This bug has been already fixed in the CVS (v1) as of 2003/09/24. (I remember you said you were using old source)
On Thu, Nov 20, 2003 at 03:08:00PM -0800, Dave Ashley wrote: > Aside from the = vs == bug which probably wasn't too damaging, > the problem was caused because the newer compiler doesn't use > as many registers in its code, specifically the EBX register. > So at the start of the do_vgabios() function it doesn't bother > to push EBX on the stack to preserve it. However code higher > up that calls this function had stored something in EBX, which > the call to the vgabios happily trashes. > > The fix is to push ebx within the real_mode_switch_call_vga function: > /* save the stack */ > "push %ebx\n" > "mov %esp, __stack\n" > > ... > > " mov %ax, %ss \n" > " mov __stack, %esp\n" > "pop %ebx\n" > ); > > It won't hurt to push other registers like %esi for example. In fact > why not push all the registers just to be safe... > > This is a pretty subtle bug, people should understand what was > wrong and how the fix works. > > -Dave > _______________________________________________ > Linuxbios mailing list > [EMAIL PROTECTED] > http://www.clustermatic.org/mailman/listinfo/linuxbios -- Takeshi _______________________________________________ Linuxbios mailing list [EMAIL PROTECTED] http://www.clustermatic.org/mailman/listinfo/linuxbios
