;
; ****************************************************************************
-%ifndef IS_MDSLINUX
%define IS_SYSLINUX 1
-%endif
%include "head.inc"
;
; Some semi-configurable constants... change on your own risk.
;
my_id equ syslinux_id
-FILENAME_MAX_LG2 equ 6 ; log2(Max filename size Including final null)
-FILENAME_MAX equ (1<<FILENAME_MAX_LG2) ; Max mangled filename size
-NULLFILE equ 0 ; First char space == null filename
-NULLOFFSET equ 0 ; Position in which to look
-retry_count equ 16 ; How patient are we with the disk?
-%assign HIGHMEM_SLOP 0 ; Avoid this much memory near the top
-LDLINUX_MAGIC equ 0x3eb202fe ; A random number to identify ourselves with
-
-MAX_OPEN_LG2 equ 6 ; log2(Max number of open files)
-MAX_OPEN equ (1 << MAX_OPEN_LG2)
-
-SECTOR_SHIFT equ 9
-SECTOR_SIZE equ (1 << SECTOR_SHIFT)
-
-DIRENT_SHIFT equ 5
-DIRENT_SIZE equ (1 << DIRENT_SHIFT)
-
-ROOT_DIR_WORD equ 0x002F
-
-;
-; The following structure is used for "virtual kernels"; i.e. LILO-style
-; option labels. The options we permit here are `kernel' and `append
-; Since there is no room in the bottom 64K for all of these, we
-; stick them in high memory and copy them down before we need them.
-;
- struc vkernel
-vk_vname: resb FILENAME_MAX ; Virtual name **MUST BE FIRST!**
-vk_rname: resb FILENAME_MAX ; Real name
-vk_appendlen: resw 1
-vk_type: resb 1 ; Type of file
- alignb 4
-vk_append: resb max_cmd_len+1 ; Command line
- alignb 4
-vk_end: equ $ ; Should be <= vk_size
- endstruc
-
-;
-; File structure. This holds the information for each currently open file.
-;
- struc open_file_t
-file_sector resd 1 ; Sector pointer (0 = structure free)
-file_bytesleft resd 1 ; Number of bytes left
-file_left resd 1 ; Number of sectors left
- resd 1 ; Unused
- endstruc
-
-;
-; Structure for codepage files
-;
- struc cp
-.magic resd 2 ; 8-byte magic number
-.reserved resd 6 ; Reserved for future use
-.uppercase resb 256 ; Internal upper-case table
-.unicode resw 256 ; Unicode matching table
-.unicode_alt resw 256 ; Alternate Unicode matching table
- endstruc
-
-%ifndef DEPEND
-%if (open_file_t_size & (open_file_t_size-1))
-%error "open_file_t is not a power of 2"
-%endif
-%endif
-
-; ---------------------------------------------------------------------------
-; BEGIN CODE
-; ---------------------------------------------------------------------------
-
-;
-; Memory below this point is reserved for the BIOS and the MBR
-;
- section .earlybss
-trackbufsize equ 8192
-trackbuf resb trackbufsize ; Track buffer goes here
- ; ends at 2800h
-
- section .bss16
- alignb 4
-FAT resd 1 ; Location of (first) FAT
-RootDirArea resd 1 ; Location of root directory area
-RootDir resd 1 ; Location of root directory proper
-DataArea resd 1 ; Location of data area
-RootDirSize resd 1 ; Root dir size in sectors
-TotalSectors resd 1 ; Total number of sectors
-ClustSize resd 1 ; Bytes/cluster
-ClustMask resd 1 ; Sectors/cluster - 1
-CopySuper resb 1 ; Distinguish .bs versus .bss
-ClustShift resb 1 ; Shift count for sectors/cluster
-ClustByteShift resb 1 ; Shift count for bytes/cluster
-
- alignb open_file_t_size
-Files resb MAX_OPEN*open_file_t_size
-
-;
-; Common bootstrap code for disk-based derivatives
-;
-%include "diskstart.inc"
-
-;
-; Common initialization code
-;
-%include "init.inc"
-%include "cpuinit.inc"
-
-;
-; Compute some information about this filesystem.
-;
-
-; First, generate the map of regions
-genfatinfo:
- mov edx,[bxSectors]
- and dx,dx
- jnz .have_secs
- mov edx,[bsHugeSectors]
-.have_secs:
- mov [TotalSectors],edx
-
- mov eax,[bxResSectors]
- mov [FAT],eax ; Beginning of FAT
- mov edx,[bxFATsecs]
- and dx,dx
- jnz .have_fatsecs
- mov edx,[bootsec+36] ; FAT32 BPB_FATsz32
-.have_fatsecs:
- imul edx,[bxFATs]
- add eax,edx
- mov [RootDirArea],eax ; Beginning of root directory
- mov [RootDir],eax ; For FAT12/16 == root dir location
-
- mov edx,[bxRootDirEnts]
- add dx,SECTOR_SIZE/32-1
- shr dx,SECTOR_SHIFT-5
- mov [RootDirSize],edx
- add eax,edx
- mov [DataArea],eax ; Beginning of data area
-
-; Next, generate a cluster size shift count and mask
- mov eax,[bxSecPerClust]
- bsr cx,ax
- mov [ClustShift],cl
- push cx
- add cl,SECTOR_SHIFT
- mov [ClustByteShift],cl
- pop cx
- dec ax
- mov [ClustMask],eax
- inc ax
- shl eax,SECTOR_SHIFT
- mov [ClustSize],eax
-
-;
-; FAT12, FAT16 or FAT28^H^H32? This computation is fscking ridiculous.
