[syslinux] Problems with gfxboot.c32

[Sebastian Herbszt]

Matt Fleming wrote:
> On Wed, 03 Jul, at 09:53:32PM, Sebastian Herbszt wrote:
>> gfxboot.c32 is supposed to work as expected if you put all required files
>> inside the bootlogo archive.
> 
> From reading com32/gfxboot/gfxboot.c, the code in the bootlog archive
> calls *out* into a realmode section compiled into gfxboot.c32
> (realmode_callback.asm) to do things like open files, read sectors, etc.
> 
> It's these utility functions that no longer work.

Calls to those functions only happen if the gfxboot core (bincode.asm) requests them.
cb_status, cb_fopen and cb_fread are only called from gfxboot core (prim_findfile) if
the requested file is not part of the bootlogo archive.
cb_getcwd is deprecated, cb_chdir and cb_mount were never supported on upstream syslinux.
The only function left is cb_readsector which seems optional in gfxboot core.

There should be no loss of functionality if required files are part of the bootlogo archive.

Sebastian