Adding a new platform: renesas rz

[Mathew McBride]

Hi Michele,

On Mon, Oct 30, 2023, at 8:39 PM, Michele Bisogno wrote:
> Hi,
> 
> I've been a happy OpenWRT user for many years now, always buying
> routers that could allow me to run it easily.
> 
> I've been working (actually only in my free time as a hobby) on
> porting OpenWRT onto this Renesas board:
> https://www.renesas.com/eu/en/products/microcontrollers-microprocessors/rz
> -mpus/rzg2l-evkit-rzg2l-evaluation-board-kit
> which features this Arm Cortex-A55 based device:
> https://www.renesas.com/eu/en/products/microcontrollers-microprocessors/rz
> -mpus/rzg2l-general-purpose-microprocessors-dual-core-arm-cortex-a55-12-gh
> z-cpus-and-single-core-arm-cortex-m33
> 
> I guess this is a new platform, since it does not really fit in any of
> the already supported ones.

Does the Renesas/RZ U-boot have EFI support enabled ('bootefi' command)?
Could you try an armsr/armv8 image and see if it boots?

(You will need to start U-Boot from qspi or sd card and OpenWrt from a USB or different sd card)

If that works, or if we can figure out the necessary changes, a new top level target may not be needed.

I understand Renesas has developed a standard firmware for another CPU in the series (/G2M), but not sure about the /G2L
https://www.renesas.com/us/en/blogs/renesas-rzg2m-awarded-arm-systemready-ir-11-certification

> I got it working and I am polishing the patch before submitting it.
> The support of this device is already mainlined in the Linux kernel,
> so I am using 6.1 as is with the appropriate config.
> Arm Trusted Firmware and u-boot are instead taken from the respective
> Renesas forks, available on github.
At the moment armsr does not have support for building whole machine firmware images with ATF and U-Boot but we could figure out some way to do that if needed.

Best Regards,
Matt