S32G resume process check

[Jeff-CF-Huang]

Could you tell me where it  jumps from bl31_warm_entrypoint when resuming? u-boot or linux kernel?

[Daniel-Aguirre]

Hi,

We understand that BL31 should be handled by ATF itself, since the following is told under the BSP User Manual:

"The TF-A is divided into several stages, called Boot Levels (BLs). Arm TF-A specification includes BL1 (Trusted ROM),
BL2 (Trusted Boot Firmware), BL31 (Secure Monitor), BL32 (Trusted OS) and BL33 (non-trusted world, e.g. U-Boot or
UEFI). The BSP 37.0 TF-A implements the BL2 and BL31 stages:"

After this, ATF should load uboot then Linux.

Please, let us know.

[Jeff-CF-Huang]

I have trced the function in s32g_resume.c when system resuming.

Please tell me where it will jump to.

void s32g_resume_entrypoint(void)

{

uintptr_t core_addr;

s32gen1_wkpu_reset();

#if (S32_USE_LINFLEX_IN_BL31 == 1)

console_s32_register();

#endif

if (is_scp_used()) {

core_addr = (uintptr_t)plat_secondary_cold_boot_setup;

scp_set_core_reset_addr(core_addr);

}

bl31_warm_entrypoint();

}

[Daniel-Aguirre]

Hi,

When you are saying "Please tell me where it will jump to.", are you referring to as a function-wise or as an address?

We understand that bl31_warm_entrypoint() is defined under the "bl31_entrypoint.S" file. In here, it is shown it goes to el3_exit function, which is also defined on a different assembler file.

What is the purpose of wanting to know where you are redirected? In the beginning we understood that you were asking as if after wake up it goes to uboot or Linux, for which we still agree that ATF will link to uboot then uboot will link Linux, but we would like to understand more of the purpose for us to understand better the request.

Please, let us know.

[Jeff-CF-Huang]

Please check S32G_Linux_STR_V2-20230519 _eng this document on section 4.2 is saying it will jump to DDR during resuming process.
As my understanding, it won't jump to uboot. It may jump into a function in linux kernel.
My question is sample, which function in uboot or linux kernel it will go to during resume.

If you could provide a full call flow, I will appricate it.

[Daniel-Aguirre]

Hi,

We have received the following update from the internal team:

"

Checked with the S32G_Linux_STR_V2-20230519 _eng document, in the bl31_warm_entrypoint function, it will call the psci_warmboot_entrypoint function. Also the bl31.dump file shows it.

"

Please, let us know.

[Daniel-Aguirre]

Hi,

Thanks for your feedback. We seem to be have a better understanding on what you are looking for. 

Let us confirm within the internal team this information. We apologize for any delay.

Please, let us know.