On Sun, Jul 10, 2022 at 8:49 PM Chenxu Wang via TF-A < tf-a@lists.trustedfirmware.org> wrote:

Hi all, I am using FVP base RevC. Recently I heard that this FVP supports a Mali G76 GPU, and I want to test it.

Can you be more specific? Are you guessing or do you know for sure it is in the public release of FVP models.

To configure it, initially I add a node in linux/arch/arm64/boot/dts/arm/fvp-base-aemv8a-aemv8a.dtsi, but it doesn't work. Finally, I find that I should configure trusted-firmware-a/fdts/fvp-base-gicv3-psci-1t.dts, and I can see a mali GPU node in /proc/device-tree.

OK so there is already a DT with the required node and it works ?

One of my booting command (sorry, the entire booting command is TOO long) is "--data

cluster0.cpu0=arm-reference-platform/output/fvp/fvp-oe/uboot/fvp-base-aemv8a-aemv8a.dtb@0x82000000 ". And I use the following shell command to compile the TF-A: make PLAT=fvp all CROSS_COMPILE=aarch64-none-elf- ENABLE_RME=1 DEBUG=1 ARCH=aarch64 fip BL33=arm-reference-platform/output/fvp/components/fvp/uboot.bin FVP_HW_CONFIG_DTS=fdts/fvp-base-gicv3-psci-1t.dts ARM_DISABLE_TRUSTED_WDOG=1.

I don't understand all these details, but from Linux perspective I would like to know if this is the default release image and what is the behaviour with released TF-A images as that matters a lot.

So, I wonder, why the real DTS is in TF-A, instead of Linux?

Please submit the patch if you prefer to see this in the Linux tree. We need to keep it disabled by default if keeping it enabled causes any boot/runtime regression.

BTW, I wanna ask another question (although it is not proper to ask here, I cannot find FVP's mailing list): Can someone provide a proper dts configurations for FVP's Mali G76 GPU?

I am no expert either. But I would just follow DT bindings upstream and add if anything is missing including the compatibles if any before adding to any upstream DTS.

-- Regards, Sudeep