > > implemented).
> > > > 
> > > > One of my concerns here is about "variable update via a capsule" as
> > > > an alternative of "SetVariable at runtime," where values to be set
> > > > for variables will be exported as a capsule file and all the updates
> > > > will take place after rebooting. This is very useful on systems
> > > > where SetVariable is not available at runtime for some reasons.
> > > > Some idea has been proposed by Peter[1], but the discussion has been
> > > > stalled for a long time.
> > > > 
> > > > [1] 
> > > > https://lists.linaro.org/pipermail/boot-architecture/2018-October/000883.html
> > > 
> > > So the way i understand it we got two paths we can follow:
> > > 1. Use a configuration table for those variables
> > > 2. Shadow the variables on a kernel accessible memory in order to have 
> > > access to
> > > them
> > 
> > It is unclear to me why it would be advantageous to follow any of these
> > ideas compared to using GetVariable and SetVariable and letting the
> > firmware runtime manage the memory area.
> 
> This describes some of the reasoning behind the idea.
> https://lists.linaro.org/pipermail/boot-architecture/2018-September/000841.html
> The short version is that we should be able to provide GetVariable() even if 
> SetVariable() is not implemented.

I'm pretty sure Heinrich's concerns with this description are similar
to my own, and boil down to one thing: this sounds like inventing new
interfaces for doing these operations on these systems.

Systems that support GetVariable need to support that without any
special handling added to the kernel.

For systems that have the flash sharing issue, this will mean that
U-Boot needs to copy the flash variable region into RAM at
ExitBootServices() time, and have the runtime service use this area.

Similarly, for such systems to support SetVariable they will need to
either:
- allocate some spare space for the GetVariable buffer and rewrite the
  whole thing on each write.
- allocate a separate memory region to accept write transactions into,
  and hook those transactions into the GetVariable lookup to remain
  consistent.

(The former isn't necessarily going to be less effort, and the latter
is almost certainly going to be required at some point.)

How and when any transactions become persisted in flash are separate
questions.

/
Leif
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Re: RFC: EBBR specification update

On 3/19/20 11:33 AM, Ilias Apalodimas wrote:
> On Thu, Mar 19, 2020 at 10:45:31AM +0100, Heinrich Schuchardt wrote:
>> On 3/19/20 10:33 AM, Ilias Apalodimas wrote:
>>> Akashi-san,
>>>
>>> On Wed, Mar 11, 2020 at 03:56:53PM +0900, AKASHI Takahiro wrote:
 Regarding capsule update,

 On Tue, Mar 10, 2020 at 09:45:28PM +0100, Francois Ozog wrote:
>>
>>>
>>> [...]
>>>
>> Directory \EFI\UpdateCapsule - A file placed on this directory on the
>> boot device is considered a capsule. This is much easier to implement.
>>
>> Essentially you could also use BootNext to run any binary for updating.
>>
>> I suggest to go for the directory method of capsule updating.
>>
> That’s the goal for the moment. Yet a whole bunch new to be clarified. We
> are working on a document to be commented.

 As some of you may know, I'm going to submit a RFC patch series for UEFI
 capsule support on U-Boot in a week or so (maybe). With this patch,
 we will support "Capsule-on-Disk" only (but without authentication
 implemented).

 One of my concerns here is about "variable update via a capsule" as
 an alternative of "SetVariable at runtime," where values to be set
 for variables will be exported as a capsule file and all the updates
 will take place after rebooting. This is very useful on systems
 where SetVariable is not available at runtime for some reasons.
 Some idea has been proposed by Peter[1], but the discussion has been
 stalled for a long time.

 [1] 
 https://lists.linaro.org/pipermail/boot-architecture/2018-October/000883.html
>>>
>>> So the way i understand it we got two paths we can follow:
>>> 1. Use a configuration table for those variables
>>> 2. Shadow the variables on a kernel accessible memory in order to have 
>>> access to
>>> them
>>
>> It is unclear to me why it would be advantageous to follow any of these
>> ideas compared to using GetVariable and SetVariable and letting the
>> firmware runtime manage the memory area.
>
> This describes some of the reasoning behind the idea.
> https://lists.linaro.org/pipermail/boot-architecture/2018-September/000841.html
> The short version is that we should be able to provide GetVariable() even if
> SetVariable() is not implemented.

Thanks for the link. Unfortunately it does not answer my question. Why
do we need a configuration table and cannot use GetVariable() and
SetVariable() for abstracting the memory store?

For telling the kernel that the firmware cannot persist non-volatile
variables on its own you could use a variable or a bit in the
RuntimeServicesSupported variable.

Best regards

Heinrich
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Re: RFC: EBBR specification update

2020-03-19 Thread Ilias Apalodimas

On Thu, Mar 19, 2020 at 10:45:31AM +0100, Heinrich Schuchardt wrote:
> On 3/19/20 10:33 AM, Ilias Apalodimas wrote:
> > Akashi-san,
> > 
> > On Wed, Mar 11, 2020 at 03:56:53PM +0900, AKASHI Takahiro wrote:
> > > Regarding capsule update,
> > > 
> > > On Tue, Mar 10, 2020 at 09:45:28PM +0100, Francois Ozog wrote:
> > > > > 
> > 
> > [...]
> > 
> > > > > Directory \EFI\UpdateCapsule - A file placed on this directory on the
> > > > > boot device is considered a capsule. This is much easier to implement.
> > > > > 
> > > > > Essentially you could also use BootNext to run any binary for 
> > > > > updating.
> > > > > 
> > > > > I suggest to go for the directory method of capsule updating.
> > > > > 
> > > > That’s the goal for the moment. Yet a whole bunch new to be clarified. 
> > > > We
> > > > are working on a document to be commented.
> > > 
> > > As some of you may know, I'm going to submit a RFC patch series for UEFI
> > > capsule support on U-Boot in a week or so (maybe). With this patch,
> > > we will support "Capsule-on-Disk" only (but without authentication
> > > implemented).
> > > 
> > > One of my concerns here is about "variable update via a capsule" as
> > > an alternative of "SetVariable at runtime," where values to be set
> > > for variables will be exported as a capsule file and all the updates
> > > will take place after rebooting. This is very useful on systems
> > > where SetVariable is not available at runtime for some reasons.
> > > Some idea has been proposed by Peter[1], but the discussion has been
> > > stalled for a long time.
> > > 
> > > [1] 
> > > https://lists.linaro.org/pipermail/boot-architecture/2018-October/000883.html
> > 
> > So the way i understand it we got two paths we can follow:
> > 1. Use a configuration table for those variables
> > 2. Shadow the variables on a kernel accessible memory in order to have 
> > access to
> > them
> 
> It is unclear to me why it would be advantageous to follow any of these
> ideas compared to using GetVariable and SetVariable and letting the
> firmware runtime manage the memory area.

This describes some of the reasoning behind the idea.
https://lists.linaro.org/pipermail/boot-architecture/2018-September/000841.html
The short version is that we should be able to provide GetVariable() even if 
SetVariable() is not implemented.

Regards
/Ilias
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Re: RFC: EBBR specification update


On 3/19/20 10:33 AM, Ilias Apalodimas wrote:

Akashi-san,

On Wed, Mar 11, 2020 at 03:56:53PM +0900, AKASHI Takahiro wrote:

Regarding capsule update,

On Tue, Mar 10, 2020 at 09:45:28PM +0100, Francois Ozog wrote:




[...]


Directory \EFI\UpdateCapsule - A file placed on this directory on the
boot device is considered a capsule. This is much easier to implement.

Essentially you could also use BootNext to run any binary for updating.

I suggest to go for the directory method of capsule updating.


That’s the goal for the moment. Yet a whole bunch new to be clarified. We
are working on a document to be commented.


As some of you may know, I'm going to submit a RFC patch series for UEFI
capsule support on U-Boot in a week or so (maybe). With this patch,
we will support "Capsule-on-Disk" only (but without authentication
implemented).

One of my concerns here is about "variable update via a capsule" as
an alternative of "SetVariable at runtime," where values to be set
for variables will be exported as a capsule file and all the updates
will take place after rebooting. This is very useful on systems
where SetVariable is not available at runtime for some reasons.
Some idea has been proposed by Peter[1], but the discussion has been
stalled for a long time.

[1] 
https://lists.linaro.org/pipermail/boot-architecture/2018-October/000883.html


So the way i understand it we got two paths we can follow:
1. Use a configuration table for those variables
2. Shadow the variables on a kernel accessible memory in order to have access to
them


It is unclear to me why it would be advantageous to follow any of these
ideas compared to using GetVariable and SetVariable and letting the
firmware runtime manage the memory area.

Best regards

Heinrich



How is this going to affect the existing tools (i.e efivar --list) for reading
variables?

Regards
/Ilias
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Re: RFC: EBBR specification update

2020-03-19 Thread Ilias Apalodimas

Akashi-san,

On Wed, Mar 11, 2020 at 03:56:53PM +0900, AKASHI Takahiro wrote:
> Regarding capsule update,
> 
> On Tue, Mar 10, 2020 at 09:45:28PM +0100, Francois Ozog wrote:
> > >

[...]

> > > Directory \EFI\UpdateCapsule - A file placed on this directory on the
> > > boot device is considered a capsule. This is much easier to implement.
> > >
> > > Essentially you could also use BootNext to run any binary for updating.
> > >
> > > I suggest to go for the directory method of capsule updating.
> > >
> > That’s the goal for the moment. Yet a whole bunch new to be clarified. We
> > are working on a document to be commented.
> 
> As some of you may know, I'm going to submit a RFC patch series for UEFI
> capsule support on U-Boot in a week or so (maybe). With this patch,
> we will support "Capsule-on-Disk" only (but without authentication
> implemented).
> 
> One of my concerns here is about "variable update via a capsule" as
> an alternative of "SetVariable at runtime," where values to be set
> for variables will be exported as a capsule file and all the updates
> will take place after rebooting. This is very useful on systems
> where SetVariable is not available at runtime for some reasons.
> Some idea has been proposed by Peter[1], but the discussion has been
> stalled for a long time.
> 
> [1] 
> https://lists.linaro.org/pipermail/boot-architecture/2018-October/000883.html

So the way i understand it we got two paths we can follow:
1. Use a configuration table for those variables
2. Shadow the variables on a kernel accessible memory in order to have access to
them 

How is this going to affect the existing tools (i.e efivar --list) for reading
variables?

Regards
/Ilias
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Re: RFC: EBBR specification update

2020-03-12 Thread Sumit Garg

On Thu, 12 Mar 2020 at 20:43, Stuart Yoder  wrote:
>
>
> >>> https://buyzero.de/products/letstrust-hardware-tpm-trusted-platform-module?variant=33890452626
> >>>
> >>> Would we be able to use this as root of trust?
> >
> > AFAIK, TPM in itself can't act as a root of trust. It is rather a
> > passive device which can provide you with trusted/secure services. In
> > general a root of trust is the first piece of *non-modifiable* code
> > that runs on a platform which is BootROM that establishes the chain of
> > trust via verifying the first stage boot-loader which in turn
> > continues the chain of trust to next boot stages and so on.
>
> You do need to take care with "root of trust" terminology.
>
> A root of trust is something that is inherently trusted, and in which
> a compromise can't be detected.  There are various terminology schemes
> proposed from GlobalPlatform, TCG, NIST-- e.g. roots of trust for: update,
> verification, measurement, storage, reporting, etc.
>
> So a boot ROM is _a_ root of trust-- for example a root of trust for
> verification.
>
> A TPM is a root of trust for storage (i.e. securely storing measurements)
> and for reporting (i.e. providing cryptographically signed attestation
> reports).
>
> So, it depends what you mean.
>

I guess the context of discussion was pretty clear in this regard:
"Secure boot for Raspberries", no?

