On Sat, Dec 17, 2011 at 3:50 PM, Julian Pidancet julian.pidancet@gmail.com wrote:
On Sat, Dec 17, 2011 at 3:38 PM, Kevin O'Connor kevin@koconnor.net wrote:
On Fri, Dec 16, 2011 at 02:15:07PM +0000, Julian Pidancet wrote:
The real-mode emulator that Windows 7 uses to execute the vga bios rom becomes very confused when the code tries to dereference the stack pointer instead of using the frame pointer, leading to corruption of parameters passed on the stack from one function to another.
Signed-off-by: Julian Pidancet julian.pidancet@gmail.com
Wow - I can only imagine how hard it was to find that.
I'm okay with turning off omit-frame-pointer for the vga bios. However, I'd prefer not to turn it off for the main seabios build. Does the emulator also try to emulate parts of the BIOS, which would make that a problem?
Besides the functions which are common to both the BIOS and the VGA ROM ( src/output.c and src/util.c), it doesn't seem to make any particular problem with the rest of the BIOS.
The VGA ROM and the BIOS currently share the same CFLAGS. Due to the way the Makefile is written at the moment, I can hardly see how to modify it to compile both binaries with different CFLAGS without making a mess in the Makefile. Do you have any recommendations ?
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Julian Pidancet