Re: [PATCH v1 0/4] k3: migrate SPL_TEXT_BASE to new address

[Anshul Dalal <anshuld@ti.com>]

On Wed Apr 16, 2025 at 4:54 PM IST, Nishanth Menon wrote:
> On 13:00-20250416, Anshul Dalal wrote:
>> The change to ATF's PRELOADED_BL33_BASE[1] requires respective changes to
>> SPL_TEXT_BASE on u-boot side. This is necessary to allow the ATF to jump
>> directly to linux kernel (like in falcon mode) which requires a 2MiB aligned
>> load address[2]. The current address ATF jumps to is 0x80080000 which is not
>> 2MiB aligned.
>> 
>> Therefore in parallel to the ATF change, this patch set makes the corresponding
>> changes to u-boot. To maintain backwards compatibility with older ATF builds
>> (that still use older address of 0x80080000), the patch set also adds a
>> jump-stub which modifies the execution as follows:
>> 
>> Old ATF -> 0x80080000 -> 0x822000000 (Main domain SPL or kernel image)
>>            jump stub    SPL_TEXT_BASE
>> 
>> With the following instructions loaded by the jump-stub:
>> ADDR       | Instruction
>> 0x80080000 |   mov x15, CONFIG_SPL_TEXT_BASE (0x822000000)
>> 0x80080004 |   br x15
>> 
>> Depends on:
>>  * [PATCH v3] configs: set SPL_TEXT_BASE by default for k3 platforms
>>    https://lore.kernel.org/u-boot/20250415095028.446254-1-anshuld@ti.com/
>> 
>> [1]:
>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/37447
>> [2]:
>> "The Image must be placed text_offset bytes from a 2MB aligned base
>> address anywhere in usable system RAM and called there."
>> - Documentation/arch/arm64/booting.rst (linux kernel)
>> 
>> Anshul Dalal (4):
>>   spl: Kconfig: k3: set SPL_TEXT_BASE to 0x82200000
>>   mach-k3: add a jump stub to support older ATF builds
>>   binman: k3: add jump-stub to tispl.bin
>>   binman: k3: add jump-stub as loadable
>
>
> 	How about u-boot documentation?

I will update that in the next revision along with any feedback I
receive on this patch.

Regards

>> 
>>  arch/arm/dts/k3-am625-beagleplay-u-boot.dtsi  |  2 +-
>>  arch/arm/dts/k3-am625-phycore-som-binman.dtsi |  4 +--
>>  arch/arm/dts/k3-am625-sk-binman.dtsi          |  4 +--
>>  .../dts/k3-am625-verdin-wifi-dev-binman.dtsi  |  4 +--
>>  arch/arm/dts/k3-am62a-phycore-som-binman.dtsi |  4 +--
>>  arch/arm/dts/k3-am62a-sk-binman.dtsi          |  4 +--
>>  arch/arm/dts/k3-am62p-sk-binman.dtsi          |  2 +-
>>  arch/arm/dts/k3-am642-phycore-som-binman.dtsi |  8 ++---
>>  arch/arm/dts/k3-am64x-binman.dtsi             |  8 ++---
>>  arch/arm/dts/k3-am65-iot2050-boot-image.dtsi  |  2 +-
>>  arch/arm/dts/k3-am65x-binman.dtsi             |  4 +--
>>  arch/arm/dts/k3-am67a-beagley-ai-u-boot.dtsi  |  2 +-
>>  arch/arm/dts/k3-binman.dtsi                   | 31 +++++++++++++++++++
>>  arch/arm/dts/k3-j7200-binman.dtsi             |  4 +--
>>  .../dts/k3-j721e-beagleboneai64-u-boot.dtsi   |  2 +-
>>  arch/arm/dts/k3-j721e-binman.dtsi             |  4 +--
>>  arch/arm/dts/k3-j721s2-binman.dtsi            |  4 +--
>>  arch/arm/dts/k3-j722s-binman.dtsi             |  2 +-
>>  arch/arm/dts/k3-j784s4-binman.dtsi            |  4 +--
>>  arch/arm/mach-k3/Makefile                     |  7 +++++
>>  arch/arm/mach-k3/jump_stub.S                  | 16 ++++++++++
>>  common/spl/Kconfig                            |  2 +-
>>  22 files changed, 89 insertions(+), 35 deletions(-)
>>  create mode 100644 arch/arm/mach-k3/jump_stub.S
>> 
>> -- 
>> 2.49.0
>>