-;
-getfattype:
- mov eax,[TotalSectors]
- sub eax,[DataArea]
- shr eax,cl ; cl == ClustShift
- mov cl,nextcluster_fat12-(nextcluster+2)
- cmp eax,4085 ; FAT12 limit
- jb .setsize
- mov cl,nextcluster_fat16-(nextcluster+2)
- cmp eax,65525 ; FAT16 limit
- jb .setsize
- ;
- ; FAT32, root directory is a cluster chain
- ;
- mov cl,[ClustShift]
- mov eax,[bootsec+44] ; Root directory cluster
- sub eax,2
- shl eax,cl
- add eax,[DataArea]
- mov [RootDir],eax
- mov cl,nextcluster_fat28-(nextcluster+2)
- mov byte [SuperSize],superblock_len_fat32
-.setsize:
- mov byte [nextcluster+1],cl
-
-
-;
-; Initialize the metadata cache
-;
- call initcache
-
-;
-; Now, everything is "up and running"... patch kaboom for more
-; verbosity and using the full screen system
-;
- ; E9 = JMP NEAR
- mov di,kaboom.patch
- mov al,0e9h
- stosb
- mov ax,kaboom2-2
- sub ax,di
- stosw
-
-;
-; Now we're all set to start with our *real* business. First load the
-; configuration file (if any) and parse it.
-;
-; In previous versions I avoided using 32-bit registers because of a
-; rumour some BIOSes clobbered the upper half of 32-bit registers at
-; random. I figure, though, that if there are any of those still left
-; they probably won't be trying to install Linux on them...
-;
-; The code is still ripe with 16-bitisms, though. Not worth the hassle
-; to take'm out. In fact, we may want to put them back if we're going
-; to boot ELKS at some point.
-;
-
-;
-; Load configuration file
-;
- mov si,config_name ; Save configuration file name
- mov di,ConfigName
- call strcpy
- mov word [CurrentDirName],ROOT_DIR_WORD ; Write '/',0 to the CurrentDirName
-
- mov eax,[RootDir] ; Make the root directory ...
- mov [CurrentDir],eax ; ... the current directory
- mov di,syslinux_cfg1
- push di
- call open
- pop di
- jnz .config_open
- mov di,syslinux_cfg2
- push di
- call open
- pop di
- jnz .config_open
- mov di,syslinux_cfg3
- push di
- call open
- pop di
- jz no_config_file
-.config_open:
- push si
- mov si,di
- push si
- mov di,CurrentDirName
- ; This is inefficient as it will copy more than needed
- ; but not by too much
- call strcpy
- mov ax,config_name ;Cut it down
- pop si
- sub ax,si
- mov di,CurrentDirName
- add di,ax
- mov byte [di],0
- pop si
- mov eax,[PrevDir] ; Make the directory with syslinux.cfg ...
- mov [CurrentDir],eax ; ... the current directory
-
-;
-; Now we have the config file open. Parse the config file and
-; run the user interface.
-;
-%include "ui.inc"
-
-;
-; allocate_file: Allocate a file structure
-;
-; If successful:
-; ZF set
-; BX = file pointer
-; In unsuccessful:
-; ZF clear
-;
-allocate_file:
- TRACER 'a'
- push cx
- mov bx,Files
- mov cx,MAX_OPEN
-.check: cmp dword [bx], byte 0
- je .found
- add bx,open_file_t_size ; ZF = 0
- loop .check
- ; ZF = 0 if we fell out of the loop
-.found: pop cx
- ret
-
-;
-; alloc_fill_dir:
-; Allocate then fill a file structure for a directory starting in
-; sector EAX.
-;
-; Assumes DS == ES == CS.
-;
-; If successful:
-; ZF clear
-; SI = file pointer
-; If unsuccessful
-; ZF set
-; EAX clobbered
-;
-alloc_fill_dir:
- push bx
- call allocate_file
- jnz .alloc_failure
-.found:
- mov si,bx
- mov [si+file_sector],eax ; Current sector
- mov dword [si+file_bytesleft],0 ; Current offset
- mov [si+file_left],eax ; Beginning sector
- pop bx
- ret
-
-.alloc_failure:
- pop bx
- xor eax,eax ; ZF <- 1
- ret
-
-;
-; search_dos_dir:
-; Search a specific directory for a pre-mangled filename in
-; MangledBuf, in the directory starting in sector EAX.
