diff options
Diffstat (limited to 'pxelinux.asm')
| -rw-r--r-- | pxelinux.asm | 568 |
1 files changed, 295 insertions, 273 deletions
diff --git a/pxelinux.asm b/pxelinux.asm index 6a6dd903..cdd5c2c1 100644 --- a/pxelinux.asm +++ b/pxelinux.asm @@ -243,6 +243,7 @@ HiLoadAddr resd 1 ; Address pointer for high load loop HighMemSize resd 1 ; End of memory pointer (bytes) KernelSize resd 1 ; Size of kernel (bytes) Stack resd 1 ; Pointer to reset stack +PXEEntry resd 1 ; !PXE API entry point RootDir equ $ ; Location of root directory RootDir1 resw 1 RootDir2 resw 1 @@ -296,6 +297,30 @@ InitRDCName resb MAX_FILENAME ; Unmangled initrd name MNameBuf resb 11 ; OBSOLETE InitRD resb 11 ; OBSOLETE + alignb 16 + ; BOOTP/DHCP packet buffer +bootp: +.opcode resb 1 ; BOOTP/DHCP "opcode" +.hardware resb 1 ; ARP hardware type +.hardlen resb 1 ; Hardware address length +.gatehops resb 1 ; Used by forwarders +.ident resd 1 ; Transaction ID +.seconds resw 1 ; Seconds elapsed +.flags resw 1 ; Broadcast flags +.cip resd 1 ; Client IP +.yip resd 1 ; "Your" IP +.sip resd 1 ; Next server IP +.gip resd 1 ; Relay agent IP +.macaddr resb 16 ; Client MAC address +.sname resb 64 ; Server name (optional) +.bootfile resb 128 ; Boot file name +.v_magic resd 1 ; DHCP magic cookie +.v_flags resd 1 ; DHCP flags +.v_pad resb 56 ; Vendor options padding + +bootp_size equ $-bootp + + section .text org 7C00h ; @@ -332,17 +357,24 @@ _start1: cmp ax,564Eh jne no_pxe - mov si,found_pxenv - call writestr - ; Okay, that gave us the PXENV+ structure, find !PXE ; structure from that cmp dword [es:bx], 'PXEN' jne no_pxe cmp word [es:bx+4], 'V+' jne no_pxe + + mov si,found_pxenv + call writestr + + mov si,apiver_str + call writestr + mov ax,[es:bx+6] + call writehex4 + call crlf + cmp word [es:bx+6], 0201h ; API version 2.1 or higher - jb no_pxe + jb old_api les bx,[es:bx+26h] ; !PXE structure pointer cmp dword [es:bx],'!PXE' je have_pxe @@ -351,7 +383,26 @@ no_pxe: mov si,err_nopxe call writestr jmp kaboom +old_api: ; Need to use a PXENV+ structure + mov si,using_pxenv_msg + call writestr + + mov eax,[es:bx+0Ah] ; PXE RM API + mov [PXENVEntry],eax + jmp short have_pxe_entry have_pxe: + mov eax,[es:bx+10h] + mov [PXEEntry],eax + +have_pxe_entry: mov si,pxeentry_msg + call writestr + mov ax,[PXENVEntry+2] + call writehex4 + mov al,':' + call writechr + mov ax,[PXENVEntry] + call writehex4 + call crlf ; ; Tell the user we got this far @@ -359,174 +410,148 @@ have_pxe: mov si,pxelinux_banner call writestr -.enough: jmp short .enough - + mov si,copyright_str + call writestr + ; -; ----------------------------------------------------------------------------- -; Subroutines that have to be in the first sector -; ----------------------------------------------------------------------------- +; Now attempt to get the BOOTP/DHCP packet that brought us life (and an IP +; address) ; -; getfssec: Get multiple clusters from a file, given the starting cluster. +query_bootp: mov ax,0DEADh ; Something bogus + + mov ax,ds + mov es,ax + mov di,pxe_bootp_query_pkt + mov bx,0071h ; PXENV_GET_CACHED_INFO + + call far [PXENVEntry] + jc .pxe_err + cmp ax,byte 0 + je .pxe_ok +.pxe_err: + mov si,err_pxefailed + call writestr + call writehex4 + call crlf + +.pxe_ok: mov si,myipaddr_msg + call writestr + mov eax,[bootp.yip] ; "Your" IP address + call writehex8 + mov al,' ' + call writechr + mov eax,[bootp.sip] ; Server IP address(?) + call writehex8 + mov al,' ' + call writechr + mov eax,[bootp.gip] ; Gateway IP address(?) + call writehex8 + call crlf + + ; Print the boot file + mov si,bootp.bootfile + call writestr + call crlf ; -; 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. +; Normalize ES = DS ; -; ES:BX -> Buffer -; SI -> Starting cluster number (2-based) -; CX -> Cluster count (0FFFFh = until end of file) + mov ax,ds + mov es,ax ; - ; 386 check -getfssec: -%if 0 -getfragment: xor bp,bp ; Fragment sector count - mov ax,si ; Get sector address - dec ax ; Convert to 0-based - dec ax - mul word [SecPerClust] - add ax,[DataArea1] - adc dx,[DataArea2] -getseccnt: ; See if we can read > 1 clust - add bp,[SecPerClust] - dec cx ; Reduce clusters left to find - mov di,si ; Predict next cluster +; Now, prepare some of the data structures +; + mov eax,[bootp.sip] + mov [pxe_tftp_open_pkt.sip],eax + +filename_cp: mov si,bootp.bootfile + mov di,pxe_tftp_open_pkt.filename + cld + xor cx,cx +.strcpy: lodsb + stosb + inc cx + and al,al + jnz .strcpy + std + dec di + mov si,di + mov al,'.' + repne scasb + jne .nodot inc di - call [NextCluster] - jc gfs_eof ; At EOF? - jcxz endfragment ; Or was it the last we wanted? - cmp si,di ; Is file continuous? - jz getseccnt ; Yes, we can get -endfragment: clc ; Not at EOF -gfs_eof: pushf ; Remember EOF or not - push si - push cx -gfs_getchunk: - push ax - push dx - mov ax,es ; Check for 64K boundaries. - mov cl,4 - shl ax,cl - add ax,bx - xor dx,dx - neg ax - jnz gfs_partseg - inc dx ; Full 64K segment -gfs_partseg: - div word [bsBytesPerSec] ; How many sectors fit? - mov si,bp - sub si,ax ; Compute remaining sectors - jbe gfs_lastchunk - mov bp,ax - pop dx - pop ax - call getlinsecsr - add ax,bp - adc dx,byte 0 - mov bp,si ; Remaining sector count - jmp short gfs_getchunk -gfs_lastchunk: pop dx - pop ax - call getlinsec - pop cx - pop si - popf - jcxz gfs_return ; If we hit the count limit - jnc getfragment ; If we didn't hit EOF -gfs_return: ret + jmp short .dot +.nodot: mov di,si +.dot: cld + ; Now di points to where we want to add stuff to the filename + mov al,'/' + stosb + mov cx,8 + mov eax,[bootp.yip] + bswap eax ; Convert to native byte order +.hexify_loop: rol eax,4 + push eax + and al,0Fh + cmp al,10 + jae .high +.low: add al,'0' + jmp short .char +.high: add al,'A'-10 +.char: stosb + pop eax + loop .hexify_loop ; -; getlinsecsr: save registers, call getlinsec, restore registers +; Begin looking for configuration file ; -getlinsecsr: push ax - push dx - push cx - push bp - push si - push di - call getlinsec - pop di - pop si - pop bp - pop cx - pop dx - pop ax - ret -%endif +config_scan: + mov cx,9 ; Up to 9 attempts -; -; nextcluster: Advance a cluster pointer in SI to the next cluster -; pointed at in the FAT tables (note: FAT12 assumed) -; Sets CF on return if end of file. -; -; The variable NextCluster gets set to the appropriate -; value here. -; -nextcluster_fat12: - push ax - push ds - mov ax,fat_seg - mov ds,ax - mov ax,si ; Multiply by 3/2 - shr ax,1 - pushf ; CF now set if odd - add si,ax - mov si,[si] - popf - jnc nc_even - shr si,1 ; Needed for odd only - shr si,1 - shr si,1 - shr si,1 -nc_even: - and si,0FFFh - cmp si,0FF0h ; Clears CF if at end of file - cmc ; But we want it SET... - pop ds - pop ax -nc_return: ret +.tryagain: mov byte [di],0 + cmp cx,byte 1 + jne .not_default + pusha + mov si,default_str + mov cx,default_len + rep movsb ; Copy "default" string + popa +.not_default: pusha + mov di,pxe_tftp_open_pkt + mov bx,0020h ; PXENV_TFTP_OPEN + call far [PXENVEntry] + jc .badness + cmp ax,byte 0 + jne .badness + cmp word [pxe_tftp_open_pkt.status],0 + je .success +.badness: popa + dec di + loop .tryagain ; -; FAT16 decoding routine. Note that a 16-bit FAT can be up to 128K, -; so we have to decide if we're in the "low" or the "high" 64K-segment... -; -nextcluster_fat16: - push ax - push ds - mov ax,fat_seg - shl si,1 - jnc .seg0 - mov ax,fat_seg+1000h -.seg0: mov ds,ax - mov si,[si] - cmp si,0FFF0h - cmc - pop ds - pop ax - ret -; -; Debug routine +; If we get here, no configuration file ; -%ifdef debug -safedumpregs: - cmp word [Debug_Magic],0D00Dh - jnz