Re: [9front] 9front and raspberry pi 4 8gb model

[Roman Shaposhnik <roman@shaposhnik.org>]

On Sat, Jun 13, 2020 at 6:56 PM <cinap_lenrek@felloff.net> wrote:
>
> > Btw, the following thread may be helpful:
> > https://lists.denx.de/pipermail/u-boot/2020-April/405216.html
>
> this is probably not the issue. the xhci works fine with the 1gb and 2gb
> variants. and the issue they had was that they missed flushing the
> dcache for the scratchpad memory they hand to the xhci controller.
>
> we do flush the dcache for these regions here:
>
>                 dmaflush(1, ctlr->sbp, ctlr->nscratch*ctlr->pagesize);
>                 dmaflush(1, ctlr->sba, ctlr->nscratch*8);

Upon closer examination you may be right.

That said -- in general I feel that retracing u-boot steps in
supporting USB boot on RPi4 8Gb may be easier than retracing steps of
the Linux kernel.

Thanks,
Roman.