forked from KolibriOS/kolibrios
Style corrected for new rules, no semantic changes
git-svn-id: svn://kolibrios.org@2288 a494cfbc-eb01-0410-851d-a64ba20cac60
This commit is contained in:
CleverMouse
@@ -1,358 +1,358 @@
|
||||
; Copyright (c) 2008-2009, diamond
|
||||
; All rights reserved.
|
||||
;
|
||||
; Redistribution and use in source and binary forms, with or without
|
||||
; modification, are permitted provided that the following conditions are met:
|
||||
; * Redistributions of source code must retain the above copyright
|
||||
; notice, this list of conditions and the following disclaimer.
|
||||
; * Redistributions in binary form must reproduce the above copyright
|
||||
; notice, this list of conditions and the following disclaimer in the
|
||||
; documentation and/or other materials provided with the distribution.
|
||||
; * Neither the name of the <organization> nor the
|
||||
; names of its contributors may be used to endorse or promote products
|
||||
; derived from this software without specific prior written permission.
|
||||
;
|
||||
; THIS SOFTWARE IS PROVIDED BY Alexey Teplov aka <Lrz> ''AS IS'' AND ANY
|
||||
; EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
||||
; WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
||||
; DISCLAIMED. IN NO EVENT SHALL <copyright holder> BE LIABLE FOR ANY
|
||||
; DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
||||
; (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
||||
; ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
||||
; (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
||||
; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
;*****************************************************************************
|
||||
|
||||
use_lba = 0
|
||||
org 0x7C00
|
||||
jmp start
|
||||
nop
|
||||
; FAT parameters, BPB
|
||||
; they must be changed at install, replaced with real values
|
||||
rb 8 ; BS_OEMName, ignored
|
||||
dw 200h ; BPB_BytsPerSec
|
||||
BPB_SecsPerClus db ?
|
||||
BPB_RsvdSecCnt dw ?
|
||||
BPB_NumFATs db ?
|
||||
BPB_RootEntCnt dw ?
|
||||
dw ? ; BPB_TotSec16
|
||||
db ? ; BPB_Media
|
||||
dw ? ; BPB_FATSz16 = 0 for FAT32
|
||||
BPB_SecPerTrk dw ?
|
||||
BPB_NumHeads dw ?
|
||||
BPB_HiddSec dd ?
|
||||
dd ? ; BPB_TotSec32
|
||||
BPB_FATSz32 dd ?
|
||||
BPB_ExtFlags dw ?
|
||||
dw ? ; BPB_FSVer
|
||||
BPB_RootClus dd ?
|
||||
dw ? ; BPB_FSInfo
|
||||
BPB_BkBootSec dw ?
|
||||
rb 12 ; BPB_Reserved
|
||||
BS_DrvNum db ?
