On 08/12/25 19:51, Andrew Davis wrote: > On 12/8/25 3:25 AM, Beleswar Prasad Padhi wrote: >> >> On 05/12/25 20:12, Andrew Davis wrote: >>> >>> >>> On 12/5/25 1:32 AM, Beleswar Prasad Padhi wrote: >>>> >>>> On 02/12/25 18:47, Andrew Davis wrote: >>>>> On 12/1/25 11:56 PM, Beleswar Prasad Padhi wrote: >>>>>> >>>>>> On 02/12/25 00:58, Andrew Davis wrote: >>>>>>> On 11/28/25 9:04 AM, Beleswar Padhi wrote: >>>>>>>> The AM571x SoC has 1 GB DDR space. As part of normal re-location >>>>>>>> process >>>>>>>> U-Boot copies itself to the top of DDR bank. However, on HS devices, >>>>>>>> the >>>>>>>> top 37 MB is used by PPA and is firewalled. This results in an >>>>>>>> exception >>>>>>>> and the boot fails. >>>>>>>> >>>>>>>> Introduce a new defconfig for AM571x HS platforms and set >>>>>>>> CONFIG_SYS_MEM_TOP_HIDE to reserve the top 38 MB memory (aligned to 2MB >>>>>>>> as per page size for ARM32) for the same. >>>>>>>> >>>>>>> >>>>>>> This "SYS_MEM_TOP_HIDE" looks new, for other OMAP-class HS devices we >>>>>>> use "CFG_PRAM"[0], seems these two configs do the same thing, could >>>>>>> probably >>>>>>> combine them in some way.. >>>>>>> >>>>>>> As CFG_PRAM is set based on TI_SECURE_EMIF_TOTAL_REGION_SIZE which is >>>>>>> 32MB >>>>>> >>>>>> >>>>>> CFG_PRAM is only set if TI_SECURE_EMIF_REGION_START is not set, but we >>>>>> have it set it to 0xbdb00000 in the am57xx_hs_evm_defconfig. >>>>>> >>>>>> https://github.com/u-boot/u-boot/blob/master/include/configs/ti_omap5_common.h#L75-L81 >>>>>> >>>>>>> for all other AM57x, why is this needed only for AM571? >>>>>> >>>>>> >>>>>> Other AM57x boards have >1 GiB DDR. So, the top of DDR space does not >>>>>> intersect with the firewalled EMIF region (0xbdb00000). Only in case of >>>>>> AM571x, the top of DDR collides with firewalled region, so boot fails >>>>>> while >>>>>> doing reloc. >>>>>> >>>>> >>>>> Is there some way to detect this at runtime? Nothing prevents any of the >>>>> AM57x SoCs being used on boards with 1GB DDR (although they also might use >>>>> a different defconfig). How do we deal with this for K3 devices? Some use >>>>> an OP-TEE address aligned at 512MB and I'm sure one of them have that >>>>> amount >>>>> of DDR. >>>> >>>> >>>> Well, actually not... >>>> It's the AM62 SIP platform. From DT, it would look like OPTEE is at the >>>> top of the >>>> DDR[1], but we do a FDT fixup here in u-boot to replace the OPTEE to the >>>> start >>>> of DDR[2] >>>> >>>> [1]: >>>> https://github.com/torvalds/linux/blob/master/arch/arm64/boot/dts/ti/k3-am62x-sk-common.dtsi#L71 >>>> [2]: >>>> https://github.com/u-boot/u-boot/blob/master/arch/arm/mach-k3/am62x/am625_fdt.c#L84 >>>> >>>> I am not sure if we can do such a thing here for mem used by PPA/firmware >>>> as it could assume it has that memory hardcoded. >>>> >>>>> >>>>>>> We build for all >>>>>>> the AM57x with one defconfig, so this new defconfig will go unused. >>>>>>> Just set >>>>>>> the default CFG_PRAM size to 64MB (same as AM43x), >>>>>> >>>>>> >>>>>> I am guessing all AM43x devices have the same amount of memory unlike >>>>>> AM57x devices? If we set CFG_PRAM to 38MB by default, won't we lose out >>>>>> that memory on other devices which do not face this limitation? >>>>>> >>>>> >>>>> We only really supported "officially" the AM437x-EVM. But our over-focus >>>>> on just our EVMs caused us to make assumptions that would later make >>>>> it difficult to add support for customer boards. Assuming DDR size was >>>>> one such assumption, and should a customer board have the "wrong" DDR >>>>> size things like this would break. >>>>> >>>>> So instead of making another one-off fix to get one of our EVMs working, >>>>> I'm trying to think of a way we can make this work automatically for any >>>>> combination of DDR size and firewalled region. >>>> >>>> TL;DR >>>> I think adding that dynamic support would be tied up only for TI usecase? >>>> >>>> Hmm yes, I get your point. But to be able to do this dynamically, we >>>> would want to see if gd->relocaddr intersects with CFG_PRAM: >>>> >>>> Case 1: >>>> gd->relocaddr > (SECURE_REGION_START + SECURE_REGION_SIZE) >>>> = Best case. U-Boot relocates to an address higher than firewalled addr >>>> >>>> Case 2: >>>> gd->relocaddr <= (SECURE_REGION_START + SECURE_REGION_SIZE) >>>> = Fixup needed. U-Boot relocates to an address which could overlap >>>> with secure region. Update the gd->relocaddr to a lower address range >>>> which won't overlap with secure region: >>>> >>>> reloc_text_size = (RAM_TOP - gd->relocaddr); >>>> gd->relocaddr = SECURE_REGION_START - reloc_text_size; >>>> >>>> >>>> And ofcourse, we can't put this logic in the existing 'reserve_pram'[3] >>>> INITCALL because gd->relocaddr gets modified in the subsequent >>>> initcalls like 'reserve_trace'. We would want to introduce a new >>>> INITCALL which would be invoked after all reserve_* initcalls and >>>> before the reloc_* initcalls; where we can put this logic. >>>> >>>> Let me know if you think this is worth adding, or is an overkill and >>>> we can live happily with CFG_PRAM = 38 MB for all AM57x devices :) >>> >>> Thanks for doing all this evaluation. I don't think this will be >>> the last time we run into this issue, but for now let's just make >>> CFG_PRAM = 64 MB for all AM57x devices and create the perfect solution >>> later. >> >> >> Thanks, I tried setting CFG_PRAM but it still ended up in a firewall >> exception. I guess this is because CFG_PRAM only ensures U-Boot doesn't >> relocate to that protected address[4], however that memory is still open >> for access by anything else if needed. Whereas, SYS_MEM_TOP_HIDE reduces >> the ram size itself[5], which ensures that memory is not visible to >> U-Boot at all (either for reloc, or general usage). > > Seem PRAM ("Protected" RAM) isn't all it claims to be, better route then > is to convert our existing uses of PRAM to SYS_MEM_TOP_HIDE, which seems > more modern and uses KConfig.
