[Bochs-developers] Attempting to resurrect the PSE (4 MB pages) patch

[Johnathan C. <jc...@ae...>]

All,

Scratching an itch, I'm trying to get PSE support working with the
current CVS tree.  There is an ancient patch (March 2000) sitting in the
patches directory (patch.4meg-pages).  I've cleaned it up and gotten it
to compile without error by:

1) Replacing bx_printf calls with BX_INFO invocations
2) Replacing BX_MEM invocations with BX_CPU_THIS_PTR mem-> invocations.

Unfortunately, it doesn't appear to work.  Trying to boot GRUB 0.90
(which works nicely in the unpatched version) makes it to the loading
stage2 portion and then "locks up" with a recurring invalid opcode
exception.  Tracing the instructions shows that the BIOS code is
returning from INT 10 with an IRET to 0x0000:8209 in GRUB, which trails
off into the bushes with 0xFF opcodes.  Not sure what is happening, but
the processor is still in real mode so I don't think any of the page
tranlation code is getting hit here.

I don't know if this ever worked in the first place with the original
patch, and being new the the bochs tree I don't know what the usual
debugging techniques are.  This is using a Debian/sid host and the
current CVS tree.

Here is the URL of the modified patch:

http://www.aeinet.com/people/jcorgan/bochs/patch-bochs-cvs-122801-4meg-pages.diff

Any help or comments would be appreciated.

Johnathan Corgan