|
||||
db ? ; BS_Reserved1
|
||||
db ? ; BS_BootSig
|
||||
dd ? ; BS_VolID
|
||||
rb 11 ; BS_VolLab
|
||||
rb 8 ;
|
||||
|
||||
curseg dw 0x8000
|
||||
|
||||
start:
|
||||
xor ax, ax
|
||||
mov ss, ax
|
||||
mov sp, 0x7C00
|
||||
mov ds, ax
|
||||
mov bp, sp
|
||||
cld
|
||||
sti
|
||||
push dx ; byte [bp-2] = boot drive
|
||||
if use_lba
|
||||
mov ah, 41h
|
||||
mov bx, 55AAh
|
||||
int 13h
|
||||
mov si, aNoLBA
|
||||
jc err_
|
||||
cmp bx, 0AA55h
|
||||
jnz err_
|
||||
test cl, 1
|
||||
jz err_
|
||||
else
|
||||
mov ah, 8
|
||||
int 13h
|
||||
jc @f
|
||||
movzx ax, dh
|
||||
inc ax
|
||||
mov [bp+BPB_NumHeads-0x7C00], ax
|
||||
and cx, 3Fh
|
||||
mov [bp+BPB_SecPerTrk-0x7C00], cx
|
||||
@@:
|
||||
end if
|
||||
; get FAT parameters
|
||||
xor bx, bx
|
||||
movzx eax, [bp+BPB_NumFATs-0x7C00]
|
||||
mul [bp+BPB_FATSz32-0x7C00]
|
||||
movzx ecx, [bp+BPB_RsvdSecCnt-0x7C00]
|
||||
push ecx ; FAT start = dword [bp-6]
|
||||
add eax, ecx
|
||||
push eax ; data start = dword [bp-10]
|
||||
;push dword -1 ; dword [bp-14] = current sector for FAT cache
|
||||
db 66h
|
||||
push -1 ; dword [bp-14] = current sector for FAT cache
|
||||
mov eax, [bp+BPB_RootClus-0x7C00]
|
||||
mov si, main_loader
|
||||
call lookup_in_dir
|
||||
jnc kordldr_ok
|
||||
noloader:
|
||||
mov si, aLoaderNotFound
|
||||
err_:
|
||||
call out_string
|
||||
mov si, aPressAnyKey
|
||||
call out_string
|
||||
xor ax, ax
|
||||
int 16h
|
||||
int 18h
|
||||
jmp $
|
||||
kordldr_ok:
|
||||
mov eax, [es:di+20-2] ; hiword(eax) = hiword(cluster)
|
||||
mov ax, [es:di+26] ; loword(eax) = loword(cluster)
|
||||
mov es, bx ; es = 0
|
||||
mov bx, 0x7E00
|
||||
push bx ; save return address: bx = 7E00
|
||||
; fall through - 'ret' in read_cluster will return to 7E00
|
||||
|
||||
read_cluster:
|
||||
; ss:bp = 0:7C00
|
||||
; es:bx = pointer to data
|
||||
; eax = cluster
|
||||
sub eax, 2
|
||||
movzx ecx, [bp+BPB_SecsPerClus-0x7C00]
|
||||
mul ecx
|
||||
|
||||
read_sectors2:
|
||||
; same as read_sectors32, but eax is relative to start of data
|
||||
add eax, [bp-10]
|
||||
read_sectors32:
|
||||
; ss:bp = 0:7C00
|
||||
; es:bx = pointer to data
|
||||
; eax = first sector
|
||||
; cx = number of sectors
|
||||
; some high words of 32-bit registers are destroyed!
|
||||
pusha
|
||||
add eax, [bp+BPB_HiddSec-0x7C00]
|
||||
if use_lba
|
||||
push ds
|
||||
do_read_sectors:
|
||||
push ax
|
||||
push cx
|
||||
cmp cx, 0x7F
|
||||
jbe @f
|
||||
mov cx, 0x7F
|
||||
@@:
|
||||
; create disk address packet on the stack
|
||||
; dq starting LBA
|
||||
push 0
|
||||
push 0
|
||||
push eax
|
||||
; dd buffer
|
||||
push es
|
||||
push bx
|
||||
; dw number of blocks to transfer (no more than 0x7F)