BTW, in general I agree with you that one shouldn't confuse "root of
trust for Secure boot" with "root of trust for storage or reporting".

-Sumit

>
> Thanks,
> Stuart
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Re: RFC: EBBR specification update

2020-03-12 Thread Stuart Yoder




https://buyzero.de/products/letstrust-hardware-tpm-trusted-platform-module?variant=33890452626

Would we be able to use this as root of trust?


AFAIK, TPM in itself can't act as a root of trust. It is rather a
passive device which can provide you with trusted/secure services. In
general a root of trust is the first piece of *non-modifiable* code
that runs on a platform which is BootROM that establishes the chain of
trust via verifying the first stage boot-loader which in turn
continues the chain of trust to next boot stages and so on.


You do need to take care with "root of trust" terminology.

A root of trust is something that is inherently trusted, and in which
a compromise can't be detected.  There are various terminology schemes
proposed from GlobalPlatform, TCG, NIST-- e.g. roots of trust for: update,
verification, measurement, storage, reporting, etc.

So a boot ROM is _a_ root of trust-- for example a root of trust for
verification.

A TPM is a root of trust for storage (i.e. securely storing measurements)
and for reporting (i.e. providing cryptographically signed attestation
reports).

So, it depends what you mean.


Thanks,
Stuart
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Re: RFC: EBBR specification update

2020-03-12 Thread Ilias Apalodimas

Akashi-san

On Wed, Mar 11, 2020 at 03:56:53PM +0900, AKASHI Takahiro wrote:
> Regarding capsule update,
[...]
> 
> As some of you may know, I'm going to submit a RFC patch series for UEFI
> capsule support on U-Boot in a week or so (maybe). With this patch,
> we will support "Capsule-on-Disk" only (but without authentication
> implemented).
> 
> One of my concerns here is about "variable update via a capsule" as
> an alternative of "SetVariable at runtime," where values to be set
> for variables will be exported as a capsule file and all the updates
> will take place after rebooting. This is very useful on systems
> where SetVariable is not available at runtime for some reasons.

Sure that's really useful and that's the direction we decided to follow.

> Some idea has been proposed by Peter[1], but the discussion has been
> stalled for a long time.
> 
> [1] 
> https://lists.linaro.org/pipermail/boot-architecture/2018-October/000883.html

We hope to allocate some resources and work on it in the following months, 
so we'll revive this thread once we do. 
Thanks for the pointers. 

Regards
/Ilias
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Re: RFC: EBBR specification update

2020-03-12 Thread Ilias Apalodimas

Hi Francois, 

On Tue, Mar 10, 2020 at 05:35:40PM +0100, Francois Ozog wrote:
> On Tue, 10 Mar 2020 at 17:18, Grant Likely  wrote:
> >
> > Hi Francois,
> >
> > This is really good. EBBR regular meetings have been on hold while the
> > U-Boot work progressed, but it is probably about time to start them up
> > again. This is list is a great first agenda item.
> >
> > Comments below...
> >
> > On 10/03/2020 16:02, Francois Ozog wrote:
> > > Hi,
> > >
> > > Following implementation (or work towards) of EBBR 1.0 + UEFI Secure
> > > boot + UEFI update capsule we learnt a lot.
> > >
> > > Here are some topics that may need some clarification on the EBBR
> > > specs and It looks timely to start working on EBBR evolution.
> > >
> > > 0.1 - EBBR goal
> > > May be a reassessment on the "for what" the specification is built.
> > >
> > > Following all the discussions with prominent industry players, I start
> > > to think that limiting the constraints to be EBBR compliant may become
> > > counter productive. There will be both EBBR non compliant and EBBR
> > > compliant systems. This is inevitable. But EBBR exist for a number of
> > > use cases in a number of markets. The value of EBBR is consistent
> > > behavior across those.
> > >
> > > Maximising number of EBBR compliant systems without stating use case
> > > parameters ( "why" and "for what") may not be the best goal.
> > >
> 
> I would like people to think about this one before getting into the
> meeting because without this we can't discuss most of the rest.
> 
> > > Out of things to be more explicit are supported secure boot flows
> > > (with/without shim+grub or direct). Some vendors require shim+grub
> > > while industry players want the exact opposite: nothing but UEFI. This
> > > drivers a number of requirements in terms of UEFI protocols needed
> >
> > Have you got a comparison of the protocols needed in each scenario? It
> > has been pretty clear that both models are important, is there a large
> > delta from one to the other, and it is an extra burden to support all of
> > them in U-Boot (e.g., once implemented in mainline, most of the
> > protocols should work for all).
> >
> 
> Supporting industrial players require EFI_LOAD_FILE2_PROTOCOL in
> addition to the distro subset.
> Pushed upstream. Ilias may comment about merging

This is in U-Boot already and should go in kernel 5.7. IIRC EDK2 also got a
command line to register and use the protocol.

The idea behind this is that we use a number of different and rather complicated
ways of passing the initrd to the kernel.
This is an arch-agnostic approach. The kernel efi stub allocates a memory 
during booting and requests the firmware for the file right before it needs to
run it.

Nothing authenticates the file, but on U-boot for example, the file name is a
config option, thus built-in into U-Boot. In conjuction with TF-A verifying the
bootloader it offers some kind of (maybe naive??) security since you can't
change the file location. A user can still overwrite the initrd contents though.
There's ways to verify the initrd itself on linux if that's necessary.

> 
> But I am flexible, important we state explicitly the reference
> document and we use the language constructs.
[...]
> 
> > > I - protective offsets

Regards
/Ilias
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Re: RFC: EBBR specification update

2020-03-12 Thread Ilias Apalodimas

Hi,

Sorry for joining in late

[...]
> > The 1MB was to deal with limitations in the boot rom. If the boot rom
> > needs extra space, would it not be better to have an initial loader that
> > understands partitioning in the 1st 1MB and load the remaining images
> > from a real partition?
> 
> This is driven by the BL2 which is platform specific and I am not sure
> we can have any influence.
> The flashimage.bin in a number of system consists of a (blob) FIP that
> has BL2, SCP stuff, BL31, BL32, BL33.
> Ilias upstream U-Boot patches to change from "ADR" to "ADRL" because
> the code grew too much.

Not U-boot but OP-TEE but the case stands

> 
> >
> > > EBBR same paragraph also states:
> > > "Automatic partitioning tools (e.g. an OS installer) must not create


Regards
/Ilias
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Re: RFC: EBBR specification update

2020-03-11 Thread Sumit Garg

On Thu, 12 Mar 2020 at 03:11, Francois Ozog  wrote:
>
> Le mer. 11 mars 2020 à 22:22, Heinrich Schuchardt  a
> écrit :
>
> > On 3/11/20 12:10 PM, Daniel Thompson wrote:
> > > On Tue, Mar 10, 2020 at 06:34:35PM +0100, Francois Ozog wrote:
> > >> On Tue, 10 Mar 2020 at 18:19, Daniel Thompson <
> > daniel.thomp...@linaro.org>
> > >> wrote:
> > >>
> > >>> On Tue, Mar 10, 2020 at 05:02:27PM +0100, Francois Ozog wrote:
> >  0.1 - EBBR goal
> >  May be a reassessment on the "for what" the specification is built.
> > 
> >  Following all the discussions with prominent industry players, I start
> >  to think that limiting the constraints to be EBBR compliant may become
> >  counter productive. There will be both EBBR non compliant and EBBR
> >  compliant systems. This is inevitable. But EBBR exist for a number of
> >  use cases in a number of markets. The value of EBBR is consistent
> >  behavior across those.
> > 
> >  Maximising number of EBBR compliant systems without stating use case
> >  parameters ( "why" and "for what") may not be the best goal.
> > 
> >  Out of things to be more explicit are supported secure boot flows
> >  (with/without shim+grub or direct). Some vendors require shim+grub
> >  while industry players want the exact opposite: nothing but UEFI. This
> >  drivers a number of requirements in terms of UEFI protocols needed
> > >>>
> > >>> We have resisted levels in EBBR until now but this might be where might
> > >>> have a need for them.
> > >>>
> > >>> Put another way I agree that getting explicit about mandatory features
> > >>> for secure boot flows is useful.
> > >>>
> > >>> However I also think that is remains valuable to define best practice
> > >>> for how firmware and OS interact on systems that have not implemented
> > >>> secure boot.
> > >>>
> > >>> It's all about the target use:
> > >> 1) industrial (manufacturing, automotive, robotics, medical...)
> > components
> > >> 2) telecom edge
> > >> 3) 96boards
> > >> 4) developer desktop
> > >> 5) server
> > >>
> > >> As I just consider 1 and 2, I have no case without secure boot...
> > >> Now the dev platform can come without the secureboot active and
> > >> SElinx deactivated
> > >> In what context you think this is usefull?
> > >
> > > I would like it to be possible for dev boards and SoMs whose SoCs do not
> > > have a built-in root of trust to have some basic level of EBBR
> > > compliance.
> > >
> > > I don't like to optics of saying "this standard cannot possibly apply to
> > > a Raspberry Pi"[1]. Taking the RPi Zero or CM3 as examples[2], I can't
> > see any
> > > value added by secure boot since the root-of-trust would have to start
> > > on the same media as the operating system anyway.
> >
> > There is a TPMv2 module available for Raspberries.
> >
> >
> > https://buyzero.de/products/letstrust-hardware-tpm-trusted-platform-module?variant=33890452626
> >
> > Would we be able to use this as root of trust?

AFAIK, TPM in itself can't act as a root of trust. It is rather a
passive device which can provide you with trusted/secure services. In
general a root of trust is the first piece of *non-modifiable* code
that runs on a platform which is BootROM that establishes the chain of
trust via verifying the first stage boot-loader which in turn
continues the chain of trust to next boot stages and so on.

> >
> > Would we recommend the EFI TPM2 Protocol to be implemented in the EBBR
> > as a possible source of trust? Daniel Kiper, one of the maintainers of
> > GRUB, expressed interest in this feature.
>
>
> > TPMv2 is definitely a big topic. We also implemented an OPTEE one. We will
> star working on measured boot next cycle (staring April) tf-a team is ready
> for that.
>

In case of measured boot too, either you need BootROM being root of
trust or first stage boot-loader verified by BootROM to measure next
boot stages and invoke TPM to store/update hash in PCR register. TPM
doesn't do the measurements by itself.

