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| author | Michael Brown | 2007-07-09 21:37:39 +0200 |
|---|---|---|
| committer | Michael Brown | 2007-07-09 21:37:39 +0200 |
| commit | b90d321dfb1dfa7228f06ad834e484ee23c9a0c1 (patch) | |
| tree | 26522a7c3cff12690f4fd0a4b5d553b9da45e096 /src/arch/i386/interface/pcbios/int13.c | |
| parent | Proof of concept; works, but has several hard-coded hacks. (diff) | |
| download | ipxe-b90d321dfb1dfa7228f06ad834e484ee23c9a0c1.tar.gz ipxe-b90d321dfb1dfa7228f06ad834e484ee23c9a0c1.tar.xz ipxe-b90d321dfb1dfa7228f06ad834e484ee23c9a0c1.zip | |
Change %dl fixup rules for INT13:
INT 13,08 : read number of drives from 40:75
INT 13,15 : do nothing
all others : restore original value of %dl
Diffstat (limited to 'src/arch/i386/interface/pcbios/int13.c')
| -rw-r--r-- | src/arch/i386/interface/pcbios/int13.c | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/src/arch/i386/interface/pcbios/int13.c b/src/arch/i386/interface/pcbios/int13.c index a4563a05..23fdbf92 100644 --- a/src/arch/i386/interface/pcbios/int13.c +++ b/src/arch/i386/interface/pcbios/int13.c @@ -466,23 +466,28 @@ static void hook_int13 ( void ) { /* Overwrite flags for iret */ "pushfw\n\t" "popw 6(%%bp)\n\t" - /* Restore %dl (except for %ah=0x08 or 0x15) */ - "cmpb $0x08, -1(%%bp)\n\t" - - "jne 7f\n\t" - "movb $2, %%dl\n\t" - "jmp 2f\n\t" - "\n7:\n\t" - - "je 2f\n\t" + /* Fix up %dl: + * + * INT 13,15 : do nothing + * INT 13,08 : load with number of drives + * all others: restore original value + */ "cmpb $0x15, -1(%%bp)\n\t" "je 2f\n\t" "movb -4(%%bp), %%dl\n\t" - "\n2:\n\t" + "cmpb $0x08, -1(%%bp)\n\t" + "jne 2f\n\t" + "pushw %%ds\n\t" + "pushw %1\n\t" + "popw %%ds\n\t" + "movb %c2, %%dl\n\t" + "popw %%ds\n\t" /* Return */ + "\n2:\n\t" "movw %%bp, %%sp\n\t" "popw %%bp\n\t" - "iret\n\t" ) : : "i" ( int13 ) ); + "iret\n\t" ) + : : "i" ( int13 ), "i" ( BDA_SEG ), "i" ( BDA_NUM_DRIVES ) ); hook_bios_interrupt ( 0x13, ( unsigned int ) int13_wrapper, &int13_vector ); |