Posted patch for the same: https://lore.kernel.org/all/[email protected]/ Thanks, Beleswar > > Andrew > >> >> [4]: https://github.com/u-boot/u-boot/blob/master/common/board_f.c#L391 >> [5]: https://github.com/u-boot/u-boot/blob/master/common/board_f.c#L371 >> >> Thanks, >> Beleswar >> >>> >>> Andrew >>> >>>> >>>> [3]: https://github.com/u-boot/u-boot/blob/master/common/board_f.c#L990 >>>> >>>> Thanks, >>>> Beleswar >>>> >>>>> >>>>> Andrew >>>>> >>>>>> Thanks, >>>>>> Beleswar >>>>>> >>>>>>> should be enough for all >>>>>>> and doesn't hurt to have more than needed reserved to be safe. >>>>>>> >>>>>>> Andrew >>>>>>> >>>>>>> [0] >>>>>>> https://github.com/u-boot/u-boot/blob/master/include/configs/am43xx_evm.h#L153 >>>>>>> >>>>>>>> Signed-off-by: Beleswar Padhi <[email protected]> >>>>>>>> --- >>>>>>>> Fix boot for TI AM571x HS EVM board >>>>>>>> v2: Changelog: >>>>>>>> 1. Drop [PATCH v1 2/2] in v2 series. There is no need to add reserved >>>>>>>> memory node in DT as it is done by U-Boot as part of FDT fixups >>>>>>>> https://github.com/u-boot/u-boot/blob/master/arch/arm/mach-omap2/fdt-common.c#L72-L107 >>>>>>>> 2. Add entry in MAINTAINERS for new config. >>>>>>>> 3. Update commit message to use memory size in MB than raw hex bytes >>>>>>>> >>>>>>>> Link to v1: >>>>>>>> https://lore.kernel.org/all/[email protected]/ >>>>>>>> >>>>>>>> Test logs: >>>>>>>> https://gist.github.com/3V3RYONE/e86b3f4551986b0400d0e0f66d6ecc66 >>>>>>>> >>>>>>>> MAINTAINERS | 1 + >>>>>>>> configs/am571x_hs_evm_defconfig | 3 +++ >>>>>>>> 2 files changed, 4 insertions(+) >>>>>>>> create mode 100644 configs/am571x_hs_evm_defconfig >>>>>>>> >>>>>>>> diff --git a/MAINTAINERS b/MAINTAINERS >>>>>>>> index b43dae882b3..e5d564cd760 100644 >>>>>>>> --- a/MAINTAINERS >>>>>>>> +++ b/MAINTAINERS >>>>>>>> @@ -1780,6 +1780,7 @@ F: configs/am335x_hs_evm_spi_defconfig >>>>>>>> F: configs/am335x_hs_evm_uart_defconfig >>>>>>>> F: configs/am43xx_hs_evm_defconfig >>>>>>>> F: configs/am43xx_hs_evm_qspi_defconfig >>>>>>>> +F: configs/am571x_hs_evm_defconfig >>>>>>>> F: configs/am57xx_hs_evm_defconfig >>>>>>>> F: configs/am57xx_hs_evm_usb_defconfig >>>>>>>> F: configs/dra7xx_hs_evm_defconfig >>>>>>>> diff --git a/configs/am571x_hs_evm_defconfig >>>>>>>> b/configs/am571x_hs_evm_defconfig >>>>>>>> new file mode 100644 >>>>>>>> index 00000000000..7e44ee5221a >>>>>>>> --- /dev/null >>>>>>>> +++ b/configs/am571x_hs_evm_defconfig >>>>>>>> @@ -0,0 +1,3 @@ >>>>>>>> +#include <configs/am57xx_hs_evm_defconfig> >>>>>>>> + >>>>>>>> +CONFIG_SYS_MEM_TOP_HIDE=0x2600000 >>>>>>> >>>>> >>> >
