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Subject(XFree86) mmap of /proc/XXX/mem


To initialize secondary graphics cards for the multi-head
feature on XFree86 3.9 it needs to execute the boot up sequence
in the Video BIOS. Also the drivers may make use of Video BIOS
int calls when setting up video modes. On Linux/x86 we use the
vm86-mode to execute the Video BIOS routines. On non-Intel
platforms an emulator is available.

The vm86 mode requires the execute environment (int vectors,
system bios image, vram - in short the DOS real mode environment)
to start at address 0 in virtual address space of the process
calling vm86(). So far the real mode image is initialized during
startup for each card that requests it. When a card wants to
make a BIOS call its real mode image is mapped to address 0
by mmapping /proc/self/mem. However I have reports mmapping
/proc/XXX/mem was removed from later versions of the 2.3 branch.

Is there anybody who knows a workaround for this? If there is
none - and so far I couldn't think of one myself - I would strongly
encourage the kernel developer to re-add this feature.

Regards,
Egbert.

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