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 :) [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 >>> >
