; -*- fundamental -*- (asm-mode sucks)
-; $Id$
; ****************************************************************************
;
; ldlinux.asm
; from MS-LOSS, and can be especially useful in conjunction with the
; umsdos filesystem.
;
-; This file is loaded in stages; first the boot sector at offset 7C00h,
-; then the first sector (cluster, really, but we can only assume 1 sector)
-; of LDLINUX.SYS at 7E00h and finally the remainder of LDLINUX.SYS at 8000h.
-;
-; Copyright (C) 1994-2004 H. Peter Anvin
+; Copyright (C) 1994-2007 H. Peter Anvin
;
; This program is free software; you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation, Inc., 53 Temple Place Ste 330,
; Boston MA 02111-1307, USA; either version 2 of the License, or
; (at your option) any later version; incorporated herein by reference.
-;
+;
; ****************************************************************************
%ifndef IS_MDSLINUX
%define IS_SYSLINUX 1
%endif
-%include "macros.inc"
-%include "config.inc"
-%include "kernel.inc"
-%include "bios.inc"
-%include "tracers.inc"
+%include "head.inc"
;
; Some semi-configurable constants... change on your own risk.
;
my_id equ syslinux_id
-FILENAME_MAX_LG2 equ 4 ; log2(Max filename size Including final null)
-FILENAME_MAX equ 11 ; Max mangled filename size
-NULLFILE equ ' ' ; First char space == null filename
-retry_count equ 6 ; How patient are we with the disk?
+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
; Since there is no room in the bottom 64K for all of these, we
; stick them at vk_seg:0000 and copy them down before we need them.
;
-; Note: this structure can be added to, but it must
-;
-%define vk_power 7 ; log2(max number of vkernels)
-%define max_vk (1 << vk_power) ; Maximum number of vkernels
-%define vk_shift (16-vk_power) ; Number of bits to shift
-%define vk_size (1 << vk_shift) ; Size of a vkernel buffer
-
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
-%ifndef DEPEND
-%if (vk_end > vk_size) || (vk_size*max_vk > 65536)
-%error "Too many vkernels defined, reduce vk_power"
-%endif
-%endif
-
;
; Segment assignments in the bottom 640K
; Stick to the low 512K in case we're using something like M-systems flash
;
; Memory below this point is reserved for the BIOS and the MBR
;
- absolute 1000h
+ section .earlybss
trackbufsize equ 8192
trackbuf resb trackbufsize ; Track buffer goes here
getcbuf resb trackbufsize
-; ends at 5000h
-
-
-;
-; Constants for the xfer_buf_seg
-;
-; The xfer_buf_seg is also used to store message file buffers. We
-; need two trackbuffers (text and graphics), plus a work buffer
-; for the graphics decompressor.
-;
-xbs_textbuf equ 0 ; Also hard-coded, do not change
-xbs_vgabuf equ trackbufsize
-xbs_vgatmpbuf equ 2*trackbufsize
+ ; ends at 4800h
-
- absolute 5000h ; Here we keep our BSS stuff
-VKernelBuf: resb vk_size ; "Current" vkernel
- alignb 4
-AppendBuf resb max_cmd_len+1 ; append=
-Ontimeout resb max_cmd_len+1 ; ontimeout
-Onerror resb max_cmd_len+1 ; onerror
-KbdMap resb 256 ; Keyboard map
-FKeyName resb 10*16 ; File names for F-key help
-NumBuf resb 15 ; Buffer to load number
-NumBufEnd resb 1 ; Last byte in NumBuf
+ section .bss
alignb 8
; Expanded superblock
SuperInfo equ $
resq 16 ; The first 16 bytes expanded 8 times
-
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
-EndSector resd 1 ; Location of filesystem end
-
- alignb 4
-E820Buf resd 5 ; INT 15:E820 data buffer
-E820Mem resd 1 ; Memory detected by E820
-E820Max resd 1 ; Is E820 memory capped?
-HiLoadAddr resd 1 ; Address pointer for high load loop
-HighMemSize resd 1 ; End of memory pointer (bytes)
-RamdiskMax resd 1 ; Highest address for a ramdisk
-KernelSize resd 1 ; Size of kernel (bytes)
-SavedSSSP resd 1 ; Our SS:SP while running a COMBOOT image
-PMESP resd 1 ; Protected-mode ESP
-FSectors resd 1 ; Number of sectors in getc file
ClustSize resd 1 ; Bytes/cluster
ClustMask resd 1 ; Sectors/cluster - 1
-KernelName resb 12 ; Mangled name for kernel
- ; (note the spare byte after!)
