Found the cause of the red error screen the VSH ends on. Every resource load in
the boot succeeds - fonts, all the plugin RCOs, topmenu_icon.rco - and then:
sceIoOpen(flash0:/vsh/etc/index_02g.dat) -> fd 8
sceIoRead(8, 092a2d40, 496)
sceIoClose(8)
unresolved import sceResmgr/9dc14891, called from 'vsh_module'
sceKernelExitDeleteThread(1)
index_02g.dat is the index of what the XMB displays, and it is encrypted (it
starts "PSPsysGP"). sceResmgr_9DC14891 decrypts it. There was no sceResmgr module
at all, so the call trapped, the index stayed encrypted, and the ScePafJob thread
building the top menu exited - a shell with everything loaded and nothing to show.
This adds the module and the three tags it needs (0x0B2B90F0/91F0/92F0, keys and
code 0x5C) to PrxDecrypter.
It is not the whole fix yet: pspDecryptPRX() tries decryption types 0, 1, 2, 5
and 6, and this needs type 9, which JPCSP passes explicitly. So the call is now
reached and fails cleanly with a logged error instead of trapping, but does not
yet decrypt. Type 9 is a variant of type 2 and is the next job; the notes in
docs/VSHBootInvestigation.md say where it is in JPCSP and how to check a port
(159 bytes out, starting "release:").
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GZq8ZtJmFY7bkX5FVkr3P9