-;
-; NOTE: This file considers finding a zero-length file an
-; error. This is so we don't have to deal with that special
-; case elsewhere in the program (most loops have the test
-; at the end).
-;
-; Assumes DS == ES == CS.
-;
-; If successful:
-; ZF clear
-; SI = file pointer
-; EAX = file length (MAY BE ZERO!)
-; DL = file attribute
-; DH = clobbered
-; If unsuccessful
-; ZF set
-; EAX, SI, DX clobbered
-;
-
-search_dos_dir:
- push bx
- call allocate_file
- jnz .alloc_failure
-
- push cx
- push gs
- push es
- push ds
- pop es ; ES = DS
-
- ; Compute the value of a possible VFAT longname
- ; "last" entry (which, of course, comes first...)
- push ax
- push dx
- mov ax,[NameLen]
- add ax,12
- xor dx,dx
- mov cx,13
- div cx
- or al,40h
- mov [VFATInit],al
- mov [VFATNext],al
- pop dx
- pop ax
-
-.scansector:
- ; EAX <- directory sector to scan
- call getcachesector
- ; GS:SI now points to this sector
-
- mov cx,SECTOR_SIZE/32 ; 32 == directory entry size
-.scanentry:
- cmp byte [gs:si],0
- jz .failure ; Hit directory high water mark
- cmp word [gs:si+11],0Fh ; Long filename
- jne .short_entry
-
- ; Process a VFAT long entry
- pusha
- mov al,[gs:si]
- cmp al,[VFATNext]
- jne .not_us
- mov bl,[gs:si+13]
- test al,40h
- jz .match_csum
- ; Get the initial checksum value
- mov [VFATCsum],bl
- jmp .done_csum
-.match_csum:
- cmp bl,[VFATCsum]
- jne .not_us ; Checksum mismatch
-.done_csum:
- and ax,03fh
- jz .not_us ; Can't be zero...
- dec ax
- mov [VFATNext],al ; Optimistically...
- mov bx,ax
- shl bx,2 ; *4
- add ax,bx ; *5
- add bx,bx ; *8
- add bx,ax ; *13
- cmp bx,[NameLen]
- jae .not_us
- mov di,[NameStart]
- inc si
- mov cx,13
-.vfat_cmp:
- gs lodsw
- push bx
- cmp bx,[NameLen]
- jae .vfat_tail
- movzx bx,byte [bx+di]
- add bx,bx
- cmp ax,[cp_unicode+bx] ; Primary case
- je .ucs_ok
- cmp ax,[cp_unicode_alt+bx] ; Alternate case
- je .ucs_ok
- ; Mismatch...
- jmp .not_us_pop
-.vfat_tail:
- ; *AT* the end we should have 0x0000, *AFTER* the end
- ; we should have 0xFFFF...
- je .vfat_end
- inc ax ; 0xFFFF -> 0x0000
-.vfat_end:
- and ax,ax
- jnz .not_us_pop
-.ucs_ok:
- pop bx
- inc bx
- cmp cx,3
- je .vfat_adj_add2
- cmp cx,9
- jne .vfat_adj_add0
-.vfat_adj_add3: inc si
-.vfat_adj_add2: inc si
-.vfat_adj_add1: inc si
-.vfat_adj_add0:
- loop .vfat_cmp
- ; Okay, if we got here we had a match on this particular
- ; entry... live to see another one.
- popa
- jmp .next_entry
-
-.not_us_pop:
- pop bx
-.not_us:
- popa
- jmp .nomatch
-
-.short_entry:
- test byte [gs:si+11],8 ; Ignore volume labels
- jnz .nomatch
-
- cmp byte [VFATNext],0 ; Do we have a longname match?
- jne .no_long_match
-
- ; We already have a VFAT longname match, however,
- ; the match is only valid if the checksum matches
- push cx
- push si
- push ax
- xor ax,ax
- mov cx,11
-.csum_loop:
- gs lodsb
- ror ah,1
- add ah,al
- loop .csum_loop
- cmp ah,[VFATCsum]
- pop ax
- pop si
- pop cx
- je .found ; Got a match on longname
-
-.no_long_match: ; Look for a shortname match
- push cx
- push si
- push di
- mov di,MangledBuf
- mov cx,11
- gs repe cmpsb
- pop di
- pop si
- pop cx
- je .found
-.nomatch:
- ; Reset the VFAT matching state machine
- mov dh,[VFATInit]
- mov [VFATNext],dh
-.next_entry:
- add si,32
- dec cx
- jnz .scanentry
-
- call nextsector
- jnc .scansector ; CF is set if we're at end
-
- ; If we get here, we failed
-.failure:
- pop es
- pop gs
- pop cx
-.alloc_failure:
- pop bx
- xor eax,eax ; ZF <- 1
- ret
-.found:
- mov eax,[gs:si+28] ; File size
- add eax,SECTOR_SIZE-1
- shr eax,SECTOR_SHIFT
- mov [bx+4],eax ; Sector count
-
- mov cl,[ClustShift]
- mov dx,[gs:si+20] ; High cluster word
- shl edx,16
- mov dx,[gs:si+26] ; Low cluster word
- sub edx,2
- shl edx,cl
- add edx,[DataArea]
- mov [bx],edx ; Starting sector
-
- mov eax,[gs:si+28] ; File length again
- mov dl,[gs:si+11] ; File attribute
- mov si,bx ; File pointer...
- and si,si ; ZF <- 0
-
- pop es
- pop gs
- pop cx
- pop bx
- ret
-
- section .data16
- alignz 4
- ; Note: we have no use of the first 32 bytes (header),
- ; nor of the folloing 32 bytes (case mapping of control
- ; characters), as long as we adjust the offsets appropriately.
-codepage equ $-(32+32)
-codepage_data: incbin "codepage.cp",32+32
-cp_uppercase equ codepage+cp.uppercase
-cp_unicode equ codepage+cp.unicode
-cp_unicode_alt equ codepage+cp.unicode_alt
-codepage_end equ $
-
- section .text16
-;
-; Input: UCS-2 character in AX
-; Output: Single byte character in AL, ZF = 1
-; On failure, returns ZF = 0
-;
-ucs2_to_cp:
- push es
- push di
- push cx
- push cs
- pop es
- mov di,cp_unicode
- mov cx,512
- repne scasw
- xchg ax,cx
- pop cx
- pop di
- pop es
- not ax ; Doesn't change the flags!
- ret
-
- section .bss16
-VFATInit resb 1
-VFATNext resb 1
-VFATCsum resb 1
-
- section .text16
-;
-; close_file:
-; Deallocates a file structure (pointer in SI)
-; Assumes CS == DS.
-;
-close_file:
- and si,si
- jz .closed
- mov dword [si],0 ; First dword == file_sector
- xor si,si
-.closed: ret
-
-;
-; close_dir:
-; Deallocates a directory structure (pointer in SI)
-; Assumes CS == DS.
-;
-close_dir:
- and si,si
- jz .closed
- mov dword [si],0 ; First dword == file_sector
- xor si,si
-.closed: ret
-
-;
-; searchdir:
-;
-; Open a file
-;
-; On entry:
-; DS:DI = filename
-; If successful:
-; ZF clear
-; SI = file pointer
-; EAX = file length in bytes
-; If unsuccessful
-; ZF set
-;
-; Assumes CS == DS == ES, and trashes BX and CX.
-;
-searchdir:
- mov eax,[CurrentDir]
- cmp byte [di],'/' ; Root directory?
- jne .notroot
- mov eax,[RootDir]
- inc di
-.notroot:
-
-.pathwalk:
- push eax ; <A> Current directory sector
- mov si,di
-.findend:
- lodsb
- cmp al,' '
- jbe .endpath
- cmp al,'/'
- jne .findend
-.endpath:
- xchg si,di ; GRC: si begin; di end[ /]+1
- pop eax ; <A> Current directory sector
-
- ; GRC Here I need to check if di-1 = si which signifies
- ; we have the desired directory in EAX
- ; What about where the file name = "."; later
- mov dx,di
- dec dx
- cmp dx,si
- jz .founddir
-
- mov [PrevDir],eax ; Remember last directory searched
-
- push di
- call mangle_dos_name ; MangledBuf <- component
- call search_dos_dir
- pop di
- jz .notfound ; Pathname component missing
-
- cmp byte [di-1],'/' ; Do we expect a directory
- je .isdir
-
- ; Otherwise, it should be a file
-.isfile:
- test dl,18h ; Subdirectory|Volume Label
- jnz .badfile ; If not a file, it's a bad thing
-
- ; SI and EAX are already set
- mov [si+file_bytesleft],eax
- push eax
- add eax,SECTOR_SIZE-1
- shr eax,SECTOR_SHIFT
- mov [si+file_left],eax ; Sectors left
- pop eax
- and eax,eax ; EAX != 0
- jz .badfile
- ret ; Done!
-
- ; If we expected a directory, it better be one...
-.isdir:
- test dl,10h ; Subdirectory
- jz .badfile
-
- xor eax,eax
- xchg eax,[si+file_sector] ; Get sector number and free file structure
- jmp .pathwalk ; Walk the next bit of the path
-
- ; Found the desired directory; ZF set but EAX not 0
-.founddir:
- ret
-
-.badfile:
- xor eax,eax
- mov [si],eax ; Free file structure
-
-.notfound:
- xor eax,eax ; Zero out EAX
- ret
-
-;
-; readdir: Read one file from a directory
-;
-; ES:DI -> String buffer (filename)
-; DS:SI -> Pointer to open_file_t
-; DS Must be the SYSLINUX Data Segment
-;
-; Returns the file's name in the filename string buffer
-; EAX returns the file size
-; EBX returns the beginning sector (currently without offsetting)
-; DL returns the file type
-; The directory handle's data is incremented to reflect a name read.
-;
-readdir:
- push ecx
- push bp ; Using bp to transfer between segment registers
- push si
- push es
- push fs ; Using fs to store the current es (from COMBOOT)
- push gs
- mov bp,es
- mov fs,bp
- cmp si,0
- jz .fail
-.load_handle:
- mov eax,[ds:si+file_sector] ; Current sector
- mov ebx,[ds:si+file_bytesleft] ; Current offset
- cmp eax,0
- jz .fail
-.fetch_cache:
- call getcachesector
-.move_current:
- add si,bx ; Resume last position in sector
- mov ecx,SECTOR_SIZE ; 0 out high part
- sub cx,bx
- shr cx,5 ; Number of entries left
-.scanentry:
- cmp byte [gs:si],0
- jz .fail
- cmp word [gs:si+11],0Fh ; Long filename
- jne .short_entry
-
-.vfat_entry:
- push eax
- push ecx
- push si
- push di
-.vfat_ln_info: ; Get info about the line that we're on
- mov al,[gs:si]
- test al,40h
- jz .vfat_tail_ln
- and al,03Fh
- mov ah,1 ; On beginning line
- jmp .vfat_ck_ln
-
-.vfat_tail_ln: ; VFAT tail line processing (later in VFAT, head in name)
- test al,80h ; Invalid data?
- jnz .vfat_abort
- mov ah,0 ; Not on beginning line
- cmp dl,al
- jne .vfat_abort ; Is this the entry we need?
- mov bl,[gs:si+13]
- cmp bl,[VFATCsum]
- je .vfat_cp_ln
- jmp .vfat_abort
-
-.vfat_ck_ln: ; Load this line's VFAT CheckSum
- mov bl,[gs:si+13]
- mov [VFATCsum],bl
-.vfat_cp_ln: ; Copy VFAT line
- dec al ; Store the next line we need
- mov dx,ax ; Use DX to store the progress
- mov cx,13 ; 13 characters per VFAT DIRENT
- cbw ; AH <- 0
- mul cl ; Offset for DI
- add di,ax ; Increment DI
- inc si ; Align to the real characters
-.vfat_cp_chr:
- gs lodsw ; Unicode here!!
- call ucs2_to_cp ; Convert to local codepage
- jnz .vfat_abort ; Use short name if character not on codepage
- stosb ; CAN NOT OVERRIDE es
- cmp al,0
- jz .vfat_find_next ; Null-terminated string; don't process more
- cmp cx,3
- je .vfat_adj_add2
- cmp cx,9
- jne .vfat_adj_add0
-.vfat_adj_add3: inc si
-.vfat_adj_add2: inc si
-.vfat_adj_add1: inc si
-.vfat_adj_add0:
- loop .vfat_cp_chr
- cmp dh,1 ; Is this the first round?
- jnz .vfat_find_next
-.vfat_null_term: ; Need to null-terminate if first line as we rolled over the end
- mov al,0
- stosb
-
-.vfat_find_next: ;Find the next part of the name
- pop di
- pop si
- pop ecx
- pop eax
- cmp dl,0
- jz .vfat_find_info ; We're done with the name
- add si,DIRENT_SIZE
- dec cx
- jnz .vfat_entry
- call nextsector
- jnc .vfat_entry ; CF is set if we're at end
- jmp .fail
-.vfat_find_info: ; Fetch next entry for the size/"INode"
- add si,DIRENT_SIZE
- dec cx
- jnz .get_info
- call nextsector
- jnc .get_info ; CF is set if we're at end
- jmp .fail
-.vfat_abort: ; Something went wrong, skip
- pop di
- pop si
- pop ecx
- pop eax
- jmp .skip_entry
-
-.short_entry:
- test byte [gs:si+11],8 ; Ignore volume labels //HERE
- jnz .skip_entry
- mov edx,eax ;Save current sector
- push cx
- push si
- push di
- mov cx,8
-.short_file:
- gs lodsb
- cmp al,'.'
- jz .short_dot
-.short_file_loop:
- cmp al,' '
- jz .short_skip_bs
- stosb
- loop .short_file_loop
- jmp .short_period
-.short_skip_bs: ; skip blank spaces in FILENAME (before EXT)
- add si,cx
- dec si
-.short_period:
- mov al,'.'
- stosb
- mov cx,3
-.short_ext:
- gs lodsb
- cmp al,' '
- jz .short_done
- stosb
- loop .short_ext
- jmp .short_done
-.short_dot:
- stosb
- gs lodsb
- cmp al,' '
- jz .short_done
- stosb
-.short_done:
- mov al,0 ; Null-terminate the short strings
- stosb
- pop di
- pop si
- pop cx
- mov eax,edx
-.get_info:
- mov ebx,[gs:si+28] ; length
- mov dl,[gs:si+11] ; type
-.next_entry:
- add si,DIRENT_SIZE
- dec cx
- jnz .store_offset
- call nextsector
- jnc .store_sect ; CF is set if we're at end
- jmp .fail
-
-.skip_entry:
- add si,DIRENT_SIZE
- dec cx
- jnz .scanentry
- call nextsector
- jnc .scanentry ; CF is set if we're at end
- jmp .fail
-
-.store_sect:
- pop gs
- pop fs
- pop es
- pop si
- mov [ds:si+file_sector],eax
- mov eax,0 ; Now at beginning of new sector
- jmp .success
-
-.store_offset:
- pop gs
- pop fs
- pop es
- pop si ; cx=num remain; SECTOR_SIZE-(cx*32)=cur pos
- shl ecx,DIRENT_SHIFT
- mov eax,SECTOR_SIZE
- sub eax,ecx
- and eax,0ffffh
-
-.success:
- mov [ds:si+file_bytesleft],eax
- ; "INode" number = ((CurSector-RootSector)*SECTOR_SIZE + Offset)/DIRENT_SIZE)
- mov ecx,eax
- mov eax,[ds:si+file_sector]
- sub eax,[RootDir]
- shl eax,SECTOR_SHIFT
- add eax,ecx
- shr eax,DIRENT_SHIFT
- dec eax
- xchg eax,ebx ; -> EBX=INode, EAX=FileSize
- jmp .done
-
-.fail:
- pop gs
- pop fs
- pop es
- pop si
- call close_dir
- xor eax,eax
- stc
-.done:
- pop bp
- pop ecx
-.end:
- ret
-
- section .bss16
- alignb 4
-PrevDir resd 1 ; Last scanned directory
-
- section .text16
-
-;
-;
-; kaboom2: once everything is loaded, replace the part of kaboom
-; starting with "kaboom.patch" with this part
-
-kaboom2:
- mov si,err_bootfailed
- call writestr
- cmp byte [kaboom.again+1],18h ; INT 18h version?
- je .int18
- call getchar
- call vgaclearmode
- int 19h ; And try once more to boot...
-.norge: jmp short .norge ; If int 19h returned; this is the end
-.int18:
- call vgaclearmode
- int 18h
-.noreg: jmp short .noreg ; Nynorsk
-
-;
-; mangle_name: Mangle a filename pointed to by DS:SI into a buffer pointed
-; to by ES:DI; ends on encountering any whitespace.
-; DI is preserved.
-;
-; This verifies that a filename is < FILENAME_MAX characters,
-; doesn't contain whitespace, zero-pads the output buffer,
-; and removes trailing dots and redundant slashes, plus changes
-; backslashes to forward slashes,
-; so "repe cmpsb" can do a compare, and the path-searching routine
-; gets a bit of an easier job.
-;
-;
-mangle_name:
- push di
- push bx
- xor ax,ax
- mov cx,FILENAME_MAX-1
- mov bx,di
-
-.mn_loop:
- lodsb
- cmp al,' ' ; If control or space, end
- jna .mn_end
- cmp al,'\' ; Backslash?
- jne .mn_not_bs
- mov al,'/' ; Change to forward slash
-.mn_not_bs:
- cmp al,ah ; Repeated slash?
- je .mn_skip
- xor ah,ah
- cmp al,'/'
- jne .mn_ok
- mov ah,al
-.mn_ok stosb
-.mn_skip: loop .mn_loop
-.mn_end:
- cmp bx,di ; At the beginning of the buffer?
- jbe .mn_zero
- cmp byte [es:di-1],'.' ; Terminal dot?
- je .mn_kill
- cmp byte [es:di-1],'/' ; Terminal slash?
- jne .mn_zero
-.mn_kill: dec di ; If so, remove it
- inc cx
- jmp short .mn_end
-.mn_zero:
- inc cx ; At least one null byte
- xor ax,ax ; Zero-fill name
- rep stosb
- pop bx
- pop di
- ret ; Done
-
-;
-; unmangle_name: Does the opposite of mangle_name; converts a DOS-mangled
-; filename to the conventional representation. This is needed
-; for the BOOT_IMAGE= parameter for the kernel.
-; NOTE: A 13-byte buffer is mandatory, even if the string is
-; known to be shorter.
-;
-; DS:SI -> input mangled file name
-; ES:DI -> output buffer
-;
-; On return, DI points to the first byte after the output name,
-; which is set to a null byte.
-;
-unmangle_name: call strcpy
- dec di ; Point to final null byte
- ret
-
-;
-; mangle_dos_name:
-; Mangle a DOS filename component pointed to by DS:SI
-; into [MangledBuf]; ends on encountering any whitespace or
-; slash.
-;
-; WARNING: saves pointers into the buffer for longname
-; matches!
-;
-; Assumes CS == DS == ES.
-;
-
-mangle_dos_name:
- pusha
- mov di,MangledBuf
- mov [NameStart],si
-
- mov cx,11 ; # of bytes to write
- mov bx,cp_uppercase ; Case-conversion table
-.loop:
- lodsb
- cmp al,' ' ; If control or space, end
- jna .end
- cmp al,'/' ; Slash, too
- je .end
- cmp al,'.' ; Period -> space-fill
- je .is_period
- xlatb ; Convert to upper case
- mov ah,cl ; If the first byte (only!)...