-OrigKernelExt resd 1 ; Original kernel extension
-FBytes equ $ ; Used by open/getc
-FBytes1 resw 1
-FBytes2 resw 1
-DirBlocksLeft resw 1 ; Ditto
-RunLinClust resw 1 ; Cluster # for LDLINUX.SYS
-KernelSects resw 1 ; Kernel size in clusters
-FNextClust resw 1 ; Pointer to next cluster in d:o
-FPtr resw 1 ; Pointer to next char in buffer
-CmdOptPtr resw 1 ; Pointer to first option on cmd line
-KernelCNameLen resw 1 ; Length of unmangled kernel name
-InitRDCNameLen resw 1 ; Length of unmangled initrd name
-NextCharJump resw 1 ; Routine to interpret next print char
-SetupSecs resw 1 ; Number of setup sectors
-A20Test resw 1 ; Counter for testing status of A20
-A20Type resw 1 ; A20 type
-CmdLineLen resw 1 ; Length of command line including null
-GraphXSize resw 1 ; Width of splash screen file
-VGAPos resw 1 ; Pointer into VGA memory
-VGACluster resw 1 ; Cluster pointer for VGA image file
-VGAFilePtr resw 1 ; Pointer into VGAFileBuf
-Com32SysSP resw 1 ; SP saved during COM32 syscall
-DirScanCtr resw 1 ; OBSOLETE FIX THIS
-EndofDirSec resw 1 ; OBSOLETE FIX THIS
-CachePtrs times (65536/SECTOR_SIZE) resw 1
-NextCacheSlot resw 1
-CursorDX equ $
-CursorCol resb 1 ; Cursor column for message file
-CursorRow resb 1 ; Cursor row for message file
-ScreenSize equ $
-VidCols resb 1 ; Columns on screen-1
-VidRows resb 1 ; Rows on screen-1
-BaudDivisor resw 1 ; Baud rate divisor
-FlowControl equ $
-FlowOutput resb 1 ; Outputs to assert for serial flow
-FlowInput resb 1 ; Input bits for serial flow
-FlowIgnore resb 1 ; Ignore input unless these bits set
-TextAttribute resb 1 ; Text attribute for message file
-RetryCount resb 1 ; Used for disk access retries
-KbdFlags resb 1 ; Check for keyboard escapes
-LoadFlags resb 1 ; Loadflags from kernel
-A20Tries resb 1 ; Times until giving up on A20
-FuncFlag resb 1 ; Escape sequences received from keyboard
-DisplayMask resb 1 ; Display modes mask
CopySuper resb 1 ; Distinguish .bs versus .bss
DriveNumber resb 1 ; BIOS drive number
ClustShift resb 1 ; Shift count for sectors/cluster
ClustByteShift resb 1 ; Shift count for bytes/cluster
-MNameBuf resb 11 ; Generic mangled file name buffer
-InitRD resb 11 ; initrd= mangled name
-KernelCName resb 13 ; Unmangled kernel name
-InitRDCName resb 13 ; Unmangled initrd name
-TextColorReg resb 17 ; VGA color registers for text mode
-VGAFileBuf resb 13 ; Unmangled VGA image name
-VGAFileBufEnd equ $
-VGAFileMBuf resb 11 ; Mangled VGA image name
- alignb 4 ; For the good of REP MOVSD
-command_line resb max_cmd_len+2 ; Command line buffer
- alignb 4
-default_cmd resb max_cmd_len+1 ; "default" command line
alignb open_file_t_size
Files resb MAX_OPEN*open_file_t_size
+;
+; Constants for the xfer_buf_seg
+;
+; The xfer_buf_seg is also used to store message file buffers. We
+; need two trackbuffers (text and graphics), plus a work buffer
+; for the graphics decompressor.
+;
+xbs_textbuf equ 0 ; Also hard-coded, do not change
+xbs_vgabuf equ trackbufsize
+xbs_vgatmpbuf equ 2*trackbufsize
+
+
section .text
- org 7C00h
;
; Some of the things that have to be saved very early are saved
; "close" to the initial stack pointer offset, in order to
StackBuf equ $-44-32 ; Start the stack here (grow down - 4K)
PartInfo equ StackBuf ; Saved partition table entry
FloppyTable equ PartInfo+16 ; Floppy info table (must follow PartInfo)
-OrigFDCTabPtr equ StackBuf-4 ; The high dword on the stack
+OrigFDCTabPtr equ StackBuf-8 ; The 2nd high dword on the stack
+OrigESDI equ StackBuf-4 ; The high dword on the stack
;
; Primary entry point. Tempting as though it may be, we can't put the
; Note we don't check the constraints above now; we did that at install
; time (we hope!)
;
-
-;floppy_table equ $ ; No sense in wasting memory, overwrite start
-
start:
cli ; No interrupts yet, please
cld ; Copy upwards
xor ax,ax
mov ss,ax
mov sp,StackBuf ; Just below BSS
+ push es ; Save initial ES:DI -> $PnP pointer
+ push di
mov es,ax
;
; DS:SI may contain a partition table entry. Preserve it for us.
;
mov cx,8 ; Save partition info
- mov di,sp
+ mov di,PartInfo
rep movsw
mov ds,ax ; Now we can initialize DS...
;
sti
-
;
; Do we have EBIOS (EDD)?
;
;
; We have EDD support...
;
- mov byte [getlinsec+1],getlinsec_ebios-(getlinsec+2)
+ mov byte [getlinsec.jmp+1],(getlinsec_ebios-(getlinsec.jmp+2))
.noedd:
;
mov eax,[FirstSector] ; Sector start
mov bx,ldlinux_sys ; Where to load it
call getonesec
-
+
; Some modicum of integrity checking
- cmp dword [ldlinux_magic],LDLINUX_MAGIC
- jne kaboom
- cmp dword [ldlinux_magic+4],HEXDATE
+ cmp dword [ldlinux_magic+4],LDLINUX_MAGIC^HEXDATE
jne kaboom
; Go for it...
jmp ldlinux_ent
;
-; kaboom: write a message and bail out.
