| 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 |