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;; ;;
;; Contains ext2 structures, and macros. ;;
;; ;;
;; Copyright (C) KolibriOS team 2013-2014. All rights reserved. ;;
;; Distributed under terms of the GNU General Public License ;;
;; ;;
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$Revision: 4891 $
; Future jobs for driver, in order of preference:
; * clean up existing extents support.
; * add b-tree directories support.
; * add long file support.
; * add journal support.
; * add minor features that come with ext3/4.
; Recommended move to some kernel-wide bitmap handling code (with a bit of abstraction, of course).
;---------------------------------------------------------------------
; Clears a bit.
; Input: eax = index into bitmap.
; [EXTFS.ext2_save_block] = address of bitmap.
; ebp = address of EXTFS.
; Output: Bit cleared.
; eax = non-zero, if already cleared.
;---------------------------------------------------------------------
bitmap_clear_bit:
push ebx ecx edx
xor edx, edx
mov ecx, 8
div ecx
add eax, [ebp + EXTFS.ext2_save_block]
; Get the mask.
mov ebx, 1
mov ecx, edx
shl ebx, cl
test [eax], ebx
jz .cleared
not ebx
and [eax], ebx
xor eax, eax
.return:
pop edx ecx ebx
ret
; Already cleared.
.cleared:
xor eax, eax
not eax
jmp .return
;---------------------------------------------------------------------
; Finds free bit in the bitmap.
; Input: ecx = number of bits in the bitmap.
; [EXTFS.ext2_save_block] = address of bitmap.
; ebp = address of EXTFS.
; Output: eax = index of free bit in the bitmap; marked set.
; 0xFFFFFFFF if no free bit found.
;---------------------------------------------------------------------
ext2_find_free_bit:
bitmap_find_free_bit:
push esi ebx ecx edx
mov esi, [ebp + EXTFS.ext2_save_block]
; Get total DWORDS in eax; total bits in last dword, if any, in edx.
xor edx, edx
mov eax, ecx
mov ecx, 32
div ecx
mov ecx, eax
xor eax, eax
push edx
test ecx, ecx
jz .last_bits
; Check in the DWORDS.
.dwords:
mov ebx, [esi]
not ebx
bsf edx, ebx
; If 0, then the original value would be 0xFFFFFFFF, hence no free bits.
jz @F
; We found the value. Let's return with it.
add esp, 4
add eax, edx
jmp .return
@@:
add esi, 4
add eax, 32
loop .dwords
.last_bits:
; Check in the last few bits.
pop ecx
test ecx, ecx
jz @F
mov ebx, [esi]
not ebx
bsf ebx, edx
; If 0, no free bits.
jz @F
; If free bit is greater than the last known bit, then error.
cmp edx, ecx
jg @F
add eax, edx
jmp .return
@@:
; Didn't find any free bits.
xor eax, eax
not eax
jmp @F
.return:
mov ecx, edx
mov edx, 1
shl edx, cl
or [esi], edx
@@:
pop edx ecx ebx esi
ret
; Recommended move to some kernel-wide string handling code.
;---------------------------------------------------------------------
; Find the length of a string.
; Input: esi = source.
; Output: length in ecx
;---------------------------------------------------------------------
strlen:
push eax esi
xor ecx, ecx
@@:
lodsb
test al, al
jz .ret
inc ecx
jmp @B
.ret:
pop esi eax
ret
;---------------------------------------------------------------------
; Convert UTF-8 string to ASCII-string (codepage 866)
; Input: esi = source.
; edi = buffer.
; ecx = length of source.
; Output: destroys eax, esi, edi
;---------------------------------------------------------------------
utf8_to_cp866:
; Check for zero-length string.
jecxz .return
.start:
lodsw
cmp al, 0x80
jb .ascii
xchg al, ah ; Big-endian.
cmp ax, 0xd080
jz .yo1
cmp ax, 0xd191
jz .yo2
cmp ax, 0xd090
jb .unk
cmp ax, 0xd180
jb .rus1
cmp ax, 0xd190
jb .rus2
.unk:
mov al, '_'
jmp .doit
.yo1:
mov al, 0xf0 ; Ё capital.
jmp .doit
.yo2:
mov al, 0xf1 ; ё small.
jmp .doit
.rus1:
sub ax, 0xd090 - 0x80
jmp .doit
.rus2:
sub ax, 0xd18f - 0xEF
.doit:
stosb
sub ecx, 2
ja .start
ret
.ascii:
stosb
dec esi
dec ecx
jnz .start
.return:
ret
; Recommended move to some kernel-wide time handling code.
; Total cumulative seconds till each month.
cumulative_seconds_in_month:
.january: dd 0 * (60 * 60 * 24)
.february: dd 31 * (60 * 60 * 24)
.march: dd 59 * (60 * 60 * 24)
.april: dd 90 * (60 * 60 * 24)
.may: dd 120 * (60 * 60 * 24)
.june: dd 151 * (60 * 60 * 24)
.july: dd 181 * (60 * 60 * 24)
.august: dd 212 * (60 * 60 * 24)
.september: dd 243 * (60 * 60 * 24)
.october: dd 273 * (60 * 60 * 24)
.november: dd 304 * (60 * 60 * 24)
.december: dd 334 * (60 * 60 * 24)
current_bdfe_time:
dd 0
current_bdfe_date:
dd 0
;---------------------------------------------------------------------
; Stores current unix time.
; Input: edi = buffer to output Unix time.
;---------------------------------------------------------------------
current_unix_time:
push eax esi
mov esi, current_bdfe_time
; Just a small observation:
; The CMOS is a pretty bad source to get time from. One shouldn't rely on it,
; since it messes up the time by tiny bits. Of course, this is all technical,
; but one can look it up on the osdev wiki. What is better is to get the time
; from CMOS during boot, then update system time using a more accurate timer.
; I'll probably add that after the Summer of Code, so TODO! TODO! TODO!.
; Get time from CMOS.
; Seconds.
mov al, 0x00
out 0x70, al
in al, 0x71
call bcd2bin
mov [esi + 0], al
; Minute.
mov al, 0x02
out 0x70, al
in al, 0x71
call bcd2bin
mov [esi + 1], al
; Hour.
mov al, 0x04
out 0x70, al
in al, 0x71
call bcd2bin
mov [esi + 2], al
; Get date.
; Day.
mov al, 0x7
out 0x70, al
in al, 0x71
call bcd2bin
mov [esi + 4], al
; Month.
mov al, 0x8
out 0x70, al
in al, 0x71
call bcd2bin
mov [esi + 5], al
; Year.
mov al, 0x9
out 0x70, al
in al, 0x71
call bcd2bin
add ax, 2000 ; CMOS only returns last two digits.
; Note that everywhere in KolibriOS this is used.
; This is hacky, since the RTC can be incorrectly set
; to something before 2000.
mov [esi + 6], ax
call bdfe_to_unix_time
pop esi eax
ret
;---------------------------------------------------------------------
; Convert time+date from BDFE to Unix time.
; Input: esi = pointer to BDFE time+date.
; edi = buffer to output Unix time.
;---------------------------------------------------------------------
bdfe_to_unix_time:
push eax ebx ecx edx
mov dword[edi], 0x00000000
; The minimum representable time is 1901-12-13.
cmp word[esi + 6], 1901
jb .ret
jg .max
cmp byte[esi + 5], 12
jb .ret
cmp byte[esi + 4], 13
jbe .ret
jg .convert
; Check if it is more than the maximum representable time.
.max:
; The maximum representable time is 2038-01-19.
cmp word[esi + 6], 2038
jg .ret
jb .convert
cmp byte[esi + 5], 1
jg .ret
cmp byte[esi + 4], 19
jge .ret
; Convert the time.
.convert:
; Get if current year is leap year in ECX.
xor ecx, ecx
mov ebx, 4
xor edx, edx
cmp word[esi + 6], 1970
jb .negative
movzx eax, word[esi + 6] ; Year.
cmp byte[esi + 5], 3 ; If the month is less than March, than that year doesn't matter.
jge @F
test eax, 3
; Not a leap year.
jnz @F
inc ecx
@@:
; Number of leap years between two years = ((end date - 1)/4) - (1970/4)
dec eax
div ebx
sub eax, 1970/4
; EAX is the number of leap years.
add eax, ecx
mov ecx, (60 * 60 * 24) ; Seconds in a day.
mul ecx
; Account for leap years, i.e., one day extra for each.
add [edi], eax
; Get total days in EAX.
movzx eax, byte[esi + 4]
dec eax
mul ecx
; Account for days.
add [edi], eax
; Account for month.
movzx eax, byte[esi + 5]
dec eax
mov eax, [cumulative_seconds_in_month + (eax * 4)]
add [edi], eax
; Account for year.
movzx eax, word[esi + 6]
sub eax, 1970
mov ecx, (60 * 60 * 24) * 365 ; Seconds in a year.
mul ecx
add [edi], eax
; Seconds.
movzx eax, byte[esi + 0]
add [edi], eax
; Minutes.
movzx eax, byte[esi + 1]
mov ecx, 60
mul ecx
add [edi], eax
; Hours.
movzx eax, byte[esi + 2]
mov ecx, (60 * 60)
mul ecx
add [edi], eax
; The time wanted is before the epoch; handle it here.
.negative:
; TODO.
.ret:
pop edx ecx ebx eax
ret
; Recommended move to some kernel-wide alloc handling code.
macro KERNEL_ALLOC store, label
{
call kernel_alloc
mov store, eax
test eax, eax
jz label
}
macro KERNEL_FREE data, label
{
cmp data, 0
jz label
push data
call kernel_free
}
struct EXTFS PARTITION
lock MUTEX
partition_flags dd ?
log_block_size dd ?
block_size dd ?
count_block_in_block dd ?
blocks_per_group dd ?
global_desc_table dd ?
root_inode dd ? ; Pointer to root inode in memory.
inode_size dd ?
count_pointer_in_block dd ? ; (block_size / 4)
count_pointer_in_block_square dd ? ; (block_size / 4)**2
ext2_save_block dd ? ; Block for 1 global procedure.
ext2_temp_block dd ? ; Block for small procedures.
ext2_save_inode dd ? ; inode for global procedures.
ext2_temp_inode dd ? ; inode for small procedures.
groups_count dd ?
superblock rd 1024/4
ends
; EXT2 revisions.
EXT2_GOOD_OLD_REV = 0
; For fs_type.
FS_TYPE_UNDEFINED = 0
FS_TYPE_EXT = 2
; Some set inodes.
EXT2_BAD_INO = 1
EXT2_ROOT_INO = 2
EXT2_ACL_IDX_INO = 3
EXT2_ACL_DATA_INO = 4
EXT2_BOOT_LOADER_INO = 5
EXT2_UNDEL_DIR_INO = 6
; EXT2_SUPER_MAGIC.
EXT2_SUPER_MAGIC = 0xEF53
EXT2_VALID_FS = 1
; Flags defining i_mode values.
EXT2_S_IFMT = 0xF000 ; Mask for file type.
EXT2_S_IFREG = 0x8000 ; Regular file.
EXT2_S_IFDIR = 0x4000 ; Directory.
EXT2_S_IRUSR = 0x0100 ; User read
EXT2_S_IWUSR = 0x0080 ; User write
EXT2_S_IXUSR = 0x0040 ; User execute
EXT2_S_IRGRP = 0x0020 ; Group read
EXT2_S_IWGRP = 0x0010 ; Group write
EXT2_S_IXGRP = 0x0008 ; Group execute
EXT2_S_IROTH = 0x0004 ; Others read
EXT2_S_IWOTH = 0x0002 ; Others write
EXT2_S_IXOTH = 0x0001 ; Others execute
PERMISSIONS = EXT2_S_IRUSR or EXT2_S_IWUSR \
or EXT2_S_IRGRP or EXT2_S_IWGRP \
or EXT2_S_IROTH or EXT2_S_IWOTH
; File type defining values in directory entry.
EXT2_FT_REG_FILE = 1 ; Regular file.
EXT2_FT_DIR = 2 ; Directory.
; Flags used by KolibriOS.
FS_FT_HIDDEN = 2
FS_FT_DIR = 0x10 ; Directory.
; ext2 partition flags.
EXT2_RO = 0x01
FS_FT_ASCII = 0 ; Name in ASCII.
FS_FT_UNICODE = 1 ; Name in Unicode.
EXT2_FEATURE_INCOMPAT_FILETYPE = 0x0002 ; Have file type in directory entry.
EXT4_FEATURE_INCOMPAT_EXTENTS = 0x0040 ; Extents.
EXT4_FEATURE_INCOMPAT_FLEX_BG = 0x0200 ; Flexible block groups.
EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER = 0x0001 ; Sparse Superblock
EXT2_FEATURE_RO_COMPAT_LARGE_FILE = 0x0002 ; Large file support (64-bit file size)
; Implemented ext[2,3,4] features.
EXT4_FEATURE_INCOMPAT_SUPP = EXT2_FEATURE_INCOMPAT_FILETYPE \
or EXT4_FEATURE_INCOMPAT_EXTENTS \
or EXT4_FEATURE_INCOMPAT_FLEX_BG
; Implemented features which otherwise require "read-only" mount.
EXT2_FEATURE_RO_COMPAT_SUPP = EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER \
or EXT2_FEATURE_RO_COMPAT_LARGE_FILE
; ext4 features not support for write.
EXT4_FEATURE_INCOMPAT_W_NOT_SUPP = EXT4_FEATURE_INCOMPAT_EXTENTS \
or EXT4_FEATURE_INCOMPAT_FLEX_BG
; Flags specified in i_flags.