- cmp ax,0BE5h ; ... equals E5 hex ...
- jne .charok
- mov al,05h ; ... change it to 05 hex
-.charok: stosb
- loop .loop ; Don't continue if too long
- ; Find the end for the benefit of longname search
-.find_end:
- lodsb
- cmp al,' '
- jna .end
- cmp al,'/'
- jne .find_end
-.end:
- dec si
- sub si,[NameStart]
- mov [NameLen],si
- mov al,' ' ; Space-fill name
- rep stosb ; Doesn't do anything if CX=0
- popa
- ret ; Done
-
-.is_period:
- mov al,' ' ; We need to space-fill
-.period_loop: cmp cx,3 ; If <= 3 characters left
- jbe .loop ; Just ignore it
- stosb ; Otherwise, write a space
- loop .period_loop ; Dec CX and *always* jump
-
- section .bss16
- alignb 2
-NameStart resw 1
-NameLen resw 1
-MangledBuf resb 11
-
- section .text16
-;
-; getfssec_edx: Get multiple sectors from a file
-;
-; This routine makes sure the subtransfers do not cross a 64K boundary,
-; and will correct the situation if it does, UNLESS *sectors* cross
-; 64K boundaries.
-;
-; ES:BX -> Buffer
-; EDX -> Current sector number
-; CX -> Sector count (0FFFFh = until end of file)
-; Must not exceed the ES segment
-; Returns EDX=0, CF=1 on EOF (not necessarily error)
-; All arguments are advanced to reflect data read.
-;
-getfssec_edx:
- push ebp
- push eax
-.getfragment:
- xor ebp,ebp ; Fragment sector count
- push edx ; Starting sector pointer
-.getseccnt:
- inc bp
- dec cx
- jz .do_read
- xor eax,eax
- mov ax,es
- shl ax,4
- add ax,bx ; Now AX = how far into 64K block we are
- not ax ; Bytes left in 64K block
- inc eax
- shr eax,SECTOR_SHIFT ; Sectors left in 64K block
- cmp bp,ax
- jnb .do_read ; Unless there is at least 1 more sector room...
- mov eax,edx ; Current sector
- inc edx ; Predict it's the linearly next sector
- call nextsector
- jc .do_read
- cmp edx,eax ; Did it match?
- jz .getseccnt
-.do_read:
- pop eax ; Starting sector pointer
- call getlinsecsr
- lea eax,[eax+ebp-1] ; This is the last sector actually read
- shl bp,9
- add bx,bp ; Adjust buffer pointer
- call nextsector
- jc .eof
- mov edx,eax
- and cx,cx
- jnz .getfragment
-.done:
- pop eax
- pop ebp
- ret
-.eof:
- xor edx,edx
- stc
- jmp .done
-
-;
-; getfssec: Get multiple sectors from a file
-;
-; Same as above, except SI is a pointer to a open_file_t
-;
-; ES:BX -> Buffer
-; DS:SI -> Pointer to open_file_t
-; CX -> Sector count (0FFFFh = until end of file)
-; Must not exceed the ES segment
-; Returns CF=1 on EOF (not necessarily error)
-; ECX returns number of bytes read.
-; All arguments are advanced to reflect data read.
-;
-getfssec:
- push edx
- movzx edx,cx
- push edx ; Zero-extended CX
- cmp edx,[si+file_left]
- jbe .sizeok
- mov edx,[si+file_left]
- mov cx,dx
-.sizeok:
- sub [si+file_left],edx
- mov edx,[si+file_sector]
- call getfssec_edx
- mov [si+file_sector],edx
- pop ecx ; Sectors requested read
- shl ecx,SECTOR_SHIFT
- cmp ecx,[si+file_bytesleft]
- ja .eof
-.noteof:
- sub [si+file_bytesleft],ecx ; CF <- 0
- pop edx
- ret
-.eof:
- mov ecx,[si+file_bytesleft]
- call close_file
- pop edx
- stc
- ret
-
-;
-; nextcluster: Advance a cluster pointer in EDI to the next cluster
-; pointed at in the FAT tables. CF=0 on return if end of file.
-;
-nextcluster:
- jmp strict short nextcluster_fat28 ; This gets patched
-
-nextcluster_fat12:
- push eax
- push edx
- push bx
- push cx
- push si
- mov edx,edi
- shr edi,1
- pushf ; Save the shifted-out LSB (=CF)
- add edx,edi
- mov eax,edx
- shr eax,9
- call getfatsector
- mov bx,dx
- and bx,1FFh
- mov cl,[gs:si+bx]
- inc edx
- mov eax,edx
- shr eax,9
- call getfatsector
- mov bx,dx
- and bx,1FFh
- mov ch,[gs:si+bx]
- popf
- jnc .even
- shr cx,4
-.even: and cx,0FFFh
- movzx edi,cx
- cmp di,0FF0h
- pop si
- pop cx
- pop bx
- pop edx
- pop eax
- ret
-
-;
-; FAT16 decoding routine.
