At 09:52 PM 8/17/2006 +0200, tom ehlert wrote: > > I was a bit worried about the return address getting munged myself, > > but the fact of AX modification is a good reason for why the BIOS bug > > didn't keep biting, and the first patched worked. > >the 'first patch' actually was the original - from the good old times >before Michael entered, and I was sole maintainer of HIMEM. > >I don't know why pushf/cli/popf got even in there, as for any >selfrespecting BIOS, this should have *exactly* no effect (interrupts >are disabled by INT 15, and restored by iret) > >So I assume that pushf/cli/popf got there in the first place because >some buggy real world bios was detected to > > int15handler: > ..... > sti > stc (or whatever flags should be returned) > retf 2 > >and to fix this bug.
Yeah, I don't know. The code shouldn't have changed without a reason. Don't know whether it came before or after the great A20 test-off we had here, perhaps during. I think I remember there being BIOS's which did a RETF 2 instead of an IRET, and maybe they had side-effects similar to the one you describe. Someone who had the time and wanted to do archive-diving back through 2-4 years of software versions and posts might be able to locate the exact change and why, but since it shouldn't matter either way to a non-buggy BIOS, I'm fine with it. ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Freedos-devel mailing list Freedos-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-devel
