static void
handle_legacy_disk(struct bregs *regs, u8 extdrive)
{
if (! CONFIG_DRIVES) {
// XXX - support handle_1301 anyway?
disk_ret(regs, DISK_RET_EPARAM);
return;
}
if (extdrive < EXTSTART_HD) {
struct drive_s *drive_g = getDrive(EXTTYPE_FLOPPY, extdrive);
if (!drive_g)
goto fail;
floppy_13(regs, drive_g);
return;
}
struct drive_s *drive_g;
if (extdrive >= EXTSTART_CD)
drive_g = getDrive(EXTTYPE_CD, extdrive - EXTSTART_CD);
else
drive_g = getDrive(EXTTYPE_HD, extdrive - EXTSTART_HD);
if (!drive_g)
goto fail;
disk_13(regs, drive_g);
return;
fail:
// XXX - support 1301/1308/1315 anyway?
disk_ret(regs, DISK_RET_EPARAM);
}
// INT 13h Fixed Disk Services Entry Point
void VISIBLE16
handle_13(struct bregs *regs)
{
debug_enter(regs, DEBUG_HDL_13);
u8 extdrive = regs->dl;
if (CONFIG_CDROM_EMU) {
if (regs->ah == 0x4b) {
cdemu_134b(regs);
return;
}
u16 ebda_seg = get_ebda_seg();
if (GET_EBDA2(ebda_seg, cdemu.active)) {
u8 emudrive = GET_EBDA2(ebda_seg, cdemu.emulated_extdrive);
if (extdrive == emudrive) {
// Access to an emulated drive.
struct drive_s *cdemu = GET_GLOBAL(cdemu_drive);
if (regs->ah > 0x16) {
// Only old-style commands supported.
disk_13XX(regs, cdemu);
return;
}
disk_13(regs, cdemu);
return;
}
if (extdrive < EXTSTART_CD && ((emudrive ^ extdrive) & 0x80) == 0)
// Adjust id to make room for emulated drive.
extdrive--;
}
}
handle_legacy_disk(regs, extdrive);
}
static void
floppy_13(struct bregs *regs, struct drive_s *drive_gf)
{
// Only limited commands are supported on floppies.
switch (regs->ah) {
case 0x00:
case 0x01:
case 0x02:
case 0x03:
case 0x04:
case 0x05:
case 0x08:
case 0x15:
case 0x16:
disk_13(regs, drive_gf);
break;
default: disk_13XX(regs, drive_gf); break;
}
}