|
||||
push cx
|
||||
; dw packet size in bytes
|
||||
push 10h
|
||||
; issue BIOS call
|
||||
push ss
|
||||
pop ds
|
||||
mov si, sp
|
||||
mov dl, [bp-2]
|
||||
mov ah, 42h
|
||||
int 13h
|
||||
mov si, aReadError
|
||||
jc err_
|
||||
; restore stack
|
||||
add sp, 10h
|
||||
; increase current sector & buffer; decrease number of sectors
|
||||
movzx esi, cx
|
||||
mov ax, es
|
||||
shl cx, 5
|
||||
add ax, cx
|
||||
mov es, ax
|
||||
pop cx
|
||||
pop ax
|
||||
add eax, esi
|
||||
sub cx, si
|
||||
jnz do_read_sectors
|
||||
pop ds
|
||||
popa
|
||||
ret
|
||||
else
|
||||
do_read_sectors:
|
||||
pusha
|
||||
pop edi ; loword(edi) = di, hiword(edi) = si
|
||||
push bx
|
||||
|
||||
; eax / (SectorsPerTrack) -> eax, remainder bx
|
||||
movzx esi, [bp+BPB_SecPerTrk-0x7C00]
|
||||
xor edx, edx
|
||||
div esi
|
||||
mov bx, dx ; bx=sector-1
|
||||
|
||||
; eax -> dx:ax
|
||||
push eax
|
||||
pop ax
|
||||
pop dx
|
||||
; (dword in dx:ax) / (NumHeads) -> (word in ax), remainder dx
|
||||
div [bp+BPB_NumHeads-0x7C00]
|
||||
|
||||
; number of sectors: read no more than to end of track
|
||||
sub si, bx
|
||||
cmp cx, si
|
||||
jbe @f
|
||||
mov cx, si
|
||||
@@:
|
||||
|
||||
inc bx
|
||||
; now ax=track, dl=head, dh=0, cl=number of sectors, ch=0, bl=sector; convert to int13 format
|
||||
movzx edi, cx
|
||||
mov dh, dl
|
||||
mov dl, [bp-2]
|
||||
shl ah, 6
|
||||
mov ch, al
|
||||
mov al, cl
|
||||
mov cl, bl
|
||||
or cl, ah
|
||||
pop bx
|
||||
mov si, 3
|
||||
mov ah, 2
|
||||
@@:
|
||||
push ax
|
||||
int 13h
|
||||
jnc @f
|
||||
xor ax, ax
|
||||
int 13h ; reset drive
|
||||
pop ax
|
||||
dec si
|
||||
jnz @b
|
||||
mov si, aReadError
|
||||
jmp err_
|
||||
@@:
|
||||
pop ax
|
||||
mov ax, es
|
||||
mov cx, di
|
||||
shl cx, 5
|
||||
add ax, cx
|
||||
mov es, ax
|
||||
push edi
|
||||
popa
|
||||
add eax, edi
|
||||
sub cx, di
|
||||
jnz do_read_sectors
|
||||
popa
|
||||
ret
|
||||
end if
|
||||
|
||||
lookup_in_dir:
|
||||
; in: ds:si -> 11-bytes FAT name
|
||||
; in: eax = cluster
|
||||
; in: bx = 0
|
||||
; out: if found: CF=0, es:di -> directory entry
|
||||
; out: if not found: CF=1
|
||||
; push 0x8000
|
||||
; pop es
|
||||
; read current cluster: first cluster goes to 8000:0000, others - to 8200:0000
|
||||
mov es, [bp-7C00h + curseg]
|
||||
push es
|
||||
push eax
|
||||
call read_cluster
|
||||
mov ax, es
|
||||
cmp ah, 82h
|
||||
jb @f
|
||||
mov ax, 8200h
|
||||
@@:
|
||||
mov [bp-7C00h + curseg], ax
|
||||
pop eax
|
||||
pop es
|
||||
; scan for filename
|
||||
shl cx, 4
|
||||
xor di, di
|
||||
sloop:
|
||||
cmp byte [es:di], bl
|
||||
jz snotfound
|
||||
test byte [es:di+11], 8 ; volume label?