-;
-kaboom:
- xor si,si
- mov ss,si
- mov sp,StackBuf-4 ; Reset stack
- mov ds,si ; Reset data segment
- pop dword [fdctab] ; Restore FDC table
-.patch: mov si,bailmsg
- call writestr ; Returns with AL = 0
- cbw ; AH <- 0
- int 16h ; Wait for keypress
- int 19h ; And try once more to boot...
-.norge: jmp short .norge ; If int 19h returned; this is the end
-
-;
-;
-; writestr: write a null-terminated string to the console
-; This assumes we're on page 0. This is only used for early
-; messages, so it should be OK.
-;
-writestr:
-.loop: lodsb
- and al,al
- jz .return
- mov ah,0Eh ; Write to screen as TTY
- mov bx,0007h ; Attribute
- int 10h
- jmp short .loop
-.return: ret
-
-;
-; xint13: wrapper for int 13h which will retry 6 times and then die,
-; AND save all registers except BP
-;
-xint13:
-.again:
- mov bp,retry_count
-.loop: pushad
- int 13h
- popad
- jnc writestr.return
- dec bp
- jnz .loop
-.disk_error:
- jmp strict near kaboom ; Patched
-
-
-;
; getonesec: get one disk sector
;
getonesec:
; the order to dst,src to keep things sane.
;
getlinsec:
- jmp strict short getlinsec_cbios ; This is patched
+ add eax,[bsHidden] ; Add partition offset
+ xor edx,edx ; Zero-extend LBA (eventually allow 64 bits)
+
+.jmp: jmp strict short getlinsec_cbios
;
; getlinsec_ebios:
; getlinsec implementation for EBIOS (EDD)
;
getlinsec_ebios:
- mov si,dapa ; Load up the DAPA
- mov [si+4],bx
- mov [si+6],es
- mov [si+8],eax
.loop:
push bp ; Sectors left
+.retry2:
call maxtrans ; Enforce maximum transfer size
-.bp_ok:
- mov [si+2],bp
+ movzx edi,bp ; Sectors we are about to read
+ mov cx,retry_count
+.retry:
+
+ ; Form DAPA on stack
+ push edx
+ push eax
+ push es
+ push bx
+ push di
+ push word 16
+ mov si,sp
+ pushad
mov dl,[DriveNumber]
+ push ds
+ push ss
+ pop ds ; DS <- SS
mov ah,42h ; Extended Read
- call xint13
- pop bp
- movzx eax,word [si+2] ; Sectors we read
- add [si+8],eax ; Advance sector pointer
- sub bp,ax ; Sectors left
- shl ax,9 ; 512-byte sectors
- add [si+4],ax ; Advance buffer pointer
+ int 13h
+ pop ds
+ popad
+ lea sp,[si+16] ; Remove DAPA
+ jc .error
+ pop bp
+ add eax,edi ; Advance sector pointer
+ sub bp,di ; Sectors left
+ shl di,SECTOR_SHIFT ; 512-byte sectors
+ add bx,di ; Advance buffer pointer
and bp,bp
jnz .loop
- mov eax,[si+8] ; Next sector
- mov bx,[si+4] ; Buffer pointer
+
ret
+.error:
+ ; Some systems seem to get "stuck" in an error state when
+ ; using EBIOS. Doesn't happen when using CBIOS, which is
+ ; good, since some other systems get timeout failures
+ ; waiting for the floppy disk to spin up.
+
+ pushad ; Try resetting the device
+ xor ax,ax
+ mov dl,[DriveNumber]
+ int 13h
+ popad
+ loop .retry ; CX-- and jump if not zero
+
+ ;shr word [MaxTransfer],1 ; Reduce the transfer size
+ ;jnz .retry2
+
+ ; Total failure. Try falling back to CBIOS.
+ mov byte [getlinsec.jmp+1],(getlinsec_cbios-(getlinsec.jmp+2))
+ ;mov byte [MaxTransfer],63 ; Max possibe CBIOS transfer
+
+ pop bp
+ ; ... fall through ...
+
;
; getlinsec_cbios:
;
;
getlinsec_cbios:
.loop:
+ push edx
push eax
push bp
push bx
; Dividing by sectors to get (track,sector): we may have
; up to 2^18 tracks, so we need to use 32-bit arithmetric.
;
- xor edx,edx ; Zero-extend LBA to 64 bits
div esi
xor cx,cx
xchg cx,dx ; CX <- sector index (0-based)
; EDX <- 0
; eax = track #
div edi ; Convert track to head/cyl
+
+ ; We should test this, but it doesn't fit...
