Re: [1/2 very MD part] Support Raspberry Pi [0-3] in big-endian mode

[Rin Okuyama <rokuyama.rk%gmail.com@localhost>]

Hi,

Thank you very much for your kind review!

On 2020/11/22 23:46, Nick Hudson wrote:
> On 15/11/2020 12:44, Rin Okuyama wrote:
> > Hi,
> >
> > I've managed Raspberry Pi [0-3] to work in big-endian mode:
> >
> > - Zero and 1 in earmv6{,hf}eb
> > - 2 and 3 in earmv7{,hf}eb
> > - 3 in aarch64eb
> >
> > Now, everything except vchiq(4) work without problems.
> >
> > (1) Data written/read to/from mailbox and dmac should be encoded in
> >      little-endian.
> >
> > http://www.netbsd.org/~rin/rpi_eb_md_20201115.patch
>
> LGTM apart from I don't understand why
> bcm2835_aux_platform_early_putchar appears

This function is used for EARLYCONS on Pi Zero W, for which output
must go to AUX UART instead of PL011. This should have been addressed
separately. Sorry for confusing you. I committed this part already.

> Also, I'd prefer the whitespace / stylistic changes committed separately
> where possible.

Sure. I committed stylistic changes separately.

MD parts of patch has been updated accordingly:
http://www.netbsd.org/~rin/rpi_eb_md_20201123.patch

> > (2) DMA buffer for vchiq(4) should also be encoded in little-endian.
> >      However, this require heavy modification to 3rd party sources.
> >      At the moment, I disabled vchiq(4) for armeb/aarch64eb.
> >
> > http://www.netbsd.org/~rin/rpi_eb_vchiq_20201115.patch
>
> vchiq should probably die in favour of VC4 DRM etc. Not sure what
> happens wrt audio though.

Good to hear this comment before I try to modify vchiq codes :).
I will just disable this for big-endian mode.

Thanks,
rin