-;
-nextcluster_fat16:
- push eax
- push si
- push bx
- mov eax,edi
- shr eax,SECTOR_SHIFT-1
- call getfatsector
- mov bx,di
- add bx,bx
- and bx,1FEh
- movzx edi,word [gs:si+bx]
- cmp di,0FFF0h
- pop bx
- pop si
- pop eax
- ret
-;
-; FAT28 ("FAT32") decoding routine.
-;
-nextcluster_fat28:
- push eax
- push si
- push bx
- mov eax,edi
- shr eax,SECTOR_SHIFT-2
- call getfatsector
- mov bx,di
- add bx,bx
- add bx,bx
- and bx,1FCh
- mov edi,dword [gs:si+bx]
- and edi,0FFFFFFFh ; 28 bits only
- cmp edi,0FFFFFF0h
- pop bx
- pop si
- pop eax
- ret
-
-;
-; nextsector: Given a sector in EAX on input, return the next sector
-; of the same filesystem object, which may be the root
-; directory or a cluster chain. Returns EOF.
-;
-; Assumes CS == DS.
-;
-nextsector:
- push edi
- push edx
- mov edx,[DataArea]
- mov edi,eax
- sub edi,edx
- jae .isdata
-
- ; Root directory
- inc eax
- cmp eax,edx
- cmc
- jmp .done
-
-.isdata:
- not edi
- test edi,[ClustMask]
- jz .endcluster
-
- ; It's not the final sector in a cluster
- inc eax
- jmp .done
-
-.endcluster:
- push gs ; nextcluster trashes gs
- push cx
- not edi
- mov cl,[ClustShift]
- shr edi,cl
- add edi,2
-
- ; Now EDI contains the cluster number
- call nextcluster
- cmc
- jc .exit ; There isn't anything else...
-
- ; New cluster number now in EDI
- sub edi,2
- shl edi,cl ; CF <- 0, unless something is very wrong
- lea eax,[edi+edx]
-.exit:
- pop cx
- pop gs
-.done:
- pop edx
- pop edi
- ret
-
-;
-; getfatsector: Check for a particular sector (in EAX) in the FAT cache,
-; and return a pointer in GS:SI, loading it if needed.
-;
-; Assumes CS == DS.
-;
-getfatsector:
- add eax,[FAT] ; FAT starting address
- jmp getcachesector
-
-; -----------------------------------------------------------------------------
-; Common modules
-; -----------------------------------------------------------------------------
-
-%include "common.inc" ; Universal modules
-%include "plaincon.inc" ; writechr
-%include "writestr.inc" ; String output
-%include "writehex.inc" ; Hexadecimal output
-%include "cache.inc" ; Metadata disk cache
-%include "localboot.inc" ; Disk-based local boot
-
-; -----------------------------------------------------------------------------
-; Begin data section
-; -----------------------------------------------------------------------------
-
- section .data16
-copyright_str db ' Copyright (C) 1994-'
- asciidec YEAR
- db ' H. Peter Anvin et al', CR, LF, 0
-err_bootfailed db CR, LF, 'Boot failed: please change disks and press '
- db 'a key to continue.', CR, LF, 0
-syslinux_cfg1 db '/boot' ; /boot/syslinux/syslinux.cfg
-syslinux_cfg2 db '/syslinux' ; /syslinux/syslinux.cfg
-syslinux_cfg3 db '/' ; /syslinux.cfg
-config_name db 'syslinux.cfg', 0 ; syslinux.cfg
-
-;
-; Config file keyword table
-;
-%include "keywords.inc"
-
-;
-; Extensions to search for (in *forward* order).
-;
-exten_table: db '.cbt' ; COMBOOT (specific)
- db '.bss' ; Boot Sector (add superblock)
- db '.bs', 0 ; Boot Sector
- db '.com' ; COMBOOT (same as DOS)
- db '.c32' ; COM32
-exten_table_end:
- dd 0, 0 ; Need 8 null bytes here
-
-;
-; Misc initialized (data) variables
-;
-%ifdef debug ; This code for debugging only
-debug_magic dw 0D00Dh ; Debug code sentinel
-%endif
+ section .rodata
alignz 4
-BufSafe dw trackbufsize/SECTOR_SIZE ; Clusters we can load into trackbuf
-BufSafeBytes dw trackbufsize ; = how many bytes?
-%ifndef DEPEND
-%if ( trackbufsize % SECTOR_SIZE ) != 0
-%error trackbufsize must be a multiple of SECTOR_SIZE
-%endif
-%endif
+ROOT_FS_OPS:
+ extern vfat_fs_ops
+ dd vfat_fs_ops
+ extern ext2_fs_ops
+ dd ext2_fs_ops
+ extern btrfs_fs_ops
+ dd btrfs_fs_ops
+ dd 0
+
+%include "diskfs.inc"
projects / profile / ivi / syslinux.git / blobdiff