On 19/04/24 17:04, Sughosh Ganu wrote:
On Fri, 19 Apr 2024 at 16:04, Chintan Vankar <c-van...@ti.com> wrote:
On 18/04/24 17:30, Sughosh Ganu wrote:
On Thu, 18 Apr 2024 at 16:08, Chintan Vankar <c-van...@ti.com> wrote:
On 17/04/24 21:34, Tom Rini wrote:
On Wed, Apr 17, 2024 at 05:48:31PM +0530, Sughosh Ganu wrote:
hi Chintan,
On Wed, 17 Apr 2024 at 13:21, Chintan Vankar <c-van...@ti.com> wrote:
On 16/04/24 22:30, Tom Rini wrote:
On Tue, Apr 16, 2024 at 05:52:58PM +0530, Chintan Vankar wrote:
On 12/04/24 03:37, Tom Rini wrote:
On Wed, Apr 03, 2024 at 06:18:01PM +0530, Chintan Vankar wrote:
On 22/01/24 10:11, Siddharth Vadapalli wrote:
On 20/01/24 22:11, Tom Rini wrote:
On Mon, Jan 15, 2024 at 01:42:51PM +0530, Siddharth Vadapalli wrote:
Hello Tom,
On 12/01/24 18:56, Tom Rini wrote:
...
The list of conditionals in common/spl/spl.c::board_init_r() should be
updated and probably use SPL_NET as the option to check for.
Thank you for reviewing the patch and pointing this out. I wasn't aware of it. I
assume that you are referring to the following change:
if (IS_ENABLED(CONFIG_SPL_OS_BOOT) || CONFIG_IS_ENABLED(HANDOFF)
||
- IS_ENABLED(CONFIG_SPL_ATF))
+ IS_ENABLED(CONFIG_SPL_ATF) || IS_ENABLED(CONFIG_SPL_NET))
dram_init_banksize();
I shall replace the current patch with the above change in the v2 series. Since
this is in the common section, is there a generic reason I could provide in the
commit message rather than the existing commit message which seems to be board
specific? Also, I hope that the above change will not cause regressions for
other non-TI devices. Please let me know.
Yes, that's the area, and just note that networking also requires the
DDR to be initialized.
Thank you for confirming and providing your suggestion for the contents of the
commit message.
Following Tom's Suggestion of adding CONFIG_SPL_NET in common/spl/spl.c
"dram_init_banksize()", the issue of fetching a file at SPL stage seemed
to be fixed. However the commit "ba20b2443c29", which sets gd->ram_top
for the very first time in "spl_enable_cache()" results in
"arch_lmb_reserve()" function reserving memory region from Stack pointer
at "0x81FFB820" to gd->ram_top pointing to "0x100000000". Previously
when gd->ram_top was zero "arch_lmb_reserve()" was noop. Now using TFTP
to fetch U-Boot image at SPL stage results in "tftp_init_load_addr()"
function call that invokes "arch_lmb_reserve()" function, which reserves
entire memory starting from Stack Pointer to gd->ram_top leaving no
space to load U-Boot image via TFTP since TFTP loads files at pre
configured memory address at "0x82000000".
As a workaround for this issue, one solution we can propose is to
disable the checks "lmb_get_free_size()" at SPL and U-Boot stage. For
that we can define a new config option for LMB reserve checks as
"SPL_LMB". This config will be enable by default for the backword
compatibility and disable for our use case at SPL and U-Boot stage.
The problem here is that we need LMB for booting an OS, which is
something we'll want in SPL in non-cortex-R cases too, which means this
platform, so that's a no-go. I think you need to dig harder and see if
you can correct the logic somewhere so that we don't over reserve?
Since this issue is due to function call "lmb_init_and_reserve()"
function invoked from "tftp_init_load_addr()" function. This function
is defined by Simon in commit "a156c47e39ad", which fixes
"CVE-2018-18439" to prevent overwriting reserved memory. Simon, can you
explain why do we need to call "lmb_init_and_reserve()" function here ?
This is indeed a tricky area which is why Sughosh is looking in to
trying to re-work the LMB mechanic and we've had a few long threads
about it as well.
I've honestly forgotten the use case you have here, can you please
remind us?
We are trying to boot AM62x using Ethernet for which we need to load
binary files at SPL and U-Boot stage using TFTP. To store the file we
need a free memory in RAM, specifically we are storing these files at
0x82000000. But we are facing an issue while loading the file since
the memory area having an address 0x82000000 is reserved due to
"lmb_init_and_reserve()" function call. This function is called in
"tftp_init_load_addr()" function which is getting called exactly before
we are trying to get the free memory area by calling
"lmb_get_free_size()".
I have no idea about your platform but I was wondering if there is any
particular importance of the load address of 0x82000000? It looks as
though the current location of the SP when arch_lmb_reserve() gets
called means that the load address is getting reserved for the U-Boot
image. Do you not have the option of loading the image at a lower
address instead?
Sughosh,
I think my explanation was not clear at:
"We are trying to boot AM62x using Ethernet for which we need to load
binary files at SPL and U-Boot stage using TFTP."
- In Ethernet Booting we are fetching U-Boot image at SPL stage via
TFTP at specified address 0x82000000. While loading U-Boot image we are
getting TFTP error, since address from stack pointer till gd->ram_top is
reserved due to "lmb_init_and_reserve()" function call. I want to know
for which purpose this address range is reserved.
On relocation, the U-Boot image is located typically at the top of the
DRAM memory used by U-Boot(ram_top). That region of memory is reserved
to ensure that the memory occupied by the U-Boot image does not get
overwritten by a LMB reservation.
Yes, you are correct about U-Boot relocation but we are facing an issue
at the time of fetching U-Boot proper at SPL stage.
The arch_lmb_reserve_generic() function would reserve the memory
region from the ram_top to the current SP. Btw, you mentioned in an
earlier reply that you are trying to load the U-Boot image at
0x82000000. From the config file it looks like that is the address of
your SPL stack in RAM. So you might be overwriting your SPL stack. I
think you can try a couple of things. One, move the SPL image above
the SPL stack, like it is with U-Boot -- I think the way things stand,
Are you suggesting to relocate SPL image similar to U-Boot relocation. ?
the SPL image is at a lower address than the SP. And then use a lower
address to load the U-Boot image with tftp.
-sughosh
Btw, are you facing this issue in SPL, or U-Boot proper? I built the
images for the am62x_evm_a53 config, and I don't see the
We are getting "TFTP error" at runtime while fetching U-Boot proper at
SPL stage while booting via "Ethernet", and we are using
"am62x_evm_a53_ethboot_defconfig" instead of "am62x_evm_a53_defconfig".
These are the extra configs we are using on top of
"am62x_evm_a53_defconfig":
CONFIG_SPL_DRIVERS_MISC=y
CONFIG_SPL_BOARD_INIT=y
CONFIG_SPL_DMA=y
CONFIG_SPL_ENV_SUPPORT=y
CONFIG_SPL_ETH=y
CONFIG_SPL_NET=y
CONFIG_SPL_NET_VCI_STRING="AM62X U-Boot A53 SPL"
CONFIG_SPL_SYSCON=y
arch_lmb_reserve() function getting included in the SPL image -- both
the .text.arch_lmb_reserve and .text.arch_lmb_reserve_generic are part
of discarded sections. So I am wondering how you are observing this
behaviour in SPL.
-sughosh
Or using a higher address for SPL stack? You might be able to solve this
just by re-examining which addresses (and RAM size limitations) need to
be considered here.
Tom,
We tried this approach of assigning a higher address for SPL stack, but
it is not working as expected.