+ ; cmp eax,1023
+ ; ja .error
+
;
; Now we have AX = cyl, DX = head, CX = sector (0-based),
; BP = sectors to transfer, SI = bsSecPerTrack,
cmp bp,si
jna .bp_ok
mov bp,si
-.bp_ok:
+.bp_ok:
shl ah,6 ; Because IBM was STOOPID
; and thought 8 bits were enough
mov dl,[DriveNumber]
xchg ax,bp ; Sector to transfer count
mov ah,02h ; Read sectors
- call xint13
- movzx ecx,al
- shl ax,9 ; Convert sectors in AL to bytes in AX
+ mov bp,retry_count
+.retry:
+ pushad
+ int 13h
+ popad
+ jc .error
+.resume:
+ movzx ecx,al ; ECX <- sectors transferred
+ shl ax,SECTOR_SHIFT ; Convert sectors in AL to bytes in AX
pop bx
add bx,ax
pop bp
pop eax
+ pop edx
add eax,ecx
sub bp,cx
jnz .loop
ret
+.error:
+ dec bp
+ jnz .retry
+
+ xchg ax,bp ; Sectors transferred <- 0
+ shr word [MaxTransfer],1
+ jnz .resume
+ ; Fall through to disk_error
+
+;
+; kaboom: write a message and bail out.
+;
+disk_error:
+kaboom:
+ xor si,si
+ mov ss,si
+ mov sp,StackBuf-4 ; Reset stack
+ mov ds,si ; Reset data segment
+ pop dword [fdctab] ; Restore FDC table
+.patch: ; When we have full code, intercept here
+ mov si,bailmsg
+
+ ; Write error message, this assumes screen page 0
+.loop: lodsb
+ and al,al
+ jz .done
+ mov ah,0Eh ; Write to screen as TTY
+ mov bx,0007h ; Attribute
+ int 10h
+ jmp short .loop
+.done:
+ cbw ; AH <- 0
+.again: int 16h ; Wait for keypress
+ ; NB: replaced by int 18h if
+ ; chosen at install time..
+ int 19h ; And try once more to boot...
+.norge: jmp short .norge ; If int 19h returned; this is the end
+
;
; Truncate BP to MaxTransfer
;
;
; Error message on failure
;
-bailmsg: db 'Boot failed', 0Dh, 0Ah, 0
-
-;
-; EBIOS disk address packet
-;
- align 4, db 0
-dapa:
- dw 16 ; Packet size
-.count: dw 0 ; Block count
-.off: dw 0 ; Offset of buffer
-.seg: dw 0 ; Segment of buffer
-.lba: dd 0 ; LBA (LSW)
- dd 0 ; LBA (MSW)
-
-
-%if 1
-bs_checkpt_off equ ($-$$)
-%ifndef DEPEND
-%if bs_checkpt_off > 1F8h
-%error "Boot sector overflow"
-%endif
-%endif
+bailmsg: db 'Boot error', 0Dh, 0Ah, 0
+ ; This fails if the boot sector overflows
zb 1F8h-($-$$)
-%endif
+
FirstSector dd 0xDEADBEEF ; Location of sector 1
MaxTransfer dw 0x007F ; Max transfer size
-bootsignature dw 0AA55h
+
+; This field will be filled in 0xAA55 by the installer, but we abuse it
+; to house a pointer to the INT 16h instruction at
+; kaboom.again, which gets patched to INT 18h in RAID mode.
+bootsignature dw kaboom.again-bootsec
;
; ===========================================================================
align 8, db 0
ldlinux_magic dd LDLINUX_MAGIC
- dd HEXDATE
+ dd LDLINUX_MAGIC^HEXDATE
;
; This area is patched by the installer. It is found by looking for
SectorPtrs times 64 dd 0
ldlinux_ent:
-;
+;
; Note that some BIOSes are buggy and run the boot sector at 07C0:0000
; instead of 0000:7C00 and the like. We don't want to add anything
; more to the boot sector, so it is written to not assume a fixed
call writestr
;
-; Patch disk error handling
+; Tell the user if we're using EBIOS or CBIOS
;
- mov word [xint13.disk_error+1],do_disk_error-(xint13.disk_error+3)
+print_bios:
+ mov si,cbios_name
+ cmp byte [getlinsec.jmp+1],(getlinsec_ebios-(getlinsec.jmp+2))
+ jne .cbios
+ mov si,ebios_name
+.cbios:
+ mov [BIOSName],si
+ call writestr
+
+ section .bss
+%define HAVE_BIOSNAME 1
+BIOSName resw 1
+ section .text
;
; Now we read the rest of LDLINUX.SYS. Don't bother loading the first
; sector again, though.
dec cx
jz .chunk_ready
inc edx ; Next linear sector
- cmp [esi],edx ; Does it match
+ cmp [si],edx ; Does it match
jnz .chunk_ready ; If not, this is it
- add esi,4 ; If so, add sector to chunk
+ add si,4 ; If so, add sector to chunk
jmp short .make_chunk
.chunk_ready:
; -----------------------------------------------------------------------------
;
+;
+; writestr: write a null-terminated string to the console
+; This assumes we're on page 0. This is only used for early
+; messages, so it should be OK.
+;
+writestr:
+.loop: lodsb
+ and al,al
+ jz .return
+ mov ah,0Eh ; Write to screen as TTY
+ mov bx,0007h ; Attribute
+ int 10h
+ jmp short .loop
+.return: ret
+
+
; getlinsecsr: save registers, call getlinsec, restore registers
;
getlinsecsr: pushad
ret
;
-; This routine captures disk errors, and tries to decide if it is
-; time to reduce the transfer size.
