Kenneth Culver writes: > > I just looked at the NetBSD code & like linux, they use a macro which > > individually pushes the registers onto the stack rather than using > > pushal (which I assume is the same as what intel calls PUSHAD in their > > x86 instruction set ref. manual). > > > > NetBSD stopped using pushal in 1994 in rev 1.85 of their > > arch/i386/i386/locore.s in a commit helpfully documented > > "Don't use pusha and popa." > > > > Does anybody know why the other OSes push the registers individually, > > rather than using pushal? Could our using pushal be causing Kenneth's > > ebp to get lost, or is this just a red herring? > > > > Thanks, > > > > Drew > > > > > > > according to the intel docs, pushad (or what I'm assuming is pushal in our > case) pushes eax, ecx, edx, ebx then pushes some temporary value (the > original esp I think) then pushes ebp, esi, and edi: > > this is from the documentation for pushad > > IF OperandSize = 32 (* PUSHAD instruction *) > THEN > Temp (ESP); > Push(EAX); > Push(ECX); > Push(EDX); > Push(EBX); > Push(Temp); > Push(EBP); > Push(ESI); > Push(EDI); > > so could this be the problem? > > Ken
I don't think so. The temp its pushing is the stack pointer. If you look at the layout of the trap frame, then you'll see tf_isp comes between tf_ebp & tf_ebx. I assume tf_isp is the stack pointer, so that should be OK.. Drew To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message
