#969944 debian-installer: Screen is corrupted with boot parameter VGA=788

Package:
debian-installer
Source:
debian-installer
Description:
Debian Installer documentation
Submitter:
Andrea Palazzi
Date:
2023-04-25 23:15:03 UTC
Severity:
important
Tags:
#969944#5
Date:
2020-09-09 07:15:41 UTC
From:
To:
Dear Maintainer,

I'm installing a Debian Testing using the weekly build 20200907 and the screen
is corrupted and unreadable on my system.
The problem comes either with the graphical install and the expert install;
however if I remove the VGA=788 parameter from the boot line the expert install
screen is ok.
Didn't test the graphical install without this parameter.

I'm using a Radeon Vega 56 gpu.

Andrea
#969944#10
Date:
2023-04-14 00:17:24 UTC
From:
To:
If I change the boot parameter 'VGA=788' to 'VGA='  it works correctly.


AMD Ryzen 5 3500U
Thinkpad E495
debian-bookworm-DI-rc1
#969944#15
Date:
2023-04-14 05:38:38 UTC
From:
To:
I found out that having Secure Boot enabled is necessary to reproduce
this.  With Secure Boot disabled the installer works correctly with the
defaults.
#969944#20
Date:
2023-04-14 05:55:08 UTC
From:
To:
I am sharing a short clip on how debian-bookworm-DI-rc1-amd64-netinst
works when Secure Boot is enabled, and being used with the default boot
parameters (in this case VGA=788).

I hope it helps to identify the issue.
#969944#25
Date:
2023-04-25 18:14:40 UTC
From:
To:
This statement is totally wrong!  I am sorry.

Correction:  In order to reproduce this screen corruption, I have to set
Legacy mode boot in the BIOS,  as you can see in the video (it clearly
states BIOS mode), so:

BIOS set to:

Legacy mode:  Screen corruption.
UEFI:  Works correctly.
UEFI and Secure Boot: Works correctly.

Excuse my mistake.


El 14/4/23 a las 02:38, ng escribió:
#969944#30
Date:
2023-04-25 23:13:22 UTC
From:
To:
Hi ng,

ng <konoha02@yahoo.com> (2023-04-25):

No worries! Thanks for letting us know.


Cheers,