diff options
Diffstat (limited to 'sys/arch/i386/stand/libsa/biosdisk.S')
| -rw-r--r-- | sys/arch/i386/stand/libsa/biosdisk.S | 53 |
1 files changed, 18 insertions, 35 deletions
diff --git a/sys/arch/i386/stand/libsa/biosdisk.S b/sys/arch/i386/stand/libsa/biosdisk.S index f036d0f95c0..f54e23efccc 100644 --- a/sys/arch/i386/stand/libsa/biosdisk.S +++ b/sys/arch/i386/stand/libsa/biosdisk.S @@ -1,4 +1,4 @@ -/* $OpenBSD: biosdisk.S,v 1.2 1997/03/31 03:12:11 weingart Exp $ */ +/* $OpenBSD: biosdisk.S,v 1.3 1997/03/31 23:06:27 mickey Exp $ */ /* * Ported to boot 386BSD by Julian Elischer (julian@tfs.com) Sept 1992 @@ -70,10 +70,7 @@ WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. ENTRY(biosread) pushl %ebp movl %esp, %ebp - pushl %ebx - pushl %esi - pushl %edi - push %es + pushal movb 8(%ebp), %dl # device movw 12(%ebp), %cx @@ -87,44 +84,30 @@ ENTRY(biosread) movb 24(%ebp), %al # number of sectors movl %eax, %esi # save this against mode switch movl 28(%ebp), %ebx # offset - - - # prot_to_real will set %es to BOOTSEG - # Which means %cs == %es. - # XXX - This hoses things severly. Better - # recoup %es to point to the base of the given - # buffer, and let %bx be the index into it, - # that way we can read a max of 64K give or - # take 15 bytes anyways. - - # Save %es in %edi - movl %ebx, %eax - shrl $4, %eax - movl %eax, %edi - andl $0xF, %ebx + movl %ebx, %edi # spilt off for seg:off pair + shrl $4, %edi + andl $0xf, %ebx # atomic read for up to 64k call _C_LABEL(prot_to_real) # enter real mode - # Restore %es movl %di, %es - - # Restore %ax movl %si, %ax - int $0x13 - setc %bl - + movb $0, %cl + jnc 1f + movb %ah, %cl +1: data32 call _C_LABEL(real_to_prot) # back to protected mode - movzbl %bl, %eax # return value in %ax + movzbl %cl, %eax # return value in %ax + movl %eax, 1f - pop %es - popl %edi - popl %esi - popl %ebx + popal + movl 1f, %eax popl %ebp ret +1: .long 0 ENTRY(bioswrite) @@ -142,8 +125,8 @@ ENTRY(biosdinfo) pushl %ebp movl %esp, %ebp pushl %ebx - pushl %esi - pushl %edi + pushl %ecx + pushl %edx movb 8(%ebp), %dl # diskinfo(drive #) @@ -179,8 +162,8 @@ ok: andb $0x3f, %cl # mask of cylinder gunk movb %cl, %al # max sector (and # sectors) - popl %edi - popl %esi + popl %edx + popl %ecx popl %ebx popl %ebp ret |