On 23.10.23 13:30, Daniel Thompson wrote:
On Fri, Oct 20, 2023 at 09:10:45AM -0500, Jon Humphreys wrote:
Heinrich Schuchardt <heinrich.schucha...@canonical.com> writes:
I personally would prefer firmware using the firmware folder in the ESP
over using a firmware partition because the partitioning scheme would
not be firmware specific.
I argue the opposite (again I'm new to this so open to learning!). My
view: we want all the firmware bits to be owned and specific to the
board and the board/firmware presents a standard API to the OS. The OS
should own the ESP so it can modify it, set boot order, etc. For these
reasons, you want the firmware location to be different than the ESP.
For updateability, of course the firmware's location can't be unknown to
the OS.
But my point in this is about where it comes from. The firmware must
come from the board provider, and the ESP from the OS provider, so they
must be in different locations.
As I type this, I realize I have 2 assumptions that may not be correct:
1) the ESP should come from the OS provider. True? At least this seems
to be the common practice.
Pretty much.
On a system with multiple OSes they are something of a shared space between
multiple OS providers. That means the OS providers try not to stand on
each others toes! That means, in general, OS installers are designed
to leave the ESP mostly as they found it (apart from installing their
bootloaders).
However an installer typically won't do much to stop the user choosing
to reformat or resizing the ESP since, on systems without firmware in
the ESP, this is an entirely legitimate thing to do when entirely
replacing one OS with another.
2) the EBBR wants the OS to have direct access to the firmware for
updates. True? Or is the thinking that the OS should not have direct
access but should only update via other mechanisms like capsule update?
Not as far as I remember. Capsules are the preferred update mechanism.
Daniel.
I prefer if the firmware is provided with the board and is not installed
on any medium that the OS manages, e.g. SPI flash or an eMMC boot
partitions.
Unfortunately many boards don't follow this approach. Their boot ROM
loads the firmware from SD card or another mountable device.
The whole discussion is about these cases only.
Often it is the Linux distribution that supplies the firmware. See the
u-boot source package in Debian and derivatives.
If the firmware lives on a block device also used by the operating
system, we must find a solution minimizing conflicts.
Files in a firmware directory on the ESP have little impact on operating
systems. I would prefer this to having device specific partitioning
requirements.
Usage of capsule updates does not imply the storage location.
Best regards
Heinrich
_______________________________________________
boot-architecture mailing list -- boot-architecture@lists.linaro.org
To unsubscribe send an email to boot-architecture-le...@lists.linaro.org