+; Checksum error message
;
-do_disk_error:
- cmp ah,42h
- je .ebios
- shr al,1 ; Try reducing the transfer size
- mov [MaxTransfer],al
- jz kaboom ; If we can't, we're dead...
- jmp xint13 ; Try again
-.ebios:
- push ax
- mov ax,[si+2]
- shr ax,1
- mov [MaxTransfer],ax
- mov [si+2],ax
- pop ax
- jmp xint13
+checksumerr_msg db ' Load error - ', 0 ; Boot failed appended
;
-; Checksum error message
+; BIOS type string
;
-checksumerr_msg db 'Load error - ', 0 ; Boot failed appended
+cbios_name db 'CBIOS', 0
+ebios_name db 'EBIOS', 0
;
; Debug routine
rl_checkpt equ $ ; Must be <= 8000h
rl_checkpt_off equ ($-$$)
-%if 0 ; ndef DEPEND
+%ifndef DEPEND
%if rl_checkpt_off > 400h
%error "Sector 1 overflow"
%endif
.have_secs:
mov [TotalSectors],edx
- mov eax,[bsHidden] ; Hidden sectors aren't included
- add edx,eax
- mov [EndSector],edx
-
- add eax,[bxResSectors]
+ mov eax,[bxResSectors]
mov [FAT],eax ; Beginning of FAT
mov edx,[bxFATsecs]
and dx,dx
mov [RootDir],eax ; For FAT12/16 == root dir location
mov edx,[bxRootDirEnts]
- add dx,512-32
- shr dx,9-5
+ add dx,SECTOR_SIZE/32-1
+ shr dx,SECTOR_SHIFT-5
mov [RootDirSize],edx
add eax,edx
mov [DataArea],eax ; Beginning of data area
bsr cx,ax
mov [ClustShift],cl
push cx
- add cl,9
+ add cl,SECTOR_SHIFT
mov [ClustByteShift],cl
pop cx
dec ax
mov [ClustMask],eax
inc ax
- shl eax,9
+ shl eax,SECTOR_SHIFT
mov [ClustSize],eax
;
; FAT12, FAT16 or FAT28^H^H32? This computation is fscking ridiculous.
;
getfattype:
- mov eax,[EndSector]
+ mov eax,[TotalSectors]
sub eax,[DataArea]
shr eax,cl ; cl == ClustShift
mov cl,nextcluster_fat12-(nextcluster+2)
; Common initialization code
;
%include "cpuinit.inc"
+%include "init.inc"
;
-; Clear Files structures
-;
- mov di,Files
- mov cx,(MAX_OPEN*open_file_t_size)/4
- xor eax,eax
- rep stosd
-
-;
-; Initialization that does not need to go into the any of the pre-load
-; areas
+; Initialize the metadata cache
;
- ; Now set up screen parameters
- call adjust_screen
-
- ; Wipe the F-key area
- mov al,NULLFILE
- mov di,FKeyName
- mov cx,10*(1 << FILENAME_MAX_LG2)
- rep stosb
+ call initcache
;
; Now, everything is "up and running"... patch kaboom for more
; to take'm out. In fact, we may want to put them back if we're going
; to boot ELKS at some point.
;
- mov si,linuxauto_cmd ; Default command: "linux auto"
- mov di,default_cmd
- mov cx,linuxauto_len
- rep movsb
-
- mov di,KbdMap ; Default keymap 1:1
- xor al,al
- inc ch ; CX <- 256
-mkkeymap: stosb
- inc al
- loop mkkeymap
;
; Load configuration file
;
- mov di,syslinux_cfg
+ mov si,config_name ; Save configuration file name
+ mov di,ConfigName
+ call strcpy
+
+ mov di,syslinux_cfg1
+ call open
+ jnz .config_open
+ mov di,syslinux_cfg2
+ call open
+ jnz .config_open
+ mov di,syslinux_cfg3
call open
jz no_config_file
+.config_open:
+ 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
%include "ui.inc"
;
-; Linux kernel loading code is common.
-;
-%include "runkernel.inc"
-
-;
-; COMBOOT-loading code
-;
-%include "comboot.inc"
-%include "com32.inc"
-%include "cmdline.inc"
-
-;
-; Boot sector loading code
-;
-%include "bootsect.inc"
-
-;
-; abort_check: let the user abort with <ESC> or <Ctrl-C>
-;
-abort_check:
- call pollchar
- jz ac_ret1
- pusha
- call getchar
- cmp al,27 ; <ESC>
- je ac_kill
- cmp al,3 ; <Ctrl-C>
- jne ac_ret2
-ac_kill: mov si,aborted_msg
-
-;
-; abort_load: Called by various routines which wants to print a fatal
-; error message and return to the command prompt. Since this
-; may happen at just about any stage of the boot process, assume
-; our state is messed up, and just reset the segment registers
-; and the stack forcibly.
-;
-; SI = offset (in _text) of error message to print
-;
-abort_load:
- mov ax,cs ; Restore CS = DS = ES
- mov ds,ax
- mov es,ax
- cli
- mov sp,StackBuf-2*3 ; Reset stack
- mov ss,ax ; Just in case...