-Sumit

> >
> >
> > https://trustedcomputinggroup.org/wp-content/uploads/EFI-Protocol-Specification-rev13-160330final.pdf
> >
> > Best regards
> >
> > Heinrich
> >
> > >
> > >
> > > Daniel.
> > >
> > >
> > > [1] I'd also worried about some of the open-market Arm SoMs as well,
> > >  but since 96Boards has skin in the game there I've adopted a
> > >  less partisan example above.
> > >
> > > [2] There are problems with RPi4 too but they are different (and
> > >  hopefully less severe).
> > >
> > > ___
> > > boot-architecture mailing list
> > > boot-architecture@lists.linaro.org
> > > https://lists.linaro.org/mailman/listinfo/boot-architecture
> > >
> >
> > --
> François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
> T: +33.67221.6485
> francois.o...@linaro.org | Skype: ffozog
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Re: RFC: EBBR specification update

2020-03-11 Thread Francois Ozog

Le mer. 11 mars 2020 à 22:22, Heinrich Schuchardt  a
écrit :

> On 3/11/20 12:10 PM, Daniel Thompson wrote:
> > On Tue, Mar 10, 2020 at 06:34:35PM +0100, Francois Ozog wrote:
> >> On Tue, 10 Mar 2020 at 18:19, Daniel Thompson <
> daniel.thomp...@linaro.org>
> >> wrote:
> >>
> >>> On Tue, Mar 10, 2020 at 05:02:27PM +0100, Francois Ozog wrote:
>  0.1 - EBBR goal
>  May be a reassessment on the "for what" the specification is built.
> 
>  Following all the discussions with prominent industry players, I start
>  to think that limiting the constraints to be EBBR compliant may become
>  counter productive. There will be both EBBR non compliant and EBBR
>  compliant systems. This is inevitable. But EBBR exist for a number of
>  use cases in a number of markets. The value of EBBR is consistent
>  behavior across those.
> 
>  Maximising number of EBBR compliant systems without stating use case
>  parameters ( "why" and "for what") may not be the best goal.
> 
>  Out of things to be more explicit are supported secure boot flows
>  (with/without shim+grub or direct). Some vendors require shim+grub
>  while industry players want the exact opposite: nothing but UEFI. This
>  drivers a number of requirements in terms of UEFI protocols needed
> >>>
> >>> We have resisted levels in EBBR until now but this might be where might
> >>> have a need for them.
> >>>
> >>> Put another way I agree that getting explicit about mandatory features
> >>> for secure boot flows is useful.
> >>>
> >>> However I also think that is remains valuable to define best practice
> >>> for how firmware and OS interact on systems that have not implemented
> >>> secure boot.
> >>>
> >>> It's all about the target use:
> >> 1) industrial (manufacturing, automotive, robotics, medical...)
> components
> >> 2) telecom edge
> >> 3) 96boards
> >> 4) developer desktop
> >> 5) server
> >>
> >> As I just consider 1 and 2, I have no case without secure boot...
> >> Now the dev platform can come without the secureboot active and
> >> SElinx deactivated
> >> In what context you think this is usefull?
> >
> > I would like it to be possible for dev boards and SoMs whose SoCs do not
> > have a built-in root of trust to have some basic level of EBBR
> > compliance.
> >
> > I don't like to optics of saying "this standard cannot possibly apply to
> > a Raspberry Pi"[1]. Taking the RPi Zero or CM3 as examples[2], I can't
> see any
> > value added by secure boot since the root-of-trust would have to start
> > on the same media as the operating system anyway.
>
> There is a TPMv2 module available for Raspberries.
>
>
> https://buyzero.de/products/letstrust-hardware-tpm-trusted-platform-module?variant=33890452626
>
> Would we be able to use this as root of trust?
>
> Would we recommend the EFI TPM2 Protocol to be implemented in the EBBR
> as a possible source of trust? Daniel Kiper, one of the maintainers of
> GRUB, expressed interest in this feature.


> TPMv2 is definitely a big topic. We also implemented an OPTEE one. We will
star working on measured boot next cycle (staring April) tf-a team is ready
for that.

>
>
> https://trustedcomputinggroup.org/wp-content/uploads/EFI-Protocol-Specification-rev13-160330final.pdf
>
> Best regards
>
> Heinrich
>
> >
> >
> > Daniel.
> >
> >
> > [1] I'd also worried about some of the open-market Arm SoMs as well,
> >  but since 96Boards has skin in the game there I've adopted a
> >  less partisan example above.
> >
> > [2] There are problems with RPi4 too but they are different (and
> >  hopefully less severe).
> >
> > ___
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> > boot-architecture@lists.linaro.org
> > https://lists.linaro.org/mailman/listinfo/boot-architecture
> >
>
> --
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Re: RFC: EBBR specification update

2020-03-11 Thread Heinrich Schuchardt

On 3/11/20 12:10 PM, Daniel Thompson wrote:

On Tue, Mar 10, 2020 at 06:34:35PM +0100, Francois Ozog wrote:

On Tue, 10 Mar 2020 at 18:19, Daniel Thompson
wrote:

On Tue, Mar 10, 2020 at 05:02:27PM +0100, Francois Ozog wrote:

0.1 - EBBR goal
May be a reassessment on the "for what" the specification is built.

Maximising number of EBBR compliant systems without stating use case
parameters ( "why" and "for what") may not be the best goal.

We have resisted levels in EBBR until now but this might be where might
have a need for them.

Put another way I agree that getting explicit about mandatory features
for secure boot flows is useful.

However I also think that is remains valuable to define best practice
for how firmware and OS interact on systems that have not implemented
secure boot.

It's all about the target use:

1) industrial (manufacturing, automotive, robotics, medical...) components
2) telecom edge
3) 96boards
4) developer desktop
5) server

As I just consider 1 and 2, I have no case without secure boot...
Now the dev platform can come without the secureboot active and
SElinx deactivated
In what context you think this is usefull?

I would like it to be possible for dev boards and SoMs whose SoCs do not
have a built-in root of trust to have some basic level of EBBR
compliance.

I don't like to optics of saying "this standard cannot possibly apply to
a Raspberry Pi"[1]. Taking the RPi Zero or CM3 as examples[2], I can't see any
value added by secure boot since the root-of-trust would have to start
on the same media as the operating system anyway.

There is a TPMv2 module available for Raspberries.

https://buyzero.de/products/letstrust-hardware-tpm-trusted-platform-module?variant=33890452626

Would we be able to use this as root of trust?

Would we recommend the EFI TPM2 Protocol to be implemented in the EBBR
as a possible source of trust? Daniel Kiper, one of the maintainers of
GRUB, expressed interest in this feature.

https://trustedcomputinggroup.org/wp-content/uploads/EFI-Protocol-Specification-rev13-160330final.pdf

Best regards

Heinrich

Daniel.

[1] I'd also worried about some of the open-market Arm SoMs as well,
but since 96Boards has skin in the game there I've adopted a
less partisan example above.

[2] There are problems with RPi4 too but they are different (and
hopefully less severe).

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Re: RFC: EBBR specification update

On Wed, Mar 11, 2020 at 01:42:36PM +0100, Francois Ozog wrote:
> On Wed, 11 Mar 2020 at 12:45, Daniel Thompson 
> wrote:
> 
> > On Wed, Mar 11, 2020 at 11:20:17AM +0100, Francois Ozog wrote:
> > > On Wed, 11 Mar 2020 at 07:48, Heinrich Schuchardt 
> > wrote:
> > > > On 3/11/20 12:04 AM, Heinrich Schuchardt wrote:
> > > > In the expert mode of gdisk there is command 'j' for moving the GPT
> > > > Partition Entry Array to an arbitrary sector. This will protect the
> > area
> > > > between the GPT header and the GPT Partition Entry Array from being
> > used
> > > > for a partition. The same can be done with parameter -j of sgdisk.
> > > >
> > > > Furthermore gdisk supports creating a hybrid MBR. This allow to have
> > > > GUID partition table and a MBR partion table at the same time where the
> > > > MBR partition table mirrors up to three GPT partitions and the fourth
> > > > MBR partition is used to protect the GUID partition table.
> > > >
> > > > So requiring GPT and having boards only supporting booting from an MBR
> > > > partition (like the Raspberry) seems not to be exclusive.
> > > >
> > >
> > > That sounds like a great solution!
> >
> > The last time we discussed this there was *very* strong opposition
> > during meetings to hybrid partitioning and IIRC language was added to
> > the spec to prohibit it.
> >
> > Hybrid partitioning is a problem because it imposes to difficult to meet
> > constraints on partitioning tools provided by the operating system.
> >
> > In other words if we permit hybrid partitioning in order that boot code
> > can find the firmware then the operating system would inherit a duty to
> > not to screw up the firmware loading when it modifies the partition
> > tables. It is hard to express how the OS should go about that.
> >
> > Hence the current approach where we accept that MBR partitioning
> > offers an inferior feature set to GPT.
> >
> >
> We have the following cases:
> 
> - FW compatible with GPT  (I mean firmware can be searched based on
> GUID partition)
> Ok
> 
> - FW that uses offsets and can be positioned at LBA >= 33
> Ok
> Need to define a protective partition
> 
> - FW that uses offsets and can be positioned such that space between LBA-2
> and LBA-33 is used.
> Ok in theory as the header states where the partition entries location is
> specified in a GPT_HEADER "Starting LBA of array of partition entries".
> Linux kernel properly loads the partition entries if we push them after
> 16MB.
> 
> read_lba (state,
> le64_to_cpu 
> (gpt->partition_entry_lba)
> 
> But I bet 2 is hardcoded in many tools...

Agree... but that's "just bugs" and I suspect we could get >90% test
coverage for Linux systems just by checking util-linux (and the kernel
itself). Maybe for extra style points also check on of the BSDs.


> - FW that supposes LBA-1 (macchiatobin the firmware blob that contain TF-A
> must be here)
> In theory OK as Linux will detect bad signature and use the alternate GPT

In the current spec this case isn't materially different to firmware
whose boot ROM parses the MBR to load extra code (which wasn't listed
above). In both cases the system would be expected to adopt MBR and
create protective partitions for the firmware (and accept that the
protective partition is vulnerable to damage by auto-partitioning
installers).

Having said is this really relevant for MacchiatoBin? Why put EBBR
firmware onto shared media? I thought MacchiatoBin could boot from the
4MB SPI NOR.


Daniel.


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Re: RFC: EBBR specification update

2020-03-11 Thread Heinrich Schuchardt




On 3/11/20 3:20 PM, Francois Ozog wrote:



On Wed, 11 Mar 2020 at 13:42, Francois Ozog mailto:francois.o...@linaro.org>> wrote:



On Wed, 11 Mar 2020 at 12:45, Daniel Thompson
mailto:daniel.thomp...@linaro.org>> wrote:

On Wed, Mar 11, 2020 at 11:20:17AM +0100, Francois Ozog wrote:
 > On Wed, 11 Mar 2020 at 07:48, Heinrich Schuchardt
mailto:xypron.g...@gmx.de>> wrote:
 > > On 3/11/20 12:04 AM, Heinrich Schuchardt wrote:
 > > > On 3/10/20 7:37 PM, Francois Ozog wrote:
 > > >> Le mar. 10 mars 2020 à 18:37, Daniel Thompson
 > > >> mailto:daniel.thomp...@linaro.org>> a écrit :
 > > >>> On Tue, Mar 10, 2020 at 05:35:40PM +0100, Francois Ozog
wrote:
 > >  This is driven by the BL2 which is platform specific
and I am not sure
 > >  we can have any influence.
 > >  The flashimage.bin in a number of system consists of a
(blob) FIP that
 > >  has BL2, SCP stuff, BL31, BL32, BL33.
 > >  Ilias upstream U-Boot patches to change from "ADR" to
"ADRL" because
 > >  the code grew too much.
 > > >>>
 > > >>> I'm not quite sure I understand the concern here.
 > > >>>
 > > >>> Are you still working on systems where the boot ROM
mandates using MBR
 > > >>> partitioning and attempting to put secure boot on it?
If so perhaps we
 > > >>> could simply discontinue MBR support for systems with
secure boot!
 > > >>>
 > > >>
 > > >> Well. we want Products on the market to benefit from
EBBR compliance
 > > >> rather than two years from now. So MBR is inevitable.
And is not that a
 > > >> pain ;-) Of course its not as clean as we would like but
“sales first”!
 > > >
 > > > A typical problem is that a SoC has an entry address
within the first 17
 > > > KiB, e.g. the Allwinner CPUs want a firmware entry point
at 0x2000. If I
 > > > correctly understand the UEFI standard, one might use
PartitionEntryLBA
 > > > to place the GPT Partition Entry Array behind the
firmware in this case.
 > > >
 > >
 > > In the expert mode of gdisk there is command 'j' for moving
the GPT
 > > Partition Entry Array to an arbitrary sector. This will
protect the area
 > > between the GPT header and the GPT Partition Entry Array
from being used
 > > for a partition. The same can be done with parameter -j of
sgdisk.
 > >
 > > Furthermore gdisk supports creating a hybrid MBR. This
allow to have
 > > GUID partition table and a MBR partion table at the same
time where the
 > > MBR partition table mirrors up to three GPT partitions and
the fourth
 > > MBR partition is used to protect the GUID partition table.
 > >
 > > So requiring GPT and having boards only supporting booting
from an MBR
 > > partition (like the Raspberry) seems not to be exclusive.
 > >
 >
 > That sounds like a great solution!

