PSP: Nightly build does not start on physical PSP-1000

[lolbot-iichan]

TESTCASE:

1. Download nightly build (e.g. ​https://buildbot.scummvm.org/snapshots/master/psp-master-d67b16a5.tar.xz)
2. Unpack it to ms0:/PSP/GAME/ of actual physical Memory Stick™
3. Remove ms0:/scummvm.ini for a clear start
4. Insert Memory Stick™ to actual physical PSP-1000
5. Select ScummVM application and try to start it

EXPECTED RESULT:
ScummVM starts, game list is displayed

ACTUAL RESULT:
Screen is black, IO indicator blinks repeatedly for several seconds, then console silently powers off

LOGS:
ms0:/PSP/GAME/psp-master-d67b16a5/SCUMMTRACE.TXT file is created with just a single line:

Error in static void PSPPixelFormat::convertFromScummvmPixelFormat(const Graphics::PixelFormat*, PSPPixelFormat::Type&, PSPPixelFormat::Type&, bool&): Unknown bpp[4] in pixeltype. Reverting to 8bpp

I don't know how to enable debug logs on PSP, adding debuglevel=11 to scummvm.ini does not work for me.

NOTE:
Stable build ​https://downloads.scummvm.org/frs/scummvm/2.2.0/scummvm-2.2.0-psp.zip works fine.

[lolbot-iichan]

This may be related to #12498

[rsn8887]

I can reproduce this on my real PSP-2000.

First commit that introduces this crash is this one: ​https://github.com/scummvm/scummvm/commit/0fc5c4c3916992691b3c8777e8ffaaf45af99ba5

0fc5c4c3916992691b3c8777e8ffaaf45af99ba5 is the first bad commit
commit 0fc5c4c3916992691b3c8777e8ffaaf45af99ba5
Author: Eugene Sandulenko <sev@…>
Date: Sat Apr 10 02:41:23 2021 +0200

GUI: Keep SVGs in 32-bit format until very rendering

gui/ThemeEngine.cpp | 2 +-
gui/widget.cpp | 14 --------------
2 files changed, 1 insertion(+), 15 deletions(-)

The commit before works great, with correct mousepointer and all.

[rsn8887]

Fixed with ​https://github.com/scummvm/scummvm/commit/8ab7d43079f505d1a61522165d465545b4aa9d74

Thanks @SupSuper for the fix!