Re: The state of Arm64 on Raspberry Pi (and its Documentation
On Tue, Mar 31, 2020 at 7:08 PM Pete Batard <pete@akeo.ie> wrote:
>
> Hi Gene,
>
> On 2020.03.31 17:41, Gene Heskett wrote:
> >> The only thing that's missing, really, is for Debian folks to
> >> integrate the retrofitted Genet network driver, which we submitted 2
> >> months ago, in the vanilla aarch64 installation images...
> >>
> > Tweaks my curiosity. That driver doesn't exist in the raspi armhf build
> > from raspbian, yet the networking is flawless. I run a host file based
> > net config, and it Just works.
>
> That's because it uses Device Tree, and the DT based version of the
> Genet driver has been in the kernel for a while, so it should be mostly
> okay.
>
> But we have to use ACPI in UEFI for various reasons. The Pi 4 has a few
> quirks, especially when it comes to DMA and USB, that paradoxically make
> an ACPI implementation easier to sort out compared to DT. This doesn't
> mean we won't support DT, just that ACPI is more suitable for now. So we
> need ACPI bindings in Genet, whereas the existing Genet driver is
> intended as a DT mode driver.
There is no need to use ACPI when using the UEFI boot path, that can
just as well work with a normal DT. There is also no need to use UEFI for
booting a 64 bit kernel, most bootloaders only use the native ARM64
boot protocol, although u-boot can do either one these days.
Do you have a pointer to what the issues with USB and DMA are?
Arnd
Reply to: