0,0 → 1,344 |
;************************************************************* |
;* 28.01.2006 find all Fat16/32 partition in all input point * |
;* to MBR - Mario79 * |
;************************************************************* |
|
align 4 |
;****************************************************** |
; Please do not change this place - variables in text |
; Mario79 |
; START place |
;****************************************************** |
PARTITION_START dd 0x3f |
PARTITION_END dd 0 |
SECTORS_PER_FAT dd 0x1f3a |
NUMBER_OF_FATS dd 0x2 |
SECTORS_PER_CLUSTER dd 0x8 |
BYTES_PER_SECTOR dd 0x200 ; Note: if BPS <> 512 need lots of changes |
ROOT_CLUSTER dd 2 ; first rootdir cluster |
FAT_START dd 0 ; start of fat table |
ROOT_START dd 0 ; start of rootdir (only fat16) |
ROOT_SECTORS dd 0 ; count of rootdir sectors (only fat16) |
DATA_START dd 0 ; start of data area (=first cluster 2) |
LAST_CLUSTER dd 0 ; last availabe cluster |
ADR_FSINFO dd 0 ; used only by fat32 |
|
fatRESERVED dd 0x0FFFFFF6 |
fatBAD dd 0x0FFFFFF7 |
fatEND dd 0x0FFFFFF8 |
fatMASK dd 0x0FFFFFFF |
|
fat_type db 0 ; 0=none, 16=fat16, 32=fat32 |
;*************************************************************************** |
; End place |
; Mario79 |
;*************************************************************************** |
|
iglobal |
partition_types: ; list of fat16/32 partitions |
db 0x04 ; DOS: fat16 <32M |
db 0x06 ; DOS: fat16 >32M |
db 0x0b ; WIN95: fat32 |
db 0x0c ; WIN95: fat32, LBA-mapped |
db 0x0e ; WIN95: fat16, LBA-mapped |
db 0x14 ; Hidden DOS: fat16 <32M |
db 0x16 ; Hidden DOS: fat16 >32M |
db 0x1b ; Hidden WIN95: fat32 |
db 0x1c ; Hidden WIN95: fat32, LBA-mapped |
db 0x1e ; Hidden WIN95: fat16, LBA-mapped |
db 0xc4 ; DRDOS/secured: fat16 <32M |
db 0xc6 ; DRDOS/secured: fat16 >32M |
db 0xcb ; DRDOS/secured: fat32 |
db 0xcc ; DRDOS/secured: fat32, LBA-mapped |
db 0xce ; DRDOS/secured: fat16, LBA-mapped |
db 0xd4 ; Old Multiuser DOS secured: fat16 <32M |
db 0xd6 ; Old Multiuser DOS secured: fat16 >32M |
partition_types_end: |
|
|
extended_types: ; list of extended partitions |
db 0x05 ; DOS: extended partition |
db 0x0f ; WIN95: extended partition, LBA-mapped |
db 0xc5 ; DRDOS/secured: extended partition |
db 0xd5 ; Old Multiuser DOS secured: extended partition |
extended_types_end: |
|
endg |
|
; Partition chain used: |
; MBR ; PARTITION2 ; PARTITION3 ; PARTITION4 |
;========================================================== |
; fat16/32 +-- fat16/32 +-- fat16/32 +-- fat16/32 +-- |
; extended --+ extended --+ extended --+ extended --+ |
; 0 0 0 0 |
; 0 0 0 0 |
; Notes: |
; - extended partition need to be in second entry on table |
; - it will skip over removed partitions |
|
set_FAT32_variables: |
mov [0xfe10],dword 0 ; entries in hd cache |
mov [problem_partition],0 |
call reserve_hd1 |
call clear_hd_cache |
|
cmp dword [hdpos],0 |
je problem_hd |
|
pushad |
xor ecx,ecx ; partition count |
mov edx,-1 ; flag for partition |
xor eax,eax ; read MBR |
xor ebp,ebp ; extended partition start |
|
new_partition: |
test ebp,ebp ; is there extended partition? |