|
||||
jnz scont ; ignore volume labels
|
||||
pusha
|
||||
mov cx, 11
|
||||
repz cmpsb
|
||||
popa
|
||||
jz sdone
|
||||
scont:
|
||||
add di, 0x20
|
||||
loop sloop
|
||||
; next cluster
|
||||
push 0x6000
|
||||
pop es
|
||||
push es ax
|
||||
shr eax, 7
|
||||
cmp eax, [bp-14]
|
||||
mov [bp-14], eax
|
||||
jz @f
|
||||
add eax, [bp-6]
|
||||
mov cx, 1
|
||||
call read_sectors32
|
||||
@@:
|
||||
pop di es
|
||||
and di, 0x7F
|
||||
shl di, 2
|
||||
and byte [es:di+3], 0x0F
|
||||
mov eax, [es:di]
|
||||
;and eax, 0x0FFFFFFF
|
||||
cmp eax, 0x0FFFFFF7
|
||||
jb lookup_in_dir
|
||||
snotfound:
|
||||
stc
|
||||
sdone:
|
||||
ret
|
||||
|
||||
out_string:
|
||||
; in: ds:si -> ASCIIZ string
|
||||
lodsb
|
||||
test al, al
|
||||
jz sdone
|
||||
mov ah, 0Eh
|
||||
mov bx, 7
|
||||
int 10h
|
||||
jmp out_string
|
||||
|
||||
aReadError db 'Read error',0
|
||||
if use_lba
|
||||
aNoLBA db 'The drive does not support LBA!',0
|
||||
end if
|
||||
aLoaderNotFound db 'Loader not found',0
|
||||
aPressAnyKey db 13,10,'Press any key...',13,10,0
|
||||
main_loader db 'KORDLDR F32'
|
||||
|
||||
db 56h
|
||||
; just to make file 512 bytes long :)
|
||||
db 'd' xor 'i' xor 'a' xor 'm' xor 'o' xor 'n' xor 'd'
|
||||
|
||||
; bootsector signature
|
||||
dw 0xAA55
|
||||
|
||||
; display offsets of all procedures used by kordldr.f12.asm
|
||||
macro show [procedure]
|
||||
{
|
||||
bits = 16
|
||||
display `procedure,' = '
|
||||
repeat bits/4
|
||||
d = '0' + procedure shr (bits - %*4) and 0Fh
|
||||
if d > '9'
|
||||
d = d + 'A'-'9'-1
|
||||
end if
|
||||
display d
|
||||
end repeat
|
||||
display 13,10
|
||||
}
|
||||
|
||||
show read_sectors32, read_sectors2, err_, noloader
|
||||
; Copyright (c) 2008-2009, diamond
|
||||
; All rights reserved.
|
||||
;
|
||||
; Redistribution and use in source and binary forms, with or without
|
||||
; modification, are permitted provided that the following conditions are met:
|
||||
; * Redistributions of source code must retain the above copyright
|
||||
; notice, this list of conditions and the following disclaimer.
|
||||
; * Redistributions in binary form must reproduce the above copyright
|
||||
; notice, this list of conditions and the following disclaimer in the
|
||||
; documentation and/or other materials provided with the distribution.
|
||||
; * Neither the name of the <organization> nor the
|
||||
; names of its contributors may be used to endorse or promote products
|
||||
; derived from this software without specific prior written permission.
|
||||
;
|
||||
; THIS SOFTWARE IS PROVIDED BY Alexey Teplov aka <Lrz> ''AS IS'' AND ANY
|
||||
; EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
||||
; WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
||||
; DISCLAIMED. IN NO EVENT SHALL <copyright holder> BE LIABLE FOR ANY
|
||||
; DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
||||
; (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
||||
; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
||||
; ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
||||
; (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
||||
; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||||
;*****************************************************************************
|
||||
|
||||
use_lba = 0
|
||||
org 0x7C00
|
||||
jmp start
|
||||
nop
|
||||
; FAT parameters, BPB
|
||||
; they must be changed at install, replaced with real values
|
||||
rb 8 ; BS_OEMName, ignored
|
||||
dw 200h ; BPB_BytsPerSec
|
||||
BPB_SecsPerClus db ?
|
||||
BPB_RsvdSecCnt dw ?
|
||||
BPB_NumFATs db ?
|
||||
BPB_RootEntCnt dw ?
|
||||
dw ? ; BPB_TotSec16
|
||||
db ? ; BPB_Media
|
||||
dw ? ; BPB_FATSz16 = 0 for FAT32
|
||||
BPB_SecPerTrk dw ?