The last time we discussed this there was *very* strong opposition
during meetings to hybrid partitioning and IIRC language was
added to
the spec to prohibit it.

Hybrid partitioning is a problem because it imposes to difficult
to meet
constraints on partitioning tools provided by the operating system.

In other words if we permit hybrid partitioning in order that
boot code
can find the firmware then the operating system would inherit a
duty to
not to screw up the firmware loading when it modifies the partition
tables. It is hard to express how the OS should go about that.

Hence the current approach where we accept that MBR partitioning
offers an inferior feature set to GPT.


We have the following cases:

- FW compatible with GPT  (I mean firmware can be searched based on
GUID partition)
Ok

- FW that uses offsets and can be positioned at LBA >= 33
Ok
Need to define a protective partition

- FW that uses offsets and can be positioned such that space between
LBA-2 and LBA-33 is used.
Ok in theory as the header states where the partition entries
location is specified in a GPT_HEADER "Starting LBA of array of
partition entries".
Linux kernel properly loads the partition entries if we push them
after 16MB.

read_lba (state,  
le64_to_cpu

(gpt->partition_entry_lba)

But I bet 2 is hardcoded in many tools...

If I had done my homework properly, I would have seen that
U-Boot CONFIG_EFI_PARTITION_ENTRIES_

Re: RFC: EBBR specification update

2020-03-11 Thread Francois Ozog

On Wed, 11 Mar 2020 at 07:55, AKASHI Takahiro 
wrote:

> Regarding capsule update,
>
> On Tue, Mar 10, 2020 at 09:45:28PM +0100, Francois Ozog wrote:
> > Le mar. 10 mars 2020 à 21:15, Heinrich Schuchardt  a
> > écrit :
> > > On 3/10/20 5:02 PM, Francois Ozog wrote:
>
> (snip)
>
> > > > VI - UEFI update capsules
> > > > Following my view in 0) I think this shall be made mandatory
> > >
> > > The UEFI specification provides multiple possibilities to update:
> > >
> > > UpdateCapsule() runtime service - This runtime service is quite hard to
> > > implement if there is no storage that is off limits for the operating
> > > system.
> > >
> > We do not favor that. There is no way to trust code that could have been
> > compromised in memory.
>
> I'm not sure of the point here, but UpdateCapsule has ability of
> verifying a capsule file, and so as long as the system is securely
> booted, UpdateCapsule should work as expected. The issue is, as Heinrich
> suggested, that we can't assume an "exclusive" access to the device
> on which firmware resides akin to a problem in SetVariable at runtime.
>

Sorry, my point was not valid. Let's check all cases.

If the storage is accessible from untrusted world:
- single storage for firmware and the OS: we can't orchestrate access to
storage between OS and Firmware.
- dedicated storage for firmware (eMMC for firmware, SSD for OS): exclusive
access can be achieved (not mounted by LInux and no common controller), we
may be able to avoid one boot cycle and do the update directly.

> If the storage is only accessible from TrustZone, the update is conducted
by TrustZone code which has exclusive access to device, so update can
happen at runtime. We don't want to work on this at this stage. And may be
not in the long term: I think this is a vendor opportunity to differentiate
and it feels way too complex to make it generic.

>
> > It would mean doing an update of uboot from OPTEE so
> > it does not look good as only uboot of a platform knows how to update
> > itself.
> >
> > >
> > > Directory \EFI\UpdateCapsule - A file placed on this directory on the
> > > boot device is considered a capsule. This is much easier to implement.
> > >
> > > Essentially you could also use BootNext to run any binary for updating.
> > >
> > > I suggest to go for the directory method of capsule updating.
> > >
> > That’s the goal for the moment. Yet a whole bunch new to be clarified. We
> > are working on a document to be commented.
>
> As some of you may know, I'm going to submit a RFC patch series for UEFI
> capsule support on U-Boot in a week or so (maybe). With this patch,
> we will support "Capsule-on-Disk" only (but without authentication
> implemented).
>
> One of my concerns here is about "variable update via a capsule" as
> an alternative of "SetVariable at runtime," where values to be set
> for variables will be exported as a capsule file and all the updates
> will take place after rebooting. This is very useful on systems
> where SetVariable is not available at runtime for some reasons.
> Some idea has been proposed by Peter[1], but the discussion has been
> stalled for a long time.
>
> [1]
> https://lists.linaro.org/pipermail/boot-architecture/2018-October/000883.html
>
> Thanks,
> -Takahiro Akashi
>
>
> > >
> > > >
> > > > Section 2.6 of UEFI spec 2.7 mentions
> > > > At some point in time we will need to propose UEFI specification
> update
> > > for:
> > > > - anti-bricking anti rollback expected behavior
> > > > - abstract capsules for "start transaction", "commit", "rollback"
> when
> > > > we will be dealing with system wide transactional updates.
> > > > There is probably a lot to state here but I am just starting the
> > > discussion.
> > > >
> > > > VII - UEFI watchdog
> > > > Following my view in 0) I think this shall be made mandatory
> > >
> > > I could imagine the following scenarios where a watchdog is helpful:
> > >
> > > * A/B scenario: this would require a variable to be updated that
> > >switches between A and B
> > > * booting via network (retry)
> > >
> > Yes: would you consider HTTP booting as an option (not in EBBR though but
> > in Uboot)?
> >
> > >
> > > Watchdogs are available both in EDK II and U-Boot.
> > >
> > Problem is that a leading industrial OEM reported inconsistency in
> > implementation and too small (5 minutes) delay . The exact problem yet
> need
> > to be fully described by the vendor so that it be solved.
> >
> > >
> > > Best regards
> > >
> > > Heinrich
> > >
> > > >
> > > > In addition to its definition, it should also integrate consistent
> > > > parameters to define total duration covered as well as number of
> > > > failed consecutive updates to be triggered as well as how it is
> > > > delivered (powercycle, NMI, secureIRQ...)
> > > >
> > > > Cheers
> > > >
> > >
> > > ___
> > > boot-architecture mailing list
> > > boot-architecture@lists.linaro.org
> > > https://lists.linaro.org/mailman/listinfo/boot-arc

Re: RFC: EBBR specification update

On Wed, Mar 11, 2020 at 11:20:17AM +0100, Francois Ozog wrote:
> On Wed, 11 Mar 2020 at 07:48, Heinrich Schuchardt  wrote:
> > On 3/11/20 12:04 AM, Heinrich Schuchardt wrote:
> > > On 3/10/20 7:37 PM, Francois Ozog wrote:
> > >> Le mar. 10 mars 2020 à 18:37, Daniel Thompson
> > >>  a écrit :
> > >>> On Tue, Mar 10, 2020 at 05:35:40PM +0100, Francois Ozog wrote:
> >  This is driven by the BL2 which is platform specific and I am not sure
> >  we can have any influence.
> >  The flashimage.bin in a number of system consists of a (blob) FIP that
> >  has BL2, SCP stuff, BL31, BL32, BL33.
> >  Ilias upstream U-Boot patches to change from "ADR" to "ADRL" because
> >  the code grew too much.
> > >>>
> > >>> I'm not quite sure I understand the concern here.
> > >>>
> > >>> Are you still working on systems where the boot ROM mandates using MBR
> > >>> partitioning and attempting to put secure boot on it? If so perhaps we
> > >>> could simply discontinue MBR support for systems with secure boot!
> > >>>
> > >>
> > >> Well. we want Products on the market to benefit from EBBR compliance
> > >> rather than two years from now. So MBR is inevitable. And is not that a
> > >> pain ;-) Of course its not as clean as we would like but “sales first”!
> > >
> > > A typical problem is that a SoC has an entry address within the first 17
> > > KiB, e.g. the Allwinner CPUs want a firmware entry point at 0x2000. If I
> > > correctly understand the UEFI standard, one might use PartitionEntryLBA
> > > to place the GPT Partition Entry Array behind the firmware in this case.
> > >
> >
> > In the expert mode of gdisk there is command 'j' for moving the GPT
> > Partition Entry Array to an arbitrary sector. This will protect the area
> > between the GPT header and the GPT Partition Entry Array from being used
> > for a partition. The same can be done with parameter -j of sgdisk.
> >
> > Furthermore gdisk supports creating a hybrid MBR. This allow to have
> > GUID partition table and a MBR partion table at the same time where the
> > MBR partition table mirrors up to three GPT partitions and the fourth
> > MBR partition is used to protect the GUID partition table.
> >
> > So requiring GPT and having boards only supporting booting from an MBR
> > partition (like the Raspberry) seems not to be exclusive.
> >
> 
> That sounds like a great solution!

The last time we discussed this there was *very* strong opposition
during meetings to hybrid partitioning and IIRC language was added to
the spec to prohibit it.

Hybrid partitioning is a problem because it imposes to difficult to meet
constraints on partitioning tools provided by the operating system.

In other words if we permit hybrid partitioning in order that boot code
can find the firmware then the operating system would inherit a duty to
not to screw up the firmware loading when it modifies the partition
tables. It is hard to express how the OS should go about that.

Hence the current approach where we accept that MBR partitioning
offers an inferior feature set to GPT.


Daniel.
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Re: RFC: EBBR specification update

On Wed, Mar 11, 2020 at 12:04:45AM +0100, Heinrich Schuchardt wrote:
> > > > > The 1MB was to deal with limitations in the boot rom. If the boot rom
> > > > > needs extra space, would it not be better to have an initial loader
> > > that
> > > > > understands partitioning in the 1st 1MB and load the remaining images
> > > > > from a real partition?
> > > > 
> > > > This is driven by the BL2 which is platform specific and I am not sure
> > > > we can have any influence.
> > > > The flashimage.bin in a number of system consists of a (blob) FIP that
> > > > has BL2, SCP stuff, BL31, BL32, BL33.
> > > > Ilias upstream U-Boot patches to change from "ADR" to "ADRL" because
> > > > the code grew too much.
> > > 
> > > I'm not quite sure I understand the concern here.
> > > 
> > > Are you still working on systems where the boot ROM mandates using MBR
> > > partitioning and attempting to put secure boot on it? If so perhaps we
> > > could simply discontinue MBR support for systems with secure boot!
> > > 
> > 
> > Well. we want Products on the market to benefit from EBBR compliance
> > rather than two years from now. So MBR is inevitable. And is not that a
> > pain ;-) Of course its not as clean as we would like but “sales first”!
> 
> A typical problem is that a SoC has an entry address within the first 17
> KiB, e.g. the Allwinner CPUs want a firmware entry point at 0x2000. If I
> correctly understand the UEFI standard, one might use PartitionEntryLBA
> to place the GPT Partition Entry Array behind the firmware in this case.

