Bug#278147: sparc32 cannot mount cdrom in d-i

[Jurij Smakov <jurij@wooyd.org>]

Hello,

I believe that this problem happens due to the fact that the isofs.o 
module is currently not included into d-i on sparc32. The culprit is most 
likely the linux-kernel-di-sparc package (current version 0.61), which 
does not include isofs into the list of modules on sparc32, but does it 
for sparc64:

bash$ grep isofs linux-kernel-di-sparc-0.61/modules/sparc/*
bash$

bash$ grep isofs linux-kernel-di-sparc-0.61/modules/sparc64/*
linux-kernel-di-sparc-0.61/modules/sparc64/ide-modules:fs/isofs/isofs.o
bash$

This does not explain why one gets a 'NULL pointer dereference' though. 
I was able to trace it (by matching the PC and System.map) to some 
functions, called from romfs_read_super. My (yet unconfirmed) suspicion is 
that when the fs type is not specified while mounting, kernel tries all 
filesystems in turn, looking for the correct one. So, when isofs 
filesystem driver is not available, it tries to mount the iso as romfs 
(among other things), exposing some unrelated bug in romfs code :-).

Hope it helps,

Jurij Smakov                                        jurij@wooyd.org
Key: http://www.wooyd.org/pgpkey/                   KeyID: C99E03CC