jnz extended_already_set ; yes |
xchg ebp,eax ; no. set it now |
|
extended_already_set: |
add eax,ebp ; mbr=mbr+0, ext_part=ext_start+relat_start |
mov ebx,buffer |
call hd_read |
|
cmp word [ebx+0x1fe],0xaa55 ; is it valid boot sector? |
jnz end_partition_chain |
cmp dword [ebx+0x1be+0xc],0 ; skip over empty partition |
jz next_partition |
|
push eax |
mov al,[ebx+0x1be+4] ; get primary partition type |
call scan_partition_types |
pop eax |
jnz next_primary_partition ; no. skip over |
|
inc ecx |
cmp ecx,[fat32part] ; is it wanted partition? |
jnz next_primary_partition ; no |
|
mov edx,eax ; start sector |
add edx,[ebx+0x1be+8] ; add relative start |
|
next_primary_partition: |
push eax |
mov al,[ebx+0x1be+4+16] ; get primary partition type |
call scan_partition_types |
pop eax |
jnz next_primary_partition_1 ; no. skip over |
|
inc ecx |
cmp ecx,[fat32part] ; is it wanted partition? |
jnz next_primary_partition_1 ; no |
|
mov edx,eax ; start sector |
add edx,[ebx+0x1be+8+16] ; add relative start |
|
next_primary_partition_1: |
push eax |
mov al,[ebx+0x1be+4+16+16] ; get primary partition type |
call scan_partition_types |
pop eax |
jnz next_primary_partition_2 ; no. skip over |
|
inc ecx |
cmp ecx,[fat32part] ; is it wanted partition? |
jnz next_primary_partition_2 ; no |
|
mov edx,eax ; start sector |
add edx,[ebx+0x1be+8+16+16] ; add relative start |
|
next_primary_partition_2: |
push eax |
mov al,[ebx+0x1be+4+16+16+16] ; get primary partition type |
call scan_partition_types |
pop eax |
jnz next_partition ; no. skip over |
|
inc ecx |
cmp ecx,[fat32part] ; is it wanted partition? |
jnz next_partition ; no |
|
mov edx,eax ; start sector |
add edx,[ebx+0x1be+8+16+16+16] ; add relative start |
|
next_partition: |
push eax |
mov al,[ebx+0x1be+4] ; get extended partition type |
call scan_extended_types |
pop eax |
jnz next_partition_1 |
|
mov eax,[ebx+0x1be+8] ; add relative start |
test eax,eax ; is there extended partition? |
jnz new_partition ; yes. read it |
|
next_partition_1: |
push eax |
mov al,[ebx+0x1be+4+16] ; get extended partition type |
call scan_extended_types |
pop eax |
jnz next_partition_2 |
|
mov eax,[ebx+0x1be+8+16] ; add relative start |
test eax,eax ; is there extended partition? |
jnz new_partition ; yes. read it |
|
next_partition_2: |
push eax |
mov al,[ebx+0x1be+4+16+16] ; get extended partition type |
call scan_extended_types |
pop eax |
jnz next_partition_3 |
|
mov eax,[ebx+0x1be+8+16+16] ; add relative start |
test eax,eax ; is there extended partition? |
jnz new_partition ; yes. read it |
|
next_partition_3: |
push eax |
mov al,[ebx+0x1be+4+16+16+16] ; get extended partition type |
call scan_extended_types |
pop eax |
jnz end_partition_chain ; no. end chain |
|
mov eax,[ebx+0x1be+8+16+16+16] ; get start of extended partition |
test eax,eax ; is there extended partition? |
jnz new_partition ; yes. read it |
|
end_partition_chain: |
mov [partition_count],ecx |
|
cmp edx,-1 ; found wanted partition? |
jnz hd_and_partition_ok ; yes. install it |
jmp problem_partition_or_fat |
|
scan_partition_types: |
push ecx |
