Hi,

This issue looks related to the following ticket: https://developer.trustedfirmware.org/T661

It was corrected for argument passing from BL2 to BL32, in aarch32 mode, see patch: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3518

Could you try the same change in bl2/aarch32/bl2_entrypoint.S? And if it is OK for you, propose the patch?

You can check the following page for how to contribute:

https://trustedfirmware-a.readthedocs.io/en/latest/process/contributing.html

Best regards, Yann

On 5/15/22 10:57, 邬金平 via TF-A wrote:

Hi

Arguments between the BL1 and BL2 is overlap by zeromem when BL2 start.

1. BL2 save r3 to r12

arm-trusted-firmware/bl2/aarch32/bl2_entrypoint.S /*---------------------------------------------      * Save arguments x0 - x3 from BL1 for future      * use.      * ---------------------------------------------      */ mov r9, r0 mov r10, r1 mov r11, r2 mov r12, r3

2. BL2 call zeromem to clear bss

arm-trusted-firmware/bl2/aarch32/bl2_entrypoint.S ldr r0, =__BSS_START__ ldr r1, =__BSS_END__ sub r1, r1, r0 bl zeromem

arm-trusted-firmware/lib/aarch32/misc_helpers.S tmp .req r12 /* Temporary scratch register */ r12 used as scratch register

3. r3 restore from r12

arm-trusted-firmware/bl2/aarch32/bl2_entrypoint.S mov r0, r9 mov r1, r10 mov r2, r11 mov r3, r12

I can try to save it in other registers, but can not guarantee that the register will not be damaged. Is there any better way to deal with this problem? Thanks.