Re: [PATCH 1/1] efi: avoid video ghosting in EFI app

Hi Heinrich,

On Wed, 5 Aug 2026 at 22:22, Heinrich Schuchardt
<[email protected]> wrote:
>
>
>
> Simon Glass <[email protected]> schrieb am Do., 6. Aug. 2026, 00:00:
>>
>> Hi Heinrich,
>>
>> On 2026-07-31T08:57:24, Heinrich Schuchardt
>> <[email protected]> wrote:
>> > efi: avoid video ghosting in EFI app
>> >
>> > When running the EFI app via QEMU with EDK II using
>> >
>> >   cp /usr/share/OVMF/OVMF_VARS_4M.fd .
>> >   qemu-system-x86_64 -enable-kvm -m 2048 \
>> >     -machine q35,smm=on \
>> >     -drive if=pflash,format=raw,readonly=on,file=/usr/share/OVMF/OVMF_CODE_4M.fd \
>> >     -drive if=pflash,format=raw,file=OVMF_VARS_4M.fd \
>> >     -hda disk
>> >
>> > every character printed to the console by the U-Boot app appears twice. See
>> > https://gist.github.com/xypron/7214e785c7d73104f8541bcac363a192 .
>> >
>> > The reason is that environment variable stdout has serial,vidconsole as
>> > value. This is defined by board/efi/efi-x86_app/efi-x86_app.env including
>> > include/env/x86.env.
>> >
>> > Provide a proper efi-x86_app.env file which does not use vidconsole.
>> >
>> > [...]
>> >
>> > board/efi/efi-x86_app/efi-x86_app.env | 13 ++++++++++++-
>> >  1 file changed, 12 insertions(+), 1 deletion(-)
>>
>> > diff --git a/board/efi/efi-x86_app/efi-x86_app.env b/board/efi/efi-x86_app/efi-x86_app.env
>> > @@ -1,6 +1,17 @@
>> >  /* SPDX-License-Identifier: GPL-2.0+ */
>> > +
>> >  /*
>> >   * Copyright (c) 2015 Google, Inc
>> >   */
>> >
>> > -#include <env/x86.env>
>> > +netdev=eth0
>> > +consoledev=ttyS0
>> > +scriptaddr=0x7000000
>> > +kernel_addr_r=0x1000000
>> > +ramdisk_addr_r=0x4000000
>> > +ramdiskfile=initramfs.gz
>> > +
>> > +/* common console settings */
>> > +stdin=serial
>> > +stdout=serial
>> > +stderr=serial
>>
>> Please can you keep '#include <env/x86.env>' and override just the
>> three console variables afterwards?
>
>
> Hello Simon,
>
> the EFI app should not be x86 specific. You already fixed this in your private repo.

Are you planning to bring in support for ARM, RISC-V, etc? In any
case, if you make a change the commit message should mention it, so
people are not left guessing whether this is intentional or not. BTW
my repo is public :-)

>
> Do you miss any value?
>
>> env2string.awk uses vars[var] =
>> env, so a later assignment wins, and we avoid duplicating netdev,
>> consoledev, scriptaddr, kernel_addr_r, ramdisk_addr_r and ramdiskfile
>> — otherwise any future change to include/env/x86.env will drift away
>> from the EFI app.
>>
>> Also, the previous include pulled in pciconfighost=1 which this
>> version silently drops. If that is intentional it deserves a mention
>> in the commit message; if not, the include-then-override approach
>> fixes it for free.
>
>
> The EFI must not drive any hardware directly. There is no value in pciconfighost.

Again, please just put this comment in the commit message.

>
> Best regards
>
> Heinrich
>
>>
>> BTW an alternative is to leave x86.env alone and make the vidconsole
>> entries conditional on something like !defined(CONFIG_EFI_APP), so
>> efi-x86_payload.env and the other x86 boards keep sharing one source
>> of truth. What do you think?

Regards,
Simon