mov edi,partition_types |
mov ecx,partition_types_end-partition_types |
cld |
repne scasb ; is partition type ok? |
pop ecx |
ret |
|
scan_extended_types: |
push ecx |
mov edi,extended_types |
mov ecx,extended_types_end-extended_types |
cld |
repne scasb ; is it extended partition? |
pop ecx |
ret |
|
problem_fat_dec_count: ; bootsector is missing or another problem |
dec [partition_count] ; remove it from partition_count |
|
problem_partition_or_fat: |
popad |
|
problem_hd: |
mov [fat_type],0 |
mov [hd1_status],0 ; free |
mov [problem_partition],1 |
ret |
|
hd_and_partition_ok: |
mov eax,edx |
mov [PARTITION_START],eax |
|
mov [hd_setup],1 |
mov ebx,buffer |
call hd_read ; read boot sector of partition |
mov [hd_setup],0 |
|
cmp word [ebx+0x1fe],0xaa55 ; is it valid boot sector? |
jnz problem_fat_dec_count |
|
movzx eax,word [ebx+0xe] ; sectors reserved |
add eax,[PARTITION_START] |
mov [FAT_START],eax ; fat_start = partition_start + reserved |
|
movzx eax,byte [ebx+0xd] ; sectors per cluster |
mov [SECTORS_PER_CLUSTER],eax |
|
movzx ecx,word [ebx+0xb] ; bytes per sector |
mov [BYTES_PER_SECTOR],ecx |
|
movzx eax,word [ebx+0x11] ; count of rootdir entries (=0 fat32) |
mov edx,32 |
mul edx |
dec ecx |
add eax,ecx ; round up if not equal count |
inc ecx ; bytes per sector |
div ecx |
mov [ROOT_SECTORS],eax ; count of rootdir sectors |
|
movzx eax,word [ebx+0x16] ; sectors per fat <65536 |
test eax,eax |
jnz fat16_fatsize |
mov eax,[ebx+0x24] ; sectors per fat |
fat16_fatsize: |
mov [SECTORS_PER_FAT],eax |
|
movzx eax,byte [ebx+0x10] ; number of fats |
test eax,eax ; if 0 it's not fat partition |
jz problem_fat_dec_count |
mov [NUMBER_OF_FATS],eax |
imul eax,[SECTORS_PER_FAT] |
add eax,[FAT_START] |
mov [ROOT_START],eax ; rootdir = fat_start + fat_size * fat_count |
add eax,[ROOT_SECTORS] ; rootdir sectors should be 0 on fat32 |
mov [DATA_START],eax ; data area = rootdir + rootdir_size |
|
movzx eax,word [ebx+0x13] ; total sector count <65536 |
test eax,eax |
jnz fat16_total |
mov eax,[ebx+0x20] ; total sector count |
fat16_total: |
add eax,[PARTITION_START] |
dec eax |
mov [PARTITION_END],eax |
inc eax |
sub eax,[DATA_START] ; eax = count of data sectors |
xor edx,edx |
div dword [SECTORS_PER_CLUSTER] |
inc eax |
mov [LAST_CLUSTER],eax |
dec eax ; cluster count |
|
; limits by Microsoft Hardware White Paper v1.03 |
cmp eax,4085 ; 0xff5 |
jb problem_fat_dec_count ; fat12 not supported |
cmp eax,65525 ; 0xfff5 |
jb fat16_partition |
|
fat32_partition: |
mov eax,[ebx+0x2c] ; rootdir cluster |
mov [ROOT_CLUSTER],eax |
movzx eax,word [ebx+0x30] ; fs info sector |
add eax,[PARTITION_START] |
mov [ADR_FSINFO],eax |
|
popad |
|
mov [fatRESERVED],0x0FFFFFF6 |
mov [fatBAD],0x0FFFFFF7 |
mov [fatEND],0x0FFFFFF8 |
mov [fatMASK],0x0FFFFFFF |
mov [fat_type],32 ; Fat32 |
mov [hd1_status],0 ; free |
ret |
|
fat16_partition: |
xor eax,eax |
mov [ROOT_CLUSTER],eax |
|
popad |
|
mov [fatRESERVED],0x0000FFF6 |
mov [fatBAD],0x0000FFF7 |
mov [fatEND],0x0000FFF8 |
mov [fatMASK],0x0000FFFF |
mov [fat_type],16 ; Fat16 |
mov [hd1_status],0 ; free |
ret |