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| author | Michael Brown | 2007-07-05 14:30:49 +0200 |
|---|---|---|
| committer | Michael Brown | 2007-07-05 14:30:49 +0200 |
| commit | a0f078d7f5e91a557df14dccf932dad7f7eb5055 (patch) | |
| tree | eb178abe483a1520da38e06f6706e053b5185537 | |
| parent | hdprefix that works for LBA only (diff) | |
| download | ipxe-a0f078d7f5e91a557df14dccf932dad7f7eb5055.tar.gz ipxe-a0f078d7f5e91a557df14dccf932dad7f7eb5055.tar.xz ipxe-a0f078d7f5e91a557df14dccf932dad7f7eb5055.zip | |
Working with multi-sector reads
| -rw-r--r-- | src/arch/i386/prefix/hdprefix.S | 48 |
1 files changed, 40 insertions, 8 deletions
diff --git a/src/arch/i386/prefix/hdprefix.S b/src/arch/i386/prefix/hdprefix.S index 68392d2c3..ceab20614 100644 --- a/src/arch/i386/prefix/hdprefix.S +++ b/src/arch/i386/prefix/hdprefix.S @@ -10,29 +10,61 @@ #include "bootpart.S" load_image: - movw $_rom_size, %bp -1: /* Truncate read length to end of track */ - movzwl %bp, %eax - movw $1, %ax - /* Read sectors */ + /* Get disk geometry */ + pushal + pushw %es + movb $0x08, %ah + int $0x13 + jc load_failed + movb %cl, max_sector + movb %dh, max_head + popw %es + popal + +1: /* Read to end of current track */ + movb %cl, %al + negb %al + addb max_sector, %al + incb %al + andb $0x3f, %al + movzbl %al, %eax call *read_sectors jc load_failed + /* Update %es */ movw %es, %bx shll $5, %eax addw %ax, %bx movw %bx, %es shrl $5, %eax + /* Update LBA address */ addl %eax, %edi adcl $0, %esi + /* Update CHS address */ - // hmmmm + andb $0xc0, %cl + orb $0x01, %cl + incb %dh + cmpb max_head, %dh + jbe 2f + xorb %dh, %dh + incb %ch + jnc 2f + addb $0xc0, %cl +2: /* Loop until whole image is read */ - subw %ax, %bp - jne 1b + subl %eax, load_length + ja 1b ljmp $BOOT_SEG, $start_image +load_length: + .long _rom_size +max_sector: + .byte 0 +max_head: + .byte 0 + load_failed: movw $10f, %si jmp boot_error |