Often when you try to get clever with the GPT stuff in the UEFI standard
you find a field that does what you want and then somewhere else a bit a
language that restricts what you can set it too ;-).

However I can't find anything like that for PartitionEntryLBA so this
would certainly make the problem extremely narrow.

1. System boots from shared media

2. System cannot use hardware partitioning features of the shared boot
   media (perhaps it is an SD card or because the boot ROM does
   not try eMMC boot protocol first)

3. Either Boot ROM entry point makes GPT partitioning impossible or
   Boot ROM automatically parses MBR to locate additional boot code
   and therefore needs a real MBR partition.

4. We care that automatic partition tools doesn't know how to avoid
   reallocating space allocated to the firmware (and that manual tools
   can't warn about it).

Given the extremely narrow scope, I'm suggest that requirement #4 does
not exist on any system ;-).

Daniel.
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Re: RFC: EBBR specification update

On Tue, Mar 10, 2020 at 06:34:35PM +0100, Francois Ozog wrote:
> On Tue, 10 Mar 2020 at 18:19, Daniel Thompson 
> wrote:
> 
> > On Tue, Mar 10, 2020 at 05:02:27PM +0100, Francois Ozog wrote:
> > > 0.1 - EBBR goal
> > > May be a reassessment on the "for what" the specification is built.
> > >
> > > Following all the discussions with prominent industry players, I start
> > > to think that limiting the constraints to be EBBR compliant may become
> > > counter productive. There will be both EBBR non compliant and EBBR
> > > compliant systems. This is inevitable. But EBBR exist for a number of
> > > use cases in a number of markets. The value of EBBR is consistent
> > > behavior across those.
> > >
> > > Maximising number of EBBR compliant systems without stating use case
> > > parameters ( "why" and "for what") may not be the best goal.
> > >
> > > Out of things to be more explicit are supported secure boot flows
> > > (with/without shim+grub or direct). Some vendors require shim+grub
> > > while industry players want the exact opposite: nothing but UEFI. This
> > > drivers a number of requirements in terms of UEFI protocols needed
> >
> > We have resisted levels in EBBR until now but this might be where might
> > have a need for them.
> >
> > Put another way I agree that getting explicit about mandatory features
> > for secure boot flows is useful.
> >
> > However I also think that is remains valuable to define best practice
> > for how firmware and OS interact on systems that have not implemented
> > secure boot.
> >
> > It's all about the target use:
> 1) industrial (manufacturing, automotive, robotics, medical...) components
> 2) telecom edge
> 3) 96boards
> 4) developer desktop
> 5) server
> 
> As I just consider 1 and 2, I have no case without secure boot...
> Now the dev platform can come without the secureboot active and
> SElinx deactivated
> In what context you think this is usefull?

I would like it to be possible for dev boards and SoMs whose SoCs do not
have a built-in root of trust to have some basic level of EBBR
compliance.

I don't like to optics of saying "this standard cannot possibly apply to
a Raspberry Pi"[1]. Taking the RPi Zero or CM3 as examples[2], I can't see any
value added by secure boot since the root-of-trust would have to start
on the same media as the operating system anyway.


Daniel.


[1] I'd also worried about some of the open-market Arm SoMs as well,
but since 96Boards has skin in the game there I've adopted a
less partisan example above.

[2] There are problems with RPi4 too but they are different (and
hopefully less severe).

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Re: RFC: EBBR specification update

2020-03-11 Thread Francois Ozog

On Wed, 11 Mar 2020 at 07:48, Heinrich Schuchardt  wrote:
>
> On 3/11/20 12:04 AM, Heinrich Schuchardt wrote:
> > On 3/10/20 7:37 PM, Francois Ozog wrote:
> >> Le mar. 10 mars 2020 à 18:37, Daniel Thompson
> >> 
> >> a écrit :
> >>
> >>> On Tue, Mar 10, 2020 at 05:35:40PM +0100, Francois Ozog wrote:
> >> 0.2 - normative text
> >> The normative section shall be stated clearly: is " 1.2. Guiding
> >> Principles" normative?
> >>
> >> IETF and ETSI have different language conventions to express
> >> absolutely mandated and various levels of optionality. This spec may
> >> be red by Telecom people or Linux people. Their interpretation may be
> >> erroneous on words such as "shall" (ETSI "SHALL" = "IETF "MUST"). The
> >> language need to be explicit.
> >
> > Fair point. Do you have a suggesting on how to proceed here?
> >
> 
>  Thanks Leif for the links. I tend to like the ETSI one because it is
>  somewhat complete on necessary english grammar stuff.
>  But I am flexible, important we state explicitly the reference
>  document and we use the language constructs.
> >>>
> >>> Does ETSI offer us "features" that are missing from RFC 2119.
> >>>
> >>> Personally I would favour RFC 2119 simply because it is so much better
> >>> known than the ETSI drafting rules.
> >>>
> >>> If you cite RFC 2119 and I don't have to go and read anything... and
> >>> even if I did it is super concise and quick to read.
> >>>
> >>> Cite ETSI drafting rules, clause 3 and I have to put in a lot more
> >>> effort.
> >>>
> 
> >> I - protective offsets
> >> EBBR 1.0 states in "4.1. Partitioning of Shared Storage" that
> >> "Automatic partitioning tools (e.g. an OS installer) must not create
> >> partitions within the first 1MiB of storage, or delete, move, or
> >> modify protective partition entries."
> >>
> >> StandaloneMM is 2.5MB by itself with U-Boot being over 1MB without
> >>> the
> >> variable rework done and update capsules. 4MB seems the minimum. 8MB
> >> to get margin and 16MB for A/B scheme.
> >
> > The 1MB was to deal with limitations in the boot rom. If the boot rom
> > needs extra space, would it not be better to have an initial loader
> >>> that
> > understands partitioning in the 1st 1MB and load the remaining images
> > from a real partition?
> 
>  This is driven by the BL2 which is platform specific and I am not sure
>  we can have any influence.
>  The flashimage.bin in a number of system consists of a (blob) FIP that
>  has BL2, SCP stuff, BL31, BL32, BL33.
>  Ilias upstream U-Boot patches to change from "ADR" to "ADRL" because
>  the code grew too much.
> >>>
> >>> I'm not quite sure I understand the concern here.
> >>>
> >>> Are you still working on systems where the boot ROM mandates using MBR
> >>> partitioning and attempting to put secure boot on it? If so perhaps we
> >>> could simply discontinue MBR support for systems with secure boot!
> >>>
> >>
> >> Well. we want Products on the market to benefit from EBBR compliance
> >> rather than two years from now. So MBR is inevitable. And is not that a
> >> pain ;-) Of course its not as clean as we would like but “sales first”!
> >
> > A typical problem is that a SoC has an entry address within the first 17
> > KiB, e.g. the Allwinner CPUs want a firmware entry point at 0x2000. If I
> > correctly understand the UEFI standard, one might use PartitionEntryLBA
> > to place the GPT Partition Entry Array behind the firmware in this case.
> >
>
> In the expert mode of gdisk there is command 'j' for moving the GPT
> Partition Entry Array to an arbitrary sector. This will protect the area
> between the GPT header and the GPT Partition Entry Array from being used
> for a partition. The same can be done with parameter -j of sgdisk.
>
> Furthermore gdisk supports creating a hybrid MBR. This allow to have
> GUID partition table and a MBR partion table at the same time where the
> MBR partition table mirrors up to three GPT partitions and the fourth
> MBR partition is used to protect the GUID partition table.
>
> So requiring GPT and having boards only supporting booting from an MBR
> partition (like the Raspberry) seems not to be exclusive.
>

That sounds like a great solution!

> Best regards
>
> Heinrich
>
> >
> >>
> >>>
> >>> In all other cases a bulky firmware installed on shared media must have
> >>> a protective partition (with the appropriate flags) to prevent partition
> >>> tools from damaging it anyway. In such a case it does not matter if
> >>> there is firmware above the 1MB boundary.
> >>>
> >>>
> >> EBBR same paragraph also states:
> >> "Automatic partitioning tools (e.g. an OS installer) must not create
> >> partitions within the first 1MiB of storage, or delete, move, or
> >> modify protective partition entries. Manual partitioning tools should
> >> provide warnings when modifying protective

Re: RFC: EBBR specification update

2020-03-10 Thread AKASHI Takahiro

Regarding capsule update,

On Tue, Mar 10, 2020 at 09:45:28PM +0100, Francois Ozog wrote:
> Le mar. 10 mars 2020 à 21:15, Heinrich Schuchardt  a
> écrit :
> > On 3/10/20 5:02 PM, Francois Ozog wrote:

(snip)

> > > VI - UEFI update capsules
> > > Following my view in 0) I think this shall be made mandatory
> >
> > The UEFI specification provides multiple possibilities to update:
> >
> > UpdateCapsule() runtime service - This runtime service is quite hard to
> > implement if there is no storage that is off limits for the operating
> > system.
> >
> We do not favor that. There is no way to trust code that could have been
> compromised in memory.

I'm not sure of the point here, but UpdateCapsule has ability of
verifying a capsule file, and so as long as the system is securely
booted, UpdateCapsule should work as expected. The issue is, as Heinrich
suggested, that we can't assume an "exclusive" access to the device
on which firmware resides akin to a problem in SetVariable at runtime.

> It would mean doing an update of uboot from OPTEE so
> it does not look good as only uboot of a platform knows how to update
> itself.
> 
> >
> > Directory \EFI\UpdateCapsule - A file placed on this directory on the
> > boot device is considered a capsule. This is much easier to implement.
> >
> > Essentially you could also use BootNext to run any binary for updating.
> >
> > I suggest to go for the directory method of capsule updating.
> >
> That’s the goal for the moment. Yet a whole bunch new to be clarified. We
> are working on a document to be commented.

As some of you may know, I'm going to submit a RFC patch series for UEFI
capsule support on U-Boot in a week or so (maybe). With this patch,
we will support "Capsule-on-Disk" only (but without authentication
implemented).

One of my concerns here is about "variable update via a capsule" as
an alternative of "SetVariable at runtime," where values to be set
for variables will be exported as a capsule file and all the updates
will take place after rebooting. This is very useful on systems
where SetVariable is not available at runtime for some reasons.
Some idea has been proposed by Peter[1], but the discussion has been
stalled for a long time.

[1] 
https://lists.linaro.org/pipermail/boot-architecture/2018-October/000883.html

Thanks,
-Takahiro Akashi


> >
> > >
> > > Section 2.6 of UEFI spec 2.7 mentions
> > > At some point in time we will need to propose UEFI specification update
> > for:
> > > - anti-bricking anti rollback expected behavior
> > > - abstract capsules for "start transaction", "commit", "rollback" when
> > > we will be dealing with system wide transactional updates.
> > > There is probably a lot to state here but I am just starting the
> > discussion.
> > >
> > > VII - UEFI watchdog
> > > Following my view in 0) I think this shall be made mandatory
> >
> > I could imagine the following scenarios where a watchdog is helpful:
> >
> > * A/B scenario: this would require a variable to be updated that
> >switches between A and B
> > * booting via network (retry)
> >
> Yes: would you consider HTTP booting as an option (not in EBBR though but
> in Uboot)?
> 
> >
> > Watchdogs are available both in EDK II and U-Boot.
> >
> Problem is that a leading industrial OEM reported inconsistency in
> implementation and too small (5 minutes) delay . The exact problem yet need
> to be fully described by the vendor so that it be solved.
> 
> >
> > Best regards
> >
> > Heinrich
> >
> > >
> > > In addition to its definition, it should also integrate consistent
> > > parameters to define total duration covered as well as number of
> > > failed consecutive updates to be triggered as well as how it is
> > > delivered (powercycle, NMI, secureIRQ...)
> > >
> > > Cheers
> > >
> >
> > ___
> > boot-architecture mailing list
> > boot-architecture@lists.linaro.org
> > https://lists.linaro.org/mailman/listinfo/boot-architecture
> >
> -- 
> François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
> T: +33.67221.6485
> francois.o...@linaro.org | Skype: ffozog
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Re: RFC: EBBR specification update


On 3/11/20 12:04 AM, Heinrich Schuchardt wrote:

On 3/10/20 7:37 PM, Francois Ozog wrote:

Le mar. 10 mars 2020 à 18:37, Daniel Thompson

a écrit :


On Tue, Mar 10, 2020 at 05:35:40PM +0100, Francois Ozog wrote:

0.2 - normative text
The normative section shall be stated clearly: is " 1.2. Guiding
Principles" normative?