- sti
- call cwritestr ; Expects SI -> error msg
-al_ok: jmp enter_command ; Return to command prompt
-;
-; End of abort_check
-;
-ac_ret2: popa
-ac_ret1: ret
-
-;
; allocate_file: Allocate a file structure
;
; If successful:
ret
;
-; searchdir:
-; Search the root directory for a pre-mangled filename in DS:DI.
+; 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
-; DX:AX = file length in bytes
+; EAX = file length (MAY BE ZERO!)
+; DL = file attributes
; If unsuccessful
; ZF set
;
-searchdir:
+search_dos_dir:
+ push bx
call allocate_file
jnz .alloc_failure
+ push cx
push gs
push es
push ds
pop es ; ES = DS
- mov edx,[RootDir] ; First root directory sector
-
.scansector:
- mov eax,edx
+ ; EAX <- directory sector to scan
call getcachesector
; GS:SI now points to this sector
.scanentry:
cmp byte [gs:si],0
jz .failure ; Hit directory high water mark
+ test byte [gs:si+11],8 ; Ignore volume labels and
+ ; VFAT long filename entries
+ jnz .nomatch
push cx
push si
push di
+ mov di,MangledBuf
mov cx,11
gs repe cmpsb
pop di
pop si
pop cx
jz .found
+.nomatch:
add si,32
loop .scanentry
.failure:
pop es
pop gs
+ pop cx
.alloc_failure:
- xor ax,ax ; ZF <- 1
+ 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
- jz .failure ; Zero-length file
- mov [bx+4],eax
+ mov [bx+4],eax ; Sector count
mov cl,[ClustShift]
mov dx,[gs:si+20] ; High cluster word
mov dx,[gs:si+26] ; Low cluster word
sub edx,2
shl edx,cl
+ add edx,[DataArea]
mov [bx],edx ; Starting sector
- mov edx,eax
- shr edx,16 ; 16-bitism, sigh
- mov si,bx
- and eax,eax ; ZF <- 0
+ 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
;
-; writechr: Write a single character in AL to the console without
-; mangling any registers; handle video pages correctly.
+; close_file:
+; Deallocates a file structure (pointer in SI)
+; Assumes CS == DS.
;
-writechr:
- call write_serial ; write to serial port if needed
- pushfd
- pushad
- mov ah,0Eh
- mov bl,07h ; attribute
- mov bh,[cs:BIOS_page] ; current page
- int 10h
- popad
- popfd
+close_file:
+ and si,si
+ jz .closed
+ mov dword [si],0 ; First dword == file_left
+.closed: ret
+
+;
+; searchdir:
+;
+; Open a file
+;
+; On entry:
+; DS:DI = filename
+; If successful:
+; ZF clear
+; SI = file pointer
+; DX:AX or 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
+ pop eax ; <A> Current directory sector
+
+ 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 edx,eax
+ shr edx,16 ; Old 16-bit remnant...
+ 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
+
+.badfile:
+ xor eax,eax
+ mov [si],eax ; Free file structure
+
+.notfound:
+ xor eax,eax
+ xor dx,dx
ret
+ section .bss
+ alignb 4
+CurrentDir resd 1 ; Current directory
+PrevDir resd 1 ; Last scanned directory
+
+ section .text
+
;
;
; kaboom2: once everything is loaded, replace the part of kaboom
kaboom2:
mov si,err_bootfailed
call cwritestr
+ 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 DOS filename pointed to by DS:SI into a buffer pointed
-; to by ES:DI; ends on encountering any whitespace
+; 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.
+; Assumes CS == DS == ES.
+;
+
+mangle_dos_name:
+ pusha
+ mov di,MangledBuf
+
mov cx,11 ; # of bytes to write
-mn_loop:
+.loop:
lodsb
cmp al,' ' ; If control or space, end
- jna mn_end
+ jna .end
+ cmp al,'/' ; Slash, too
+ je .end
cmp al,'.' ; Period -> space-fill
- je mn_is_period
+ je .is_period
cmp al,'a'
- jb mn_not_lower
+ jb .not_lower
cmp al,'z'
- ja mn_not_uslower
+ ja .not_uslower
sub al,020h
- jmp short mn_not_lower
-mn_is_period: mov al,' ' ; We need to space-fill
-mn_period_loop: cmp cx,3 ; If <= 3 characters left
- jbe mn_loop ; Just ignore it
+ jmp short .not_lower
+.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 period
- loop mn_period_loop ; Dec CX and (always) jump
-mn_not_uslower: cmp al,ucase_low
- jb mn_not_lower
+ loop .period_loop ; Dec CX and (always) jump
+.not_uslower: cmp al,ucase_low
+ jb .not_lower
cmp al,ucase_high
- ja mn_not_lower
+ ja .not_lower
mov bx,ucase_tab-ucase_low
- cs xlatb
-mn_not_lower: stosb
- loop mn_loop ; Don't continue if too long
-mn_end:
+ xlatb
+.not_lower: stosb
+ loop .loop ; Don't continue if too long
+.end:
mov al,' ' ; Space-fill name
rep stosb ; Doesn't do anything if CX=0
+ popa
ret ; Done
+ section .bss
+MangledBuf resb 11
+
+ section .text
;
-; Upper-case table for extended characters; this is technically code page 865,
+; Case tables for extended characters; this is technically code page 865,
; but code page 437 users will probably not miss not being able to use the
; cent sign in kernel images too much :-)
;
; The table only covers the range 129 to 164; the rest we can deal with.