|
||||
BPB_NumHeads dw ?
|
||||
BPB_HiddSec dd ?
|
||||
dd ? ; BPB_TotSec32
|
||||
BPB_FATSz32 dd ?
|
||||
BPB_ExtFlags dw ?
|
||||
dw ? ; BPB_FSVer
|
||||
BPB_RootClus dd ?
|
||||
dw ? ; BPB_FSInfo
|
||||
BPB_BkBootSec dw ?
|
||||
rb 12 ; BPB_Reserved
|
||||
BS_DrvNum db ?
|
||||
db ? ; BS_Reserved1
|
||||
db ? ; BS_BootSig
|
||||
dd ? ; BS_VolID
|
||||
rb 11 ; BS_VolLab
|
||||
rb 8 ;
|
||||
|
||||
curseg dw 0x8000
|
||||
|
||||
start:
|
||||
xor ax, ax
|
||||
mov ss, ax
|
||||
mov sp, 0x7C00
|
||||
mov ds, ax
|
||||
mov bp, sp
|
||||
cld
|
||||
sti
|
||||
push dx ; byte [bp-2] = boot drive
|
||||
if use_lba
|
||||
mov ah, 41h
|
||||
mov bx, 55AAh
|
||||
int 13h
|
||||
mov si, aNoLBA
|
||||
jc err_
|
||||
cmp bx, 0AA55h
|
||||
jnz err_
|
||||
test cl, 1
|
||||
jz err_
|
||||
else
|
||||
mov ah, 8
|
||||
int 13h
|
||||
jc @f
|
||||
movzx ax, dh
|
||||
inc ax
|
||||
mov [bp+BPB_NumHeads-0x7C00], ax
|
||||
and cx, 3Fh
|
||||
mov [bp+BPB_SecPerTrk-0x7C00], cx
|
||||
@@:
|
||||
end if
|
||||
; get FAT parameters
|
||||
xor bx, bx
|
||||
movzx eax, [bp+BPB_NumFATs-0x7C00]
|
||||
mul [bp+BPB_FATSz32-0x7C00]
|
||||
movzx ecx, [bp+BPB_RsvdSecCnt-0x7C00]
|
||||
push ecx ; FAT start = dword [bp-6]
|
||||
add eax, ecx
|
||||
push eax ; data start = dword [bp-10]
|
||||
;push dword -1 ; dword [bp-14] = current sector for FAT cache
|
||||
db 66h
|
||||
push -1 ; dword [bp-14] = current sector for FAT cache
|
||||
mov eax, [bp+BPB_RootClus-0x7C00]
|
||||
mov si, main_loader
|
||||
call lookup_in_dir
|
||||
jnc kordldr_ok
|
||||
noloader:
|
||||
mov si, aLoaderNotFound
|
||||
err_:
|
||||
call out_string
|
||||
mov si, aPressAnyKey
|
||||
call out_string
|
||||
xor ax, ax
|
||||
int 16h
|
||||
int 18h
|
||||
jmp $
|
||||
kordldr_ok:
|
||||
mov eax, [es:di+20-2] ; hiword(eax) = hiword(cluster)
|
||||
mov ax, [es:di+26] ; loword(eax) = loword(cluster)
|
||||
mov es, bx ; es = 0
|
||||
mov bx, 0x7E00
|
||||
push bx ; save return address: bx = 7E00
|
||||
; fall through - 'ret' in read_cluster will return to 7E00
|
||||
|
||||
read_cluster:
|
||||
; ss:bp = 0:7C00
|
||||
; es:bx = pointer to data
|
||||
; eax = cluster
|
||||
sub eax, 2
|
||||
movzx ecx, [bp+BPB_SecsPerClus-0x7C00]
|
||||
mul ecx
|
||||
|
||||
read_sectors2:
|
||||
; same as read_sectors32, but eax is relative to start of data
|
||||
add eax, [bp-10]
|
||||
read_sectors32:
|
||||
; ss:bp = 0:7C00
|
||||
; es:bx = pointer to data
|
||||
; eax = first sector
|
||||
; cx = number of sectors
|
||||
; some high words of 32-bit registers are destroyed!
