2012/6/14 Natalia Portillo <clau...@claunia.com>: > Hi Kevin, > > Long time ago I read about OS/2 calling 16-bit protected mode BIOS, but the > documentation didn't specified if this was constrained to the separate > protected mode BIOS included by PS/2 systems or the real mode BIOS included > by the same PS/2 systems and the whole rest of PC computers.
IIRC Borland Pascal 7.0 programs did use 16-bit protected mode ( http://www.monstersoft.com/tutorial1/PM_intro.html ), but I don't have such programs in hand. > > Regards, > Natalia Portillo > > El 14/06/2012, a las 04:13, Kevin O'Connor escribió: > >> Hi, >> >> I am trying to determine if there are legacy applications or operating >> systems that invoke standard BIOS real-mode interrupt handlers while >> in 16bit protected mode. (The legacy real-mode entry points - like >> "int 0x13" - not the declared 16bit protected mode entry points >> defined by the PnP and APM specs.) >> >> I am considering changes to SeaBIOS that would make 16bit protected >> mode callers much less likely to work. (Specifically, enhancing >> SeaBIOS to use memory in the e-segment which is unlikely to be mapped >> in protected mode.) >> >> Most documents I've seen state that calling the real-mode entry points >> in protected mode will not work. Though, I am aware that the PCI BIOS >> spec specifically requires this support for calls to "int 0x1a >> ah=0xb1". >> >> The advantage of making these changes is that it will allow SeaBIOS to >> use notably less stack space and therefore be more compatible with old >> applications that call the BIOS with very little stack space. For >> example, these changes enable DOS 1.0 to boot and run under SeaBIOS. >> >> What would really help is pointers to applications and/or program >> images that use 16bit protected mode calls to real-mode entry points. >> Specifications or documents detailing valid or invalid uses would also >> be helpful. >> >> For those that are willing to run tests, one can compare the standard >> SeaBIOS v1.7.0 image (for KVM/QEMU) at: >> >> http://git.seabios.org/downloads/get/bios.bin-1.7.0.gz >> >> to a test image with the new code at: >> >> http://git.seabios.org/downloads/get/bios.bin-test-20120613.gz >> >> Thanks, >> -Kevin >> >