IETF and ETSI have different language conventions to express
absolutely mandated and various levels of optionality. This spec may
be red by Telecom people or Linux people. Their interpretation may be
erroneous on words such as "shall" (ETSI "SHALL" = "IETF "MUST"). The
language need to be explicit.


Fair point. Do you have a suggesting on how to proceed here?



Thanks Leif for the links. I tend to like the ETSI one because it is
somewhat complete on necessary english grammar stuff.
But I am flexible, important we state explicitly the reference
document and we use the language constructs.


Does ETSI offer us "features" that are missing from RFC 2119.

Personally I would favour RFC 2119 simply because it is so much better
known than the ETSI drafting rules.

If you cite RFC 2119 and I don't have to go and read anything... and
even if I did it is super concise and quick to read.

Cite ETSI drafting rules, clause 3 and I have to put in a lot more
effort.




I - protective offsets
EBBR 1.0 states in "4.1. Partitioning of Shared Storage" that
"Automatic partitioning tools (e.g. an OS installer) must not create
partitions within the first 1MiB of storage, or delete, move, or
modify protective partition entries."

StandaloneMM is 2.5MB by itself with U-Boot being over 1MB without

the

variable rework done and update capsules. 4MB seems the minimum. 8MB
to get margin and 16MB for A/B scheme.


The 1MB was to deal with limitations in the boot rom. If the boot rom
needs extra space, would it not be better to have an initial loader

that

understands partitioning in the 1st 1MB and load the remaining images
from a real partition?


This is driven by the BL2 which is platform specific and I am not sure
we can have any influence.
The flashimage.bin in a number of system consists of a (blob) FIP that
has BL2, SCP stuff, BL31, BL32, BL33.
Ilias upstream U-Boot patches to change from "ADR" to "ADRL" because
the code grew too much.


I'm not quite sure I understand the concern here.

Are you still working on systems where the boot ROM mandates using MBR
partitioning and attempting to put secure boot on it? If so perhaps we
could simply discontinue MBR support for systems with secure boot!



Well. we want Products on the market to benefit from EBBR compliance
rather than two years from now. So MBR is inevitable. And is not that a
pain ;-) Of course its not as clean as we would like but “sales first”!


A typical problem is that a SoC has an entry address within the first 17
KiB, e.g. the Allwinner CPUs want a firmware entry point at 0x2000. If I
correctly understand the UEFI standard, one might use PartitionEntryLBA
to place the GPT Partition Entry Array behind the firmware in this case.



In the expert mode of gdisk there is command 'j' for moving the GPT
Partition Entry Array to an arbitrary sector. This will protect the area
between the GPT header and the GPT Partition Entry Array from being used
for a partition. The same can be done with parameter -j of sgdisk.

Furthermore gdisk supports creating a hybrid MBR. This allow to have
GUID partition table and a MBR partion table at the same time where the
MBR partition table mirrors up to three GPT partitions and the fourth
MBR partition is used to protect the GUID partition table.

So requiring GPT and having boards only supporting booting from an MBR
partition (like the Raspberry) seems not to be exclusive.

Best regards

Heinrich







In all other cases a bulky firmware installed on shared media must have
a protective partition (with the appropriate flags) to prevent partition
tools from damaging it anyway. In such a case it does not matter if
there is firmware above the 1MB boundary.



EBBR same paragraph also states:
"Automatic partitioning tools (e.g. an OS installer) must not create
partitions within the first 1MiB of storage, or delete, move, or
modify protective partition entries. Manual partitioning tools should
provide warnings when modifying protective partitions or creating
partitions within the first 1MiB."

is it expected that Linaro upstreams changes in installation tools,
partition tools to conform to this (with updated to be agreed
minimum)?


I would expect so, if they aren't already doing that.


Will need to create initiatives for that.


Pretty much all tools already respect the 1MiB boundary. Sometimes they
use an "expert mode" rather than a explicit warning but I'd view that
as equivalent.


Daniel.





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Re: RFC: EBBR specification update


On 3/10/20 7:37 PM, Francois Ozog wrote:

Le mar. 10 mars 2020 à 18:37, Daniel Thompson 
a écrit :


On Tue, Mar 10, 2020 at 05:35:40PM +0100, Francois Ozog wrote:

0.2 - normative text
The normative section shall be stated clearly: is " 1.2. Guiding
Principles" normative?

IETF and ETSI have different language conventions to express
absolutely mandated and various levels of optionality. This spec may
be red by Telecom people or Linux people. Their interpretation may be
erroneous on words such as "shall" (ETSI "SHALL" = "IETF "MUST"). The
language need to be explicit.


Fair point. Do you have a suggesting on how to proceed here?



Thanks Leif for the links. I tend to like the ETSI one because it is
somewhat complete on necessary english grammar stuff.
But I am flexible, important we state explicitly the reference
document and we use the language constructs.


Does ETSI offer us "features" that are missing from RFC 2119.

Personally I would favour RFC 2119 simply because it is so much better
known than the ETSI drafting rules.

If you cite RFC 2119 and I don't have to go and read anything... and
even if I did it is super concise and quick to read.

Cite ETSI drafting rules, clause 3 and I have to put in a lot more
effort.




I - protective offsets
EBBR 1.0 states in "4.1. Partitioning of Shared Storage" that
"Automatic partitioning tools (e.g. an OS installer) must not create
partitions within the first 1MiB of storage, or delete, move, or
modify protective partition entries."

StandaloneMM is 2.5MB by itself with U-Boot being over 1MB without

the

variable rework done and update capsules. 4MB seems the minimum. 8MB
to get margin and 16MB for A/B scheme.


The 1MB was to deal with limitations in the boot rom. If the boot rom
needs extra space, would it not be better to have an initial loader

that

understands partitioning in the 1st 1MB and load the remaining images
from a real partition?


This is driven by the BL2 which is platform specific and I am not sure
we can have any influence.
The flashimage.bin in a number of system consists of a (blob) FIP that
has BL2, SCP stuff, BL31, BL32, BL33.
Ilias upstream U-Boot patches to change from "ADR" to "ADRL" because
the code grew too much.


I'm not quite sure I understand the concern here.

Are you still working on systems where the boot ROM mandates using MBR
partitioning and attempting to put secure boot on it? If so perhaps we
could simply discontinue MBR support for systems with secure boot!



Well. we want Products on the market to benefit from EBBR compliance
rather than two years from now. So MBR is inevitable. And is not that a
pain ;-) Of course its not as clean as we would like but “sales first”!


A typical problem is that a SoC has an entry address within the first 17
KiB, e.g. the Allwinner CPUs want a firmware entry point at 0x2000. If I
correctly understand the UEFI standard, one might use PartitionEntryLBA
to place the GPT Partition Entry Array behind the firmware in this case.

Best regards

Heinrich





In all other cases a bulky firmware installed on shared media must have
a protective partition (with the appropriate flags) to prevent partition
tools from damaging it anyway. In such a case it does not matter if
there is firmware above the 1MB boundary.



EBBR same paragraph also states:
"Automatic partitioning tools (e.g. an OS installer) must not create
partitions within the first 1MiB of storage, or delete, move, or
modify protective partition entries. Manual partitioning tools should
provide warnings when modifying protective partitions or creating
partitions within the first 1MiB."

is it expected that Linaro upstreams changes in installation tools,
partition tools to conform to this (with updated to be agreed
minimum)?


I would expect so, if they aren't already doing that.


Will need to create initiatives for that.


Pretty much all tools already respect the 1MiB boundary. Sometimes they
use an "expert mode" rather than a explicit warning but I'd view that
as equivalent.


Daniel.



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Re: RFC: EBBR specification update


On 3/10/20 9:45 PM, Francois Ozog wrote:

Le mar. 10 mars 2020 à 21:15, Heinrich Schuchardt  a
écrit :


On 3/10/20 5:02 PM, Francois Ozog wrote:

Hi,

Following implementation (or work towards) of EBBR 1.0 + UEFI Secure
boot + UEFI update capsule we learnt a lot.

Here are some topics that may need some clarification on the EBBR
specs and It looks timely to start working on EBBR evolution.

0.1 - EBBR goal
May be a reassessment on the "for what" the specification is built.


EBBR 1.0 is quite vague about this point.

Implementing the requirements of version 1.0 was enough to allow systems
to be booted in a common way. Secure boot is not supported by what is
required.



Following all the discussions with prominent industry players, I start
to think that limiting the constraints to be EBBR compliant may become
counter productive. There will be both EBBR non compliant and EBBR
compliant systems. This is inevitable. But EBBR exist for a number of
use cases in a number of markets. The value of EBBR is consistent
behavior across those.

Maximising number of EBBR compliant systems without stating use case
parameters ( "why" and "for what") may not be the best goal.

Out of things to be more explicit are supported secure boot flows
(with/without shim+grub or direct). Some vendors require shim+grub
while industry players want the exact opposite: nothing but UEFI. This
drivers a number of requirements in terms of UEFI protocols needed


Shim and GRUB are optional tools which operating systems like BSD, Linux
or Windows do not need for booting. I think the EBBR should be operating
system agnostic.



Absolutely.




This does not deny the usefulness of some of these tools. My personal
favorite is booting via U-Boot -> iPXE -> GRUB -> Linux from an iSCSI
drive ;)





0.2 - normative text
The normative section shall be stated clearly: is " 1.2. Guiding
Principles" normative?

IETF and ETSI have different language conventions to express
absolutely mandated and various levels of optionality. This spec may
be red by Telecom people or Linux people. Their interpretation may be
erroneous on words such as "shall" (ETSI "SHALL" = "IETF "MUST"). The
language need to be explicit.


A reference to RFC 2119 should be added to the EBBR.



I - protective offsets
EBBR 1.0 states in "4.1. Partitioning of Shared Storage" that
"Automatic partitioning tools (e.g. an OS installer) must not create
partitions within the first 1MiB of storage, or delete, move, or
modify protective partition entries."

StandaloneMM is 2.5MB by itself with U-Boot being over 1MB without the
variable rework done and update capsules. 4MB seems the minimum. 8MB
to get margin and 16MB for A/B scheme.

EBBR same paragraph also states:
"Automatic partitioning tools (e.g. an OS installer) must not create
partitions within the first 1MiB of storage, or delete, move, or
modify protective partition entries. Manual partitioning tools should
provide warnings when modifying protective partitions or creating
partitions within the first 1MiB."

is it expected that Linaro upstreams changes in installation tools,
partition tools to conform to this (with updated to be agreed
minimum)?