|
||||
pusha
|
||||
add eax, [bp+BPB_HiddSec-0x7C00]
|
||||
if use_lba
|
||||
push ds
|
||||
do_read_sectors:
|
||||
push ax
|
||||
push cx
|
||||
cmp cx, 0x7F
|
||||
jbe @f
|
||||
mov cx, 0x7F
|
||||
@@:
|
||||
; create disk address packet on the stack
|
||||
; dq starting LBA
|
||||
push 0
|
||||
push 0
|
||||
push eax
|
||||
; dd buffer
|
||||
push es
|
||||
push bx
|
||||
; dw number of blocks to transfer (no more than 0x7F)
|
||||
push cx
|
||||
; dw packet size in bytes
|
||||
push 10h
|
||||
; issue BIOS call
|
||||
push ss
|
||||
pop ds
|
||||
mov si, sp
|
||||
mov dl, [bp-2]
|
||||
mov ah, 42h
|
||||
int 13h
|
||||
mov si, aReadError
|
||||
jc err_
|
||||
; restore stack
|
||||
add sp, 10h
|
||||
; increase current sector & buffer; decrease number of sectors
|
||||
movzx esi, cx
|
||||
mov ax, es
|
||||
shl cx, 5
|
||||
add ax, cx
|
||||
mov es, ax
|
||||
pop cx
|
||||
pop ax
|
||||
add eax, esi
|
||||
sub cx, si
|
||||
jnz do_read_sectors
|
||||
pop ds
|
||||
popa
|
||||
ret
|
||||
else
|
||||
do_read_sectors:
|
||||
pusha
|
||||
pop edi ; loword(edi) = di, hiword(edi) = si
|
||||
push bx
|
||||
|
||||
; eax / (SectorsPerTrack) -> eax, remainder bx
|
||||
movzx esi, [bp+BPB_SecPerTrk-0x7C00]
|
||||
xor edx, edx
|
||||
div esi
|
||||
mov bx, dx ; bx=sector-1
|
||||
|
||||
; eax -> dx:ax
|
||||
push eax
|
||||
pop ax
|
||||
pop dx
|
||||
; (dword in dx:ax) / (NumHeads) -> (word in ax), remainder dx
|
||||
div [bp+BPB_NumHeads-0x7C00]
|
||||
|
||||
; number of sectors: read no more than to end of track
|
||||
sub si, bx
|
||||
cmp cx, si
|
||||
jbe @f
|
||||
mov cx, si
|
||||
@@:
|
||||
|
||||
inc bx
|
||||
; now ax=track, dl=head, dh=0, cl=number of sectors, ch=0, bl=sector; convert to int13 format
|
||||
movzx edi, cx
|
||||
mov dh, dl
|
||||
mov dl, [bp-2]
|
||||
shl ah, 6
|
||||
mov ch, al
|
||||
mov al, cl
|
||||
mov cl, bl
|
||||
or cl, ah
|
||||
pop bx
|
||||
mov si, 3
|
||||
mov ah, 2
|
||||
@@:
|
||||
push ax
|
||||
int 13h
|
||||
jnc @f
|
||||
xor ax, ax
|
||||
int 13h ; reset drive
|
||||
pop ax
|
||||
dec si
|
||||
jnz @b
|
||||
mov si, aReadError
|
||||
jmp err_
|
||||
@@:
|
||||
pop ax
|
||||
mov ax, es
|
||||
mov cx, di
|
||||
shl cx, 5
|
||||
add ax, cx
|
||||
mov es, ax
|
||||
push edi
|
||||
popa
|
||||
add eax, edi
|
||||
sub cx, di
|
||||
jnz do_read_sectors
|
||||
popa
|
||||
ret
|
||||
end if
|
||||
|
||||
lookup_in_dir:
|
||||
; in: ds:si -> 11-bytes FAT name
