[PATCH v2] configs: am571x_hs_evm_defconfig: Reserve EMIF memory used by PPA

[Beleswar Prasad Padhi]

Hi Tom,

On 15/12/25 22:09, Tom Rini wrote:
> On Fri, Nov 28, 2025 at 08:34:55PM +0530, 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.
>>
>> Signed-off-by: Beleswar Padhi <b-padhi at ti.com>
>> ---
>> 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/20251128064353.1295063-1-b-padhi@ti.com/
>>
>> 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
> Sorry I missed this specific part before. Why isn't this just being
> changed in am57xx_hs_evm_defconfig ? 


The firewalled DDR region and the top of DDR (for U-Boot reloc)
intersects only for AM571x HS device as it has 1 GiB DDR. This
does not happen for other AM57xx HS devices.

> Do we *need* a new config here? 


We can have it reserved in am57xx_hs_evm_defconfig, but that would
hide that RAM from other AM57xx devices which do not face this
limitation. Anyways its just 38MB, so let me know if you prefer to have
it in am57xx_hs_evm_defconfig and I will send out a revision for the
same.

Thanks,
Beleswar

> Or,
> and this gets on to a different topic I've been having with Bryan, is
> there upstream value in this specific config being added? Thanks!
>