EXT2_EXTENTS_FL = 0x00080000 ; Extents.
struct EXT2_INODE_STRUC
i_mode dw ?
i_uid dw ?
i_size dd ?
i_atime dd ?
i_ctime dd ?
i_mtime dd ?
i_dtime dd ?
i_gid dw ?
i_links_count dw ?
i_blocks dd ?
i_flags dd ?
i_osd1 dd ?
i_block rd 15
i_generation dd ?
i_file_acl dd ?
i_dir_acl dd ?
i_faddr dd ?
i_osd2 dd ? ; 12 bytes.
ends
struct EXT2_DIR_STRUC
inode dd ?
rec_len dw ?
name_len db ?
file_type db ?
name db ? ; 255 (max) bytes.
ends
struct EXT2_BLOCK_GROUP_DESC
block_bitmap dd ? ; +0
inode_bitmap dd ? ; +4
inode_table dd ? ; +8
free_blocks_count dw ? ; +12
free_inodes_count dw ? ; +14
used_dirs_count dw ? ; +16
pad dw ? ; +18
reserved rb 12 ; +20
ends
struct EXT2_SB_STRUC
inodes_count dd ? ; +0
blocks_count dd ? ; +4
r_block_count dd ? ; +8
free_block_count dd ? ; +12
free_inodes_count dd ? ; +16
first_data_block dd ? ; +20
log_block_size dd ? ; +24
log_frag_size dd ? ; +28
blocks_per_group dd ? ; +32
frags_per_group dd ? ; +36
inodes_per_group dd ? ; +40
mtime dd ? ; +44
wtime dd ? ; +48
mnt_count dw ? ; +52
max_mnt_count dw ? ; +54
magic dw ? ; +56
state dw ? ; +58
errors dw ? ; +60
minor_rev_level dw ? ; +62
lastcheck dd ? ; +64
check_intervals dd ? ; +68
creator_os dd ? ; +72
rev_level dd ? ; +76
def_resuid dw ? ; +80
def_resgid dw ? ; +82
first_ino dd ? ; +84
inode_size dw ? ; +88
block_group_nr dw ? ; +90
feature_compat dd ? ; +92
feature_incompat dd ? ; +96
feature_ro_compat dd ? ; +100
uuid rb 16 ; +104
volume_name rb 16 ; +120
last_mounted rb 64 ; +136
algo_bitmap dd ? ; +200
prealloc_blocks db ? ; +204
preallock_dir_blocks db ? ; +205
reserved_gdt_blocks dw ? ; +206
journal_uuid rb 16 ; +208
journal_inum dd ? ; +224
journal_dev dd ? ; +228
last_orphan dd ? ; +232
hash_seed rd 4 ; +236
def_hash_version db ? ; +252
reserved rb 3 ; +253 (reserved)
default_mount_options dd ? ; +256
first_meta_bg dd ? ; +260
mkfs_time dd ? ; +264
jnl_blocks rd 17 ; +268
blocks_count_hi dd ? ; +336
r_blocks_count_hi dd ? ; +340
free_blocks_count_hi dd ? ; +344
min_extra_isize dw ? ; +348
want_extra_isize dw ? ; +350
flags dd ? ; +352
raid_stride dw ? ; +356
mmp_interval dw ? ; +358
mmp_block dq ? ; +360
raid_stripe_width dd ? ; +368
log_groups_per_flex db ? ; +372
ends
; Header block extents.
struct EXT4_EXTENT_HEADER
eh_magic dw ? ; Magic value of 0xF30A, for ext4.
eh_entries dw ? ; Number of blocks covered by the extent.
eh_max dw ? ; Capacity of entries.
eh_depth dw ? ; Tree depth (if 0, extents in the array are not extent indexes)
eh_generation dd ? ; ???
ends
; Extent.
struct EXT4_EXTENT
ee_block dd ? ; First logical block extent covers.
ee_len dw ? ; Number of blocks covered by extent.
ee_start_hi dw ? ; Upper 16 bits of 48-bit address (unused in KOS)
ee_start_lo dd ? ; Lower 32 bits of 48-bit address.
ends
; Index on-disk structure; pointer to block of extents/indexes.
struct EXT4_EXTENT_IDX
ei_block dd ? ; Covers logical blocks from here.
ei_leaf_lo dd ? ; Lower 32-bits of pointer to the physical block of the next level.
ei_leaf_hi dw ? ; Higher 16-bits (unused in KOS).
ei_unused dw ? ; Reserved.
ends