;
+ section .data
+
ucase_low equ 129
ucase_high equ 164
ucase_tab db 154, 144, 'A', 142, 'A', 143, 128, 'EEEIII'
db 142, 143, 144, 146, 146, 'O', 153, 'OUUY', 153, 154
db 157, 156, 157, 158, 159, 'AIOU', 165
-;
-; 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:
- push si ; Save pointer to original name
- mov cx,8
- mov bp,di
-un_copy_body: lodsb
- call lower_case
- stosb
- cmp al,' '
- jbe un_cb_space
- mov bp,di ; Position of last nonblank+1
-un_cb_space: loop un_copy_body
- mov di,bp
- mov al,'.' ; Don't save
- stosb
- mov cx,3
-un_copy_ext: lodsb
- call lower_case
- stosb
- cmp al,' '
- jbe un_ce_space
- mov bp,di
-un_ce_space: loop un_copy_ext
- mov di,bp
- mov byte [es:di], 0
- pop si
- ret
-
-;
-; lower_case: Lower case a character in AL
-;
-lower_case:
- cmp al,'A'
- jb lc_ret
- cmp al,'Z'
- ja lc_1
- or al,20h
- ret
-lc_1: cmp al,lcase_low
- jb lc_ret
- cmp al,lcase_high
- ja lc_ret
- push bx
- mov bx,lcase_tab-lcase_low
- cs xlatb
- pop bx
-lc_ret: ret
-
+ section .text
;
; getfssec_edx: Get multiple sectors from a file
;
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 DI = how far into 64K block we are
- neg ax ; Bytes left in 64K block
- shr ax,9 ; Sectors left in 64K block
+ 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...
- lea eax,[edx+1] ; Linearly next sector
+ mov eax,edx ; Current sector
+ inc edx ; Predict it's the linearly next sector
call nextsector
jc .do_read
- cmp edx,eax
+ cmp edx,eax ; Did it match?
jz .getseccnt
.do_read:
- mov eax,edx
+ pop eax ; Starting sector pointer
call getlinsecsr
lea eax,[eax+ebp-1] ; This is the last sector actually read
shl bp,9
push si
mov edx,edi
shr edi,1
+ pushf ; Save the shifted-out LSB (=CF)
add edx,edi
mov eax,edx
shr eax,9
mov bx,dx
and bx,1FFh
mov ch,[gs:si+bx]
- test di,1
- jz .even
+ popf
+ jnc .even
shr cx,4
.even: and cx,0FFFh
movzx edi,cx
;
; 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.
+; of the same filesystem object, which may be the root
+; directory or a cluster chain. Returns EOF.
;
-; Assumes CS == DS.
+; Assumes CS == DS.
;
nextsector:
push edi
;
getfatsector:
add eax,[FAT] ; FAT starting address
- ; Fall through
-
-;
-; getcachesector: Check for a particular sector (EAX) in the sector cache,
-; and if it is already there, return a pointer in GS:SI
-; otherwise load it and return said pointer.
-;
-; Assumes CS == DS.
-;
-getcachesector:
- push cx
- mov si,cache_seg
- mov gs,si
- mov si,CachePtrs ; Sector cache pointers
- mov cx,65536/SECTOR_SIZE
-.search:
- cmp eax,[si]
- jz .hit
- add si,4
- loop .search
-
-.miss:
- ; Need to load it. Highly inefficient cache replacement
- ; algorithm: Least Recently Written (LRW)
- push bx
- push es
- push gs
- pop es
- mov bx,[NextCacheSlot]
- inc bx
- and bx,(1 << (16-SECTOR_SHIFT))-1
- mov [NextCacheSlot],bx
- shl bx,2
- mov [CachePtrs+bx],eax
- shl bx,SECTOR_SHIFT-2
- mov si,bx
- pushad
- call getonesec
- popad
- pop es
- pop bx
- pop cx
- ret
-
-.hit: ; We have it; get the pointer
- sub si,CachePtrs
- shl si,SECTOR_SHIFT-2
- pop cx
- ret
+ jmp getcachesector
; -----------------------------------------------------------------------------
; Common modules
%include "getc.inc" ; getc et al
%include "conio.inc" ; Console I/O
+%include "plaincon.inc" ; writechr
%include "writestr.inc" ; String output
+%include "configinit.inc" ; Initialize configuration
%include "parseconfig.inc" ; High-level config file handling
%include "parsecmd.inc" ; Low-level config file handling
%include "bcopy32.inc" ; 32-bit bcopy
%include "graphics.inc" ; VGA graphics
%include "highmem.inc" ; High memory sizing
%include "strcpy.inc" ; strcpy()
+%include "cache.inc" ; Metadata disk cache
+%include "adv.inc" ; Auxillary Data Vector
; -----------------------------------------------------------------------------
; Begin data section
; -----------------------------------------------------------------------------
-;
-; Lower-case table for codepage 865
-;
-lcase_low equ 128
-lcase_high equ 165
-lcase_tab db 135, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138
- db 139, 140, 141, 132, 134, 130, 145, 145, 147, 148, 149
- db 150, 151, 152, 148, 129, 155, 156, 155, 158, 159, 160
- db 161, 162, 163, 164, 164
-
+ section .data
copyright_str db ' Copyright (C) 1994-', year, ' H. Peter Anvin'
db CR, LF, 0
-boot_prompt db 'boot: ', 0
-wipe_char db BS, ' ', BS, 0
-err_notfound db 'Could not find kernel image: ',0
-err_notkernel db CR, LF, 'Invalid or corrupt kernel image.', CR, LF, 0
-err_noram db 'It appears your computer has less than '
- asciidec dosram_k
- db 'K of low ("DOS")'
- db CR, LF
- db 'RAM. Linux needs at least this amount to boot. If you get'
- db CR, LF
- db 'this message in error, hold down the Ctrl key while'
- db CR, LF
- db 'booting, and I will take your word for it.', CR, LF, 0
-err_badcfg db 'Unknown keyword in syslinux.cfg.', CR, LF, 0
-err_noparm db 'Missing parameter in syslinux.cfg.', CR, LF, 0
-err_noinitrd db CR, LF, 'Could not find ramdisk image: ', 0
-err_nohighmem db 'Not enough memory to load specified kernel.', CR, LF, 0
-err_highload db CR, LF, 'Kernel transfer failure.', CR, LF, 0
-err_oldkernel db 'Cannot load a ramdisk with an old kernel image.'
