[PATCH v2 4/4] doc: qemu: arm: Add a section on booting Linux distros

[Simon Glass]

Hi Alper,

On Mon, 14 Aug 2023 at 11:40, Alper Nebi Yasak <alpernebiyasak at gmail.com> wrote:
>
> Add an example qemu-system-aarch64 command that can make U-Boot on QEMU
> boot into the Debian Installer, along with resulting console messages
> from U-Boot, based on the existing documentation section for the x86
> version.
>
> Signed-off-by: Alper Nebi Yasak <alpernebiyasak at gmail.com>
> ---
> I actually want to put the root.img device first so that the VM can boot
> into the installed system when it reboots, but U-Boot can't find the
> bootflow on the second drive. I tried e.g. `bootdev list -p; bootflow
> scan -lab`, but it seems to only ever search the first virtio-blk.
> However, `eficonfig; bootefi bootmgr` makes it boot somehow.

Yes, this is annoying.

The problem is that the scanning is getting so complicated. The
boot_targets var lists things which can either be a uclass, or a
uclass with a device number. The currently implementation sees
"virtio" and moves on to the next thing in boot_targets once it has
processed one virtio device. That is obviously not correct, but...

Would it be possible to just drop the 'boot_targets' var? That is what
is stuffing it up, but we don't actually need it now. The defaults end
up doing the same thing, apart (perhaps) from the strangeness of
virtio which can be both a network and a blk device.

I believe it is possible to do the right thing, but I'll need to
create a better test mechanism to handle all the cases.

>
> Changes in v2:
> - Add new patch for doc section on booting Linux distros
>
>  doc/board/emulation/qemu-arm.rst | 68 ++++++++++++++++++++++++++++++++
>  1 file changed, 68 insertions(+)
>

Regards,
Simon