Obviously the minimum required space depends on the firmware and the
maximum depends on the hardware (some devices like routers simply only
have 16MiB flash for firmware and operating system in total).





Shouldn't the firmware have a way to tell the OS how much space it wants
instead of prescribing a fixed quantity?


probably a good idea. It’s never good to take margin of margin (16MB) to
end up being cornered a few years later.






II - identifying partitions
Having two EFI partitions defined with EFI_GUID need a precise
behaviour defined: boot with first or boot with second.


This is only relevant when relying on the \EFI\BOOT directory. If
Boot variables are defined, these specify the relevant partition.



Shall we have a EFI_GUID_ALT defined for A/B partition schemes?
If not, the BootXXX variables should be used as selector?
We lean towards BootXXX variables and not defining a new GUID. But
this would mean explicit behavior to be stated in case of lack of
BootXXX.

I think GPT volume mirroring should be used in conjunction with A/B:
A/B to recover version failures with current hardware, surrounding
software; mirroring to protect against storage failures.

Is there any recommendation on mirrored EFI volumes handling ?


Isn't the availability of Boot variables enough?


I think so. There is a forming thinking that when we commit a partition for
successful update the other is “synchronized”.

That said mirroring in UEFI is a block mirroring between two physical disk
(is it software RAID1?) so both A/B and RAID1 can be combined . But I don’t
know what shall be uboot behavior here.






III - 32 bits
are there any 32 bits specific considerations to be added?


The only thing 32bit specific that comes to my mind is clearing
architecture specific caches as defined in the UEFI

Re: RFC: EBBR specification update

Le mar. 10 mars 2020 à 21:15, Heinrich Schuchardt  a
écrit :

> On 3/10/20 5:02 PM, Francois Ozog wrote:
> > Hi,
> >
> > Following implementation (or work towards) of EBBR 1.0 + UEFI Secure
> > boot + UEFI update capsule we learnt a lot.
> >
> > Here are some topics that may need some clarification on the EBBR
> > specs and It looks timely to start working on EBBR evolution.
> >
> > 0.1 - EBBR goal
> > May be a reassessment on the "for what" the specification is built.
>
> EBBR 1.0 is quite vague about this point.
>
> Implementing the requirements of version 1.0 was enough to allow systems
> to be booted in a common way. Secure boot is not supported by what is
> required.
>
> >
> > Following all the discussions with prominent industry players, I start
> > to think that limiting the constraints to be EBBR compliant may become
> > counter productive. There will be both EBBR non compliant and EBBR
> > compliant systems. This is inevitable. But EBBR exist for a number of
> > use cases in a number of markets. The value of EBBR is consistent
> > behavior across those.
> >
> > Maximising number of EBBR compliant systems without stating use case
> > parameters ( "why" and "for what") may not be the best goal.
> >
> > Out of things to be more explicit are supported secure boot flows
> > (with/without shim+grub or direct). Some vendors require shim+grub
> > while industry players want the exact opposite: nothing but UEFI. This
> > drivers a number of requirements in terms of UEFI protocols needed
>
> Shim and GRUB are optional tools which operating systems like BSD, Linux
> or Windows do not need for booting. I think the EBBR should be operating
> system agnostic.


Absolutely.

>
>
> This does not deny the usefulness of some of these tools. My personal
> favorite is booting via U-Boot -> iPXE -> GRUB -> Linux from an iSCSI
> drive ;)


> >
> > 0.2 - normative text
> > The normative section shall be stated clearly: is " 1.2. Guiding
> > Principles" normative?
> >
> > IETF and ETSI have different language conventions to express
> > absolutely mandated and various levels of optionality. This spec may
> > be red by Telecom people or Linux people. Their interpretation may be
> > erroneous on words such as "shall" (ETSI "SHALL" = "IETF "MUST"). The
> > language need to be explicit.
>
> A reference to RFC 2119 should be added to the EBBR.
>
> >
> > I - protective offsets
> > EBBR 1.0 states in "4.1. Partitioning of Shared Storage" that
> > "Automatic partitioning tools (e.g. an OS installer) must not create
> > partitions within the first 1MiB of storage, or delete, move, or
> > modify protective partition entries."
> >
> > StandaloneMM is 2.5MB by itself with U-Boot being over 1MB without the
> > variable rework done and update capsules. 4MB seems the minimum. 8MB
> > to get margin and 16MB for A/B scheme.
> >
> > EBBR same paragraph also states:
> > "Automatic partitioning tools (e.g. an OS installer) must not create
> > partitions within the first 1MiB of storage, or delete, move, or
> > modify protective partition entries. Manual partitioning tools should
> > provide warnings when modifying protective partitions or creating
> > partitions within the first 1MiB."
> >
> > is it expected that Linaro upstreams changes in installation tools,
> > partition tools to conform to this (with updated to be agreed
> > minimum)?
>
> Obviously the minimum required space depends on the firmware and the
> maximum depends on the hardware (some devices like routers simply only
> have 16MiB flash for firmware and operating system in total).


>
> Shouldn't the firmware have a way to tell the OS how much space it wants
> instead of prescribing a fixed quantity?

probably a good idea. It’s never good to take margin of margin (16MB) to
end up being cornered a few years later.


>
> >
> > II - identifying partitions
> > Having two EFI partitions defined with EFI_GUID need a precise
> > behaviour defined: boot with first or boot with second.
>
> This is only relevant when relying on the \EFI\BOOT directory. If
> Boot variables are defined, these specify the relevant partition.
>
> >
> > Shall we have a EFI_GUID_ALT defined for A/B partition schemes?
> > If not, the BootXXX variables should be used as selector?
> > We lean towards BootXXX variables and not defining a new GUID. But
> > this would mean explicit behavior to be stated in case of lack of
> > BootXXX.
> >
> > I think GPT volume mirroring should be used in conjunction with A/B:
> > A/B to recover version failures with current hardware, surrounding
> > software; mirroring to protect against storage failures.
> >
> > Is there any recommendation on mirrored EFI volumes handling ?
>
> Isn't the availability of Boot variables enough?

I think so. There is a forming thinking that when we commit a partition for
successful update the other is “synchronized”.

That said mirroring in UEFI is a block mirroring between two physical disk
(is it software RAID1?) so both A/B and RAID1 can b

Re: RFC: EBBR specification update


On 3/10/20 5:02 PM, Francois Ozog wrote:

Hi,

Following implementation (or work towards) of EBBR 1.0 + UEFI Secure
boot + UEFI update capsule we learnt a lot.

Here are some topics that may need some clarification on the EBBR
specs and It looks timely to start working on EBBR evolution.

0.1 - EBBR goal
May be a reassessment on the "for what" the specification is built.


EBBR 1.0 is quite vague about this point.

Implementing the requirements of version 1.0 was enough to allow systems
to be booted in a common way. Secure boot is not supported by what is
required.



Following all the discussions with prominent industry players, I start
to think that limiting the constraints to be EBBR compliant may become
counter productive. There will be both EBBR non compliant and EBBR
compliant systems. This is inevitable. But EBBR exist for a number of
use cases in a number of markets. The value of EBBR is consistent
behavior across those.

Maximising number of EBBR compliant systems without stating use case
parameters ( "why" and "for what") may not be the best goal.

Out of things to be more explicit are supported secure boot flows
(with/without shim+grub or direct). Some vendors require shim+grub
while industry players want the exact opposite: nothing but UEFI. This
drivers a number of requirements in terms of UEFI protocols needed


Shim and GRUB are optional tools which operating systems like BSD, Linux
or Windows do not need for booting. I think the EBBR should be operating
system agnostic.

This does not deny the usefulness of some of these tools. My personal
favorite is booting via U-Boot -> iPXE -> GRUB -> Linux from an iSCSI
drive ;)



0.2 - normative text
The normative section shall be stated clearly: is " 1.2. Guiding
Principles" normative?

IETF and ETSI have different language conventions to express
absolutely mandated and various levels of optionality. This spec may
be red by Telecom people or Linux people. Their interpretation may be
erroneous on words such as "shall" (ETSI "SHALL" = "IETF "MUST"). The
language need to be explicit.


A reference to RFC 2119 should be added to the EBBR.



I - protective offsets
EBBR 1.0 states in "4.1. Partitioning of Shared Storage" that
"Automatic partitioning tools (e.g. an OS installer) must not create
partitions within the first 1MiB of storage, or delete, move, or
modify protective partition entries."

StandaloneMM is 2.5MB by itself with U-Boot being over 1MB without the
variable rework done and update capsules. 4MB seems the minimum. 8MB
to get margin and 16MB for A/B scheme.

EBBR same paragraph also states:
"Automatic partitioning tools (e.g. an OS installer) must not create
partitions within the first 1MiB of storage, or delete, move, or
modify protective partition entries. Manual partitioning tools should
provide warnings when modifying protective partitions or creating
partitions within the first 1MiB."

is it expected that Linaro upstreams changes in installation tools,
partition tools to conform to this (with updated to be agreed
minimum)?


Obviously the minimum required space depends on the firmware and the
maximum depends on the hardware (some devices like routers simply only
have 16MiB flash for firmware and operating system in total).

Shouldn't the firmware have a way to tell the OS how much space it wants
instead of prescribing a fixed quantity?



II - identifying partitions
Having two EFI partitions defined with EFI_GUID need a precise
behaviour defined: boot with first or boot with second.


This is only relevant when relying on the \EFI\BOOT directory. If
Boot variables are defined, these specify the relevant partition.



Shall we have a EFI_GUID_ALT defined for A/B partition schemes?
If not, the BootXXX variables should be used as selector?
We lean towards BootXXX variables and not defining a new GUID. But
this would mean explicit behavior to be stated in case of lack of
BootXXX.

I think GPT volume mirroring should be used in conjunction with A/B:
A/B to recover version failures with current hardware, surrounding
software; mirroring to protect against storage failures.

Is there any recommendation on mirrored EFI volumes handling ?


Isn't the availability of Boot variables enough?



III - 32 bits
are there any 32 bits specific considerations to be added?


The only thing 32bit specific that comes to my mind is clearing
architecture specific caches as defined in the UEFI spec.

For RISC-V there is a development ongoing for communicating the boot
hart ID form the firmware to the operating system.



IV - UEFI_RNG_PROTOCOL
Following my view in 0) I think this shall be made mandatory


EBBR v1.0 has as design goal: 'Design for common embedded target'.
"Generally anything that has a near near-upstream U-Boot implementation
should be able to implement the EBBR requirements."

Not all common SoCs have a hardware RNG, e.g. Allwinner (cf.
https://linux-sunxi.org/Cryptographic_Hardware_Accelerators).

I would not assume that enough entro

Re: RFC: EBBR specification update

Le mar. 10 mars 2020 à 18:46, Mark Brown  a écrit :

> On Tue, Mar 10, 2020 at 05:37:29PM +, Daniel Thompson wrote:
> > On Tue, Mar 10, 2020 at 05:35:40PM +0100, Francois Ozog wrote:
>
> > > Thanks Leif for the links. I tend to like the ETSI one because it is
> > > somewhat complete on necessary english grammar stuff.
> > > But I am flexible, important we state explicitly the reference
> > > document and we use the language constructs.
>
> > Does ETSI offer us "features" that are missing from RFC 2119.
>
> > Personally I would favour RFC 2119 simply because it is so much better
> > known than the ETSI drafting rules.
>
> > If you cite RFC 2119 and I don't have to go and read anything... and
> > even if I did it is super concise and quick to read.
>
> > Cite ETSI drafting rules, clause 3 and I have to put in a lot more
> > effort.
>
> The RFC 2119 usage of "MUST" is also a more standard English usage (in
> that people are more likely to be familiar with it) than the ETSI SHALL
> so there's a bit of a comprehensibility win.