- db CR, LF, 0
-err_notdos db ': attempted DOS system call', CR, LF, 0
-err_comlarge db 'COMBOOT image too large.', CR, LF, 0
-err_a20 db CR, LF, 'A20 gate not responding!', CR, LF, 0
err_bootfailed db CR, LF, 'Boot failed: please change disks and press '
db 'a key to continue.', CR, LF, 0
-ready_msg db 'Ready.', CR, LF, 0
-crlfloading_msg db CR, LF
-loading_msg db 'Loading ', 0
-dotdot_msg db '.'
-dot_msg db '.', 0
-aborted_msg db ' aborted.' ; Fall through to crlf_msg!
-crlf_msg db CR, LF
-null_msg db 0
-crff_msg db CR, FF, 0
-syslinux_cfg db 'SYSLINUXCFG' ; Mangled form
-ConfigName db 'syslinux.cfg',0 ; Unmangled form
-%if IS_MDSLINUX
-manifest db 'MANIFEST '
-%endif
+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
+
;
; Command line options we'd like to take a look at
;
;
; Extensions to search for (in *forward* order).
;
-exten_table: db 'CBT',0 ; COMBOOT (specific)
- db 'BSS',0 ; Boot Sector (add superblock)
- db 'BS ',0 ; Boot Sector
- db 'COM',0 ; COMBOOT (same as DOS)
- db 'C32',0 ; COM32
+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
%ifdef debug ; This code for debugging only
debug_magic dw 0D00Dh ; Debug code sentinel
%endif
-AppendLen dw 0 ; Bytes in append= command
-OntimeoutLen dw 0 ; Bytes in ontimeout command
-OnerrorLen dw 0 ; Bytes in onerror command
-KbdTimeOut dw 0 ; Keyboard timeout (if any)
-CmdLinePtr dw cmd_line_here ; Command line advancing pointer
-initrd_flag equ $
-initrd_ptr dw 0 ; Initial ramdisk pointer/flag
-VKernelCtr dw 0 ; Number of registered vkernels
-ForcePrompt dw 0 ; Force prompt
-AllowImplicit dw 1 ; Allow implicit kernels
-AllowOptions dw 1 ; User-specified options allowed
-SerialPort dw 0 ; Serial port base (or 0 for no serial port)
-VGAFontSize dw 16 ; Defaults to 16 byte font
-UserFont db 0 ; Using a user-specified font
-ScrollAttribute db 07h ; White on black (for text mode)
alignb 4, db 0
BufSafe dw trackbufsize/SECTOR_SIZE ; Clusters we can load into trackbuf
-BufSafeSec dw trackbufsize/SECTOR_SIZE ; = how many sectors?
BufSafeBytes dw trackbufsize ; = how many bytes?
-EndOfGetCBuf dw getcbuf+trackbufsize ; = getcbuf+BufSafeBytes
%ifndef DEPEND
%if ( trackbufsize % SECTOR_SIZE ) != 0
%error trackbufsize must be a multiple of SECTOR_SIZE
%endif
%endif
-;
-; Stuff for the command line; we do some trickery here with equ to avoid
-; tons of zeros appended to our file and wasting space
-;
-linuxauto_cmd db 'linux auto',0
-linuxauto_len equ $-linuxauto_cmd
-boot_image db 'BOOT_IMAGE='
-boot_image_len equ $-boot_image
-
- align 4, db 0 ; Pad out any unfinished dword
-ldlinux_end equ $
-ldlinux_len equ $-ldlinux_magic
-
-; VGA font buffer at the end of memory (so loading a font works even
-; in graphics mode.)
-vgafontbuf equ 0E000h
-
-; This is a compile-time assert that we didn't run out of space
-%ifndef DEPEND
-%if (ldlinux_end-bootsec+7C00h) > vgafontbuf
-%error "Out of memory, better reorganize something..."
-%endif
-%endif
projects / profile / ivi / syslinux.git / blobdiff