RZG2L and DTB blob from TF-A

[Marek Vasut]

On 9/16/25 2:49 PM, Mathieu Othacehe wrote:
> 
> Hello,

+CC Biju, Chris

> I am working on the RZG2L devkit from Renesas and trying to get the
> mainline U-Boot working there.
> 
> I have noticed that in several locations, U-Boot is unconditionally
> expecting the TF-A to pass a DTB blob:
> 
> In board/renesas/rzg2l/rzg2l.c:
> 
> --8<---------------cut here---------------start------------->8---
> static void apply_atf_overlay(void *fdt_blob)
> {
> 	void *atf_fdt_blob = (void *)(rcar_atf_boot_args[1]);
>          ...
> }
> --8<---------------cut here---------------end--------------->8---
> 
> In arch/arm/mach-renesas/cpu_info-rzg2l.c:
> 
> --8<---------------cut here---------------start------------->8---
> static const struct tfa_info *get_tfa_info(void)
> {
> 	void *atf_fdt_blob = (void *)(rcar_atf_boot_args[1]);
>          ...
> }
> --8<---------------cut here---------------end--------------->8---
> 
> Now, the TF-A that I have compiled (v2.5/rzg2l-1.00-43-g950d6a6b9) from
> https://github.com/renesas-rz/rzg_trusted-firmware-a.git is not passing
> any DTB blob:
> 
> --8<---------------cut here---------------start------------->8---
> INFO:    BL31: Preparing for EL3 exit to normal world
> INFO:    Entry point address = 0x50000000
> INFO:    SPSR = 0x3c5
> VERBOSE: Argument #0 = 0x0
> VERBOSE: Argument #1 = 0x0
> VERBOSE: Argument #2 = 0x0
> VERBOSE: Argument #3 = 0x0
> VERBOSE: Argument #4 = 0x0
> VERBOSE: Argument #5 = 0x0
> VERBOSE: Argument #6 = 0x0
> VERBOSE: Argument #7 = 0x0
> --8<---------------cut here---------------end--------------->8---
> 
> That results in dereferencing a NULL pointer and failing to run U-Boot
> on that platform. On the other hand, disabling the two pieces of code
> mentioned below is enough to have a working U-Boot.
> 
> It does not seem that the upstream TF-A has support for the RZG2L
> CPU. So my question is, what is the expected TF-A branch / repository
> that is meant to be used together with the renesas_rzg2l_smarc_defconfig
> U-Boot configuration?
> 
> Thanks in advance,

Software versions would be good to include, U-Boot version, TFA version.

-- 
Best regards,
Marek Vasut