RFC2119 sold on my side ;-)

>
> --
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.o...@linaro.org | Skype: ffozog
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Re: RFC: EBBR specification update

Le mar. 10 mars 2020 à 18:37, Daniel Thompson 
a écrit :

> On Tue, Mar 10, 2020 at 05:35:40PM +0100, Francois Ozog wrote:
> > > > 0.2 - normative text
> > > > The normative section shall be stated clearly: is " 1.2. Guiding
> > > > Principles" normative?
> > > >
> > > > IETF and ETSI have different language conventions to express
> > > > absolutely mandated and various levels of optionality. This spec may
> > > > be red by Telecom people or Linux people. Their interpretation may be
> > > > erroneous on words such as "shall" (ETSI "SHALL" = "IETF "MUST"). The
> > > > language need to be explicit.
> > >
> > > Fair point. Do you have a suggesting on how to proceed here?
> > >
> >
> > Thanks Leif for the links. I tend to like the ETSI one because it is
> > somewhat complete on necessary english grammar stuff.
> > But I am flexible, important we state explicitly the reference
> > document and we use the language constructs.
>
> Does ETSI offer us "features" that are missing from RFC 2119.
>
> Personally I would favour RFC 2119 simply because it is so much better
> known than the ETSI drafting rules.
>
> If you cite RFC 2119 and I don't have to go and read anything... and
> even if I did it is super concise and quick to read.
>
> Cite ETSI drafting rules, clause 3 and I have to put in a lot more
> effort.
>
> >
> > > > I - protective offsets
> > > > EBBR 1.0 states in "4.1. Partitioning of Shared Storage" that
> > > > "Automatic partitioning tools (e.g. an OS installer) must not create
> > > > partitions within the first 1MiB of storage, or delete, move, or
> > > > modify protective partition entries."
> > > >
> > > > StandaloneMM is 2.5MB by itself with U-Boot being over 1MB without
> the
> > > > variable rework done and update capsules. 4MB seems the minimum. 8MB
> > > > to get margin and 16MB for A/B scheme.
> > >
> > > The 1MB was to deal with limitations in the boot rom. If the boot rom
> > > needs extra space, would it not be better to have an initial loader
> that
> > > understands partitioning in the 1st 1MB and load the remaining images
> > > from a real partition?
> >
> > This is driven by the BL2 which is platform specific and I am not sure
> > we can have any influence.
> > The flashimage.bin in a number of system consists of a (blob) FIP that
> > has BL2, SCP stuff, BL31, BL32, BL33.
> > Ilias upstream U-Boot patches to change from "ADR" to "ADRL" because
> > the code grew too much.
>
> I'm not quite sure I understand the concern here.
>
> Are you still working on systems where the boot ROM mandates using MBR
> partitioning and attempting to put secure boot on it? If so perhaps we
> could simply discontinue MBR support for systems with secure boot!
>

Well. we want Products on the market to benefit from EBBR compliance
rather than two years from now. So MBR is inevitable. And is not that a
pain ;-) Of course its not as clean as we would like but “sales first”!

>
> In all other cases a bulky firmware installed on shared media must have
> a protective partition (with the appropriate flags) to prevent partition
> tools from damaging it anyway. In such a case it does not matter if
> there is firmware above the 1MB boundary.
>
>
> > > > EBBR same paragraph also states:
> > > > "Automatic partitioning tools (e.g. an OS installer) must not create
> > > > partitions within the first 1MiB of storage, or delete, move, or
> > > > modify protective partition entries. Manual partitioning tools should
> > > > provide warnings when modifying protective partitions or creating
> > > > partitions within the first 1MiB."
> > > >
> > > > is it expected that Linaro upstreams changes in installation tools,
> > > > partition tools to conform to this (with updated to be agreed
> > > > minimum)?
> > >
> > > I would expect so, if they aren't already doing that.
> >
> > Will need to create initiatives for that.
>
> Pretty much all tools already respect the 1MiB boundary. Sometimes they
> use an "expert mode" rather than a explicit warning but I'd view that
> as equivalent.
>
>
> Daniel.
>
-- 
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.o...@linaro.org | Skype: ffozog
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Re: RFC: EBBR specification update

2020-03-10 Thread Daniel Thompson

On Tue, Mar 10, 2020 at 05:35:40PM +0100, Francois Ozog wrote:
> > > 0.2 - normative text
> > > The normative section shall be stated clearly: is " 1.2. Guiding
> > > Principles" normative?
> > >
> > > IETF and ETSI have different language conventions to express
> > > absolutely mandated and various levels of optionality. This spec may
> > > be red by Telecom people or Linux people. Their interpretation may be
> > > erroneous on words such as "shall" (ETSI "SHALL" = "IETF "MUST"). The
> > > language need to be explicit.
> >
> > Fair point. Do you have a suggesting on how to proceed here?
> >
> 
> Thanks Leif for the links. I tend to like the ETSI one because it is
> somewhat complete on necessary english grammar stuff.
> But I am flexible, important we state explicitly the reference
> document and we use the language constructs.

Does ETSI offer us "features" that are missing from RFC 2119.

Personally I would favour RFC 2119 simply because it is so much better
known than the ETSI drafting rules.

If you cite RFC 2119 and I don't have to go and read anything... and
even if I did it is super concise and quick to read.

Cite ETSI drafting rules, clause 3 and I have to put in a lot more
effort.

> 
> > > I - protective offsets
> > > EBBR 1.0 states in "4.1. Partitioning of Shared Storage" that
> > > "Automatic partitioning tools (e.g. an OS installer) must not create
> > > partitions within the first 1MiB of storage, or delete, move, or
> > > modify protective partition entries."
> > >
> > > StandaloneMM is 2.5MB by itself with U-Boot being over 1MB without the
> > > variable rework done and update capsules. 4MB seems the minimum. 8MB
> > > to get margin and 16MB for A/B scheme.
> >
> > The 1MB was to deal with limitations in the boot rom. If the boot rom
> > needs extra space, would it not be better to have an initial loader that
> > understands partitioning in the 1st 1MB and load the remaining images
> > from a real partition?
> 
> This is driven by the BL2 which is platform specific and I am not sure
> we can have any influence.
> The flashimage.bin in a number of system consists of a (blob) FIP that
> has BL2, SCP stuff, BL31, BL32, BL33.
> Ilias upstream U-Boot patches to change from "ADR" to "ADRL" because
> the code grew too much.

I'm not quite sure I understand the concern here.

Are you still working on systems where the boot ROM mandates using MBR
partitioning and attempting to put secure boot on it? If so perhaps we
could simply discontinue MBR support for systems with secure boot!

In all other cases a bulky firmware installed on shared media must have
a protective partition (with the appropriate flags) to prevent partition
tools from damaging it anyway. In such a case it does not matter if
there is firmware above the 1MB boundary.

> > > EBBR same paragraph also states:
> > > "Automatic partitioning tools (e.g. an OS installer) must not create
> > > partitions within the first 1MiB of storage, or delete, move, or
> > > modify protective partition entries. Manual partitioning tools should
> > > provide warnings when modifying protective partitions or creating
> > > partitions within the first 1MiB."
> > >
> > > is it expected that Linaro upstreams changes in installation tools,
> > > partition tools to conform to this (with updated to be agreed
> > > minimum)?
> >
> > I would expect so, if they aren't already doing that.
> 
> Will need to create initiatives for that.

Pretty much all tools already respect the 1MiB boundary. Sometimes they
use an "expert mode" rather than a explicit warning but I'd view that
as equivalent.

Daniel.
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Re: RFC: EBBR specification update

On Tue, 10 Mar 2020 at 18:19, Daniel Thompson 
wrote:

> On Tue, Mar 10, 2020 at 05:02:27PM +0100, Francois Ozog wrote:
> > Hi,
> >
> > Following implementation (or work towards) of EBBR 1.0 + UEFI Secure
> > boot + UEFI update capsule we learnt a lot.
> >
> > Here are some topics that may need some clarification on the EBBR
> > specs and It looks timely to start working on EBBR evolution.
>
> Thanks for circulating this.
>
> I'm going to respond piecemeal (so I can join the right sub-threads) but
> since so many of your later comments include "Following my view in 0) I
> think this shall be made mandatory" let me kick off with the comment
> below!
>
>
> > 0.1 - EBBR goal
> > May be a reassessment on the "for what" the specification is built.
> >
> > Following all the discussions with prominent industry players, I start
> > to think that limiting the constraints to be EBBR compliant may become
> > counter productive. There will be both EBBR non compliant and EBBR
> > compliant systems. This is inevitable. But EBBR exist for a number of
> > use cases in a number of markets. The value of EBBR is consistent
> > behavior across those.
> >
> > Maximising number of EBBR compliant systems without stating use case
> > parameters ( "why" and "for what") may not be the best goal.
> >
> > Out of things to be more explicit are supported secure boot flows
> > (with/without shim+grub or direct). Some vendors require shim+grub
> > while industry players want the exact opposite: nothing but UEFI. This
> > drivers a number of requirements in terms of UEFI protocols needed
>
> We have resisted levels in EBBR until now but this might be where might
> have a need for them.
>
> Put another way I agree that getting explicit about mandatory features
> for secure boot flows is useful.
>
> However I also think that is remains valuable to define best practice
> for how firmware and OS interact on systems that have not implemented
> secure boot.
>
> It's all about the target use:
1) industrial (manufacturing, automotive, robotics, medical...) components
2) telecom edge
3) 96boards
4) developer desktop
5) server

As I just consider 1 and 2, I have no case without secure boot...
Now the dev platform can come without the secureboot active and
SElinx deactivated
In what context you think this is usefull?


> Daniel.
>


-- 
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.o...@linaro.org | Skype: ffozog
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Re: RFC: EBBR specification update

2020-03-10 Thread Daniel Thompson

On Tue, Mar 10, 2020 at 05:02:27PM +0100, Francois Ozog wrote:
> Hi,
> 
> Following implementation (or work towards) of EBBR 1.0 + UEFI Secure
> boot + UEFI update capsule we learnt a lot.
> 
> Here are some topics that may need some clarification on the EBBR
> specs and It looks timely to start working on EBBR evolution.

Thanks for circulating this.

I'm going to respond piecemeal (so I can join the right sub-threads) but
since so many of your later comments include "Following my view in 0) I
think this shall be made mandatory" let me kick off with the comment
below!

> 0.1 - EBBR goal
> May be a reassessment on the "for what" the specification is built.
> 
> Following all the discussions with prominent industry players, I start
> to think that limiting the constraints to be EBBR compliant may become
> counter productive. There will be both EBBR non compliant and EBBR
> compliant systems. This is inevitable. But EBBR exist for a number of
> use cases in a number of markets. The value of EBBR is consistent
> behavior across those.
> 
> Maximising number of EBBR compliant systems without stating use case
> parameters ( "why" and "for what") may not be the best goal.
> 
> Out of things to be more explicit are supported secure boot flows
> (with/without shim+grub or direct). Some vendors require shim+grub
> while industry players want the exact opposite: nothing but UEFI. This
> drivers a number of requirements in terms of UEFI protocols needed

We have resisted levels in EBBR until now but this might be where might
have a need for them.

Put another way I agree that getting explicit about mandatory features
for secure boot flows is useful.

However I also think that is remains valuable to define best practice
for how firmware and OS interact on systems that have not implemented
secure boot.

Daniel.
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Re: RFC: EBBR specification update