|
||||
; in: eax = cluster
|
||||
; in: bx = 0
|
||||
; out: if found: CF=0, es:di -> directory entry
|
||||
; out: if not found: CF=1
|
||||
; push 0x8000
|
||||
; pop es
|
||||
; read current cluster: first cluster goes to 8000:0000, others - to 8200:0000
|
||||
mov es, [bp-7C00h + curseg]
|
||||
push es
|
||||
push eax
|
||||
call read_cluster
|
||||
mov ax, es
|
||||
cmp ah, 82h
|
||||
jb @f
|
||||
mov ax, 8200h
|
||||
@@:
|
||||
mov [bp-7C00h + curseg], ax
|
||||
pop eax
|
||||
pop es
|
||||
; scan for filename
|
||||
shl cx, 4
|
||||
xor di, di
|
||||
sloop:
|
||||
cmp byte [es:di], bl
|
||||
jz snotfound
|
||||
test byte [es:di+11], 8 ; volume label?
|
||||
jnz scont ; ignore volume labels
|
||||
pusha
|
||||
mov cx, 11
|
||||
repz cmpsb
|
||||
popa
|
||||
jz sdone
|
||||
scont:
|
||||
add di, 0x20
|
||||
loop sloop
|
||||
; next cluster
|
||||
push 0x6000
|
||||
pop es
|
||||
push es ax
|
||||
shr eax, 7
|
||||
cmp eax, [bp-14]
|
||||
mov [bp-14], eax
|
||||
jz @f
|
||||
add eax, [bp-6]
|
||||
mov cx, 1
|
||||
call read_sectors32
|
||||
@@:
|
||||
pop di es
|
||||
and di, 0x7F
|
||||
shl di, 2
|
||||
and byte [es:di+3], 0x0F
|
||||
mov eax, [es:di]
|
||||
;and eax, 0x0FFFFFFF
|
||||
cmp eax, 0x0FFFFFF7
|
||||
jb lookup_in_dir
|
||||
snotfound:
|
||||
stc
|
||||
sdone:
|
||||
ret
|
||||
|
||||
out_string:
|
||||
; in: ds:si -> ASCIIZ string
|
||||
lodsb
|
||||
test al, al
|
||||
jz sdone
|
||||
mov ah, 0Eh
|
||||
mov bx, 7
|
||||
int 10h
|
||||
jmp out_string
|
||||
|
||||
aReadError db 'Read error',0
|
||||
if use_lba
|
||||
aNoLBA db 'The drive does not support LBA!',0
|
||||
end if
|
||||
aLoaderNotFound db 'Loader not found',0
|
||||
aPressAnyKey db 13,10,'Press any key...',13,10,0
|
||||
main_loader db 'KORDLDR F32'
|
||||
|
||||
db 56h
|
||||
; just to make file 512 bytes long :)
|
||||
db 'd' xor 'i' xor 'a' xor 'm' xor 'o' xor 'n' xor 'd'
|
||||
|
||||
; bootsector signature
|
||||
dw 0xAA55
|
||||
|
||||
; display offsets of all procedures used by kordldr.f12.asm
|
||||
macro show [procedure]
|
||||
{
|
||||
bits = 16
|
||||
display `procedure,' = '
|
||||
repeat bits/4
|
||||
d = '0' + procedure shr (bits - %*4) and 0Fh
|
||||
if d > '9'
|
||||
d = d + 'A'-'9'-1
|
||||
end if
|
||||
display d
|
||||
end repeat
|
||||
display 13,10
|
||||
}
|
||||
|
||||
show read_sectors32, read_sectors2, err_, noloader
|
||||
|
||||
Reference in New Issue
Block a user