nc_return - jmp dumpregs -%endif -rl_checkpt equ $ ; Must be <= 400h +.success: popa + ; If we get here, we have an open TFTP connection to the config file -; ---------------------------------------------------------------------------- -; End of code and data that have to be in the first sector -; ---------------------------------------------------------------------------- +enough: mov si,enough_msg + call writestr + jmp kaboom +enough_msg: db 13,10,10,'End of implemented code.', 13, 10, 0 -all_read: ; -; Let the user (and programmer!) know we got this far. This used to be -; in Sector 1, but makes a lot more sense here. +; getfssec: Get multiple clusters from a file, given the starting cluster. ; - mov si,copyright_str - call writestr +; 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 +; SI -> Starting cluster number (2-based) +; CX -> Cluster count (0FFFFh = until end of file) +; + ; 386 check +; ; Check that no moron is trying to boot Linux on a 286 or so. According ; to Intel, the way to check is to see if the high 4 bits of the FLAGS ; register are either all stuck at 1 (8086/8088) or all stuck at 0 @@ -611,13 +636,6 @@ is_486: ; call adjust_screen ; -; Now, everything is "up and running"... patch kaboom for more -; verbosity and using the full screen system -; - mov byte [kaboom.patch],0e9h ; JMP NEAR - mov word [kaboom.patch+1],kaboom2-(kaboom.patch+3) - -; ; Now we're all set to start with our *real* business. First load the ; configuration file (if any) and parse it. ; @@ -945,7 +963,7 @@ enter_char: test byte [FuncFlag],1 get_char_2: jmp short get_char not_ascii: mov byte [FuncFlag],0 cmp al,0Dh ; Enter - je command_done + je near command_done cmp al,06h ; <Ctrl-F> je set_func_flag cmp al,08h ; Backspace @@ -1241,7 +1259,7 @@ kernel_sane: push ax sub [KernelClust],cx xor bx,bx pop si ; Cluster pointer on stack - call getfssec +; call getfssec jc near kernel_corrupt ; Failure in first 32K cmp word [es:bs_bootsign],0AA55h jne near kernel_corrupt ; Boot sec signature missing @@ -1486,7 +1504,7 @@ high_last_moby: sub [KernelClust],cx xor bx,bx ; Load at offset 0 pop si ; Restore cluster pointer - call getfssec +; call getfssec push si ; Save cluster pointer pushf ; Save EOF xor bx,bx @@ -1625,7 +1643,7 @@ is_comboot_image: mov bx,100h ; Load at <seg>:0100h mov cx,[ClustPerMoby] ; Absolute maximum # of clusters - call getfssec +; call getfssec xor di,di mov cx,64 ; 256 bytes (size of PSP) @@ -1935,7 +1953,7 @@ rd_last_moby: push word xfer_buf_seg ; Bounce buffer segment pop es push cx - call getfssec +; call getfssec pop cx push si ; Save cluster pointer mov esi,(xfer_buf_seg << 4) @@ -2009,20 +2027,6 @@ kaboom: .norge: jmp short .norge ; If int 19h returned; this is the end ; -; -; writestr: write a null-terminated string to the console -; -writestr: -wstr_1: lodsb - and al,al - jz .return - mov ah,0Eh ; Write to screen as TTY - mov bx,0007h ; White on black, current page - int 10h - jmp short wstr_1 -.return: ret - -; ; searchdir: Search the root directory for a pre-mangled filename in ; DS:DI. This routine is similar to the one in the boot ; sector, but is a little less Draconian when it comes to @@ -2080,7 +2084,7 @@ bf_ret: ret loadfont: mov bx,trackbuf ; The trackbuf is >= 16K; the part mov cx,[BufSafe] ; of a PSF file we care about is no - call getfssec ; more than 8K+4 bytes +; call getfssec ; more than 8K+4 bytes mov ax,[trackbuf] ; Magic number cmp ax,0436h @@ -2120,7 +2124,7 @@ loadkeys: mov bx,trackbuf mov cx,1 ; 1 cluster should be >= 256 bytes - call getfssec +; call getfssec mov si,trackbuf mov di,KbdMap @@ -2147,7 +2151,7 @@ get_msg_chunk: push ax ; DX:AX = length of file push dx mov bx,trackbuf mov cx,[BufSafe] - call getfssec +; call getfssec pop dx pop ax push si ; Save current cluster @@ -2290,27 +2294,68 @@ write_serial_str: ; writechr: call write_serial ; write to serial port if needed - pusha + pushad mov ah,0Eh mov bx,0007h ; white text on this page int 10h - popa + popad ret ; +; crlf: Print a newline +; +crlf: mov si,crlf_msg + ; Fall through + +; ; cwritestr: write a null-terminated string to the console, saving ; registers on entry. ; +; Note: writestr and cwritestr are distinct in SYSLINUX, not in PXELINUX +; cwritestr: - pusha + pushad .top: lodsb and al,al jz .end call writechr jmp short .top -.end: popa +.end: popad ret +writestr equ cwritestr + +; +; writehex[248]: Write a hex number in (AL, AX, EAX) to the console +; +writehex2: + pushad + rol eax,24 + mov cx,2 + jmp short writehex_common +writehex4: + pushad + rol eax,16 + mov cx,4 + jmp short writehex_common +writehex8: + pushad + mov cx,8 +writehex_common: +.loop: rol eax,4 + push eax + and al,0Fh + cmp al,10 + jae .high +.low: add al,'0' + jmp short .ischar +.high: add al,'A'-10 +.ischar: call writechr + pop eax + loop .loop + popad + ret + ; ; pollchar: check if we have an input character pending (ZF = 0) ; @@ -2371,13 +2416,17 @@ kaboom2: ; similar to the C library getc routine. Only one simultaneous ; use is supported. Note: "open" trashes the trackbuf. ; -; open: Input: mangled filename in DS:DI +; open: Input: filename in DS:DI ; Output: ZF set on file not found or zero length ; ; getc: Output: CF set on end of file ; Character loaded in AL ; open: + mov di,pxe_tftp_open_pkt + mov bx,0020h ; PXENV_TFTP_OPEN + call far [PXENVEntry] + call searchdir jz open_return pushf @@ -2415,7 +2464,7 @@ getc_oksize: sub [FClust],cx ; Reduce remaining clusters push es ; ES may be != DS, save old ES push ds ; Trackbuf is in DS, not ES pop es - call getfssec ; Load a trackbuf full of data +; call getfssec ; Load a trackbuf full of data mov [FNextClust],si ; Store new next pointer pop es ; Restore ES pop si ; SI -> newly loaded data @@ -2684,89 +2733,6 @@ gl_ret: pushf ; We want the last char to be space! gl_xret: popf ret - -%ifdef debug ; This code for debugging only -; -; dumpregs: Dumps the contents of all registers -; - assume ds:_text, es:NOTHING, fs:NOTHING, gs:NOTHING -dumpregs proc near ; When calling, IP is on stack - pushf ; Store flags - pusha - push ds - push es - push fs - push gs - push cs ; Set DS <- CS - pop ds - cld ; Clear direction flag - mov si,offset crlf_msg - call cwritestr - mov bx,sp - add bx,byte 26 - mov si,offset regnames - mov cx,2 ; 2*7 registers to dump -dump_line: push cx - mov cx,7 ; 7 registers per line -dump_reg: push cx - mov cx,4 ; 4 characters/register name -wr_reg_name: lodsb - call writechr - loop wr_reg_name - mov ax,ss:[bx] - dec bx - dec bx - call writehex - pop cx - loop dump_reg - mov al,0Dh ; <CR> - call writechr - mov al,0Ah ; <LF> - call writechr - pop cx - loop dump_line - pop gs - pop fs - pop es - pop ds - popa ; Restore the remainder - popf ; Restore flags - ret -dumpregs endp - -regnames db ' IP: FL: AX: CX: DX: BX: SP: BP: SI: DI: DS: ES: FS: GS:' - -; -; writehex: Writes a 16-bit hexadecimal number (in AX) -; -writehex proc near - push bx - push cx - mov cx,4 ; 4 numbers -write_hexdig: xor bx,bx - push cx - mov cx,4 ; 4 bits/digit -xfer_digit: shl ax,1 - rcl bx,1 - loop xfer_digit - push ax - mov ax,bx - or al,'0' - cmp al,'9' - jna ok_digit - add al,'A'-'0'-10 -ok_digit: call writechr - pop ax - pop cx - loop write_hexdig - pop cx - pop bx - ret -writehex endp - -debug_magic dw 0D00Dh - -%endif ; debug ; ; mangle_name: Mangle a DOS filename pointed to by DS:SI into a buffer pointed ; to by ES:DI; ends on encountering any whitespace @@ -2878,6 +2844,29 @@ lc_1: cmp al,lcase_low lc_ret: ret ; +; pxe_thunk +; +; Convert from the PXENV+ calling convention (BX, ES, DI) to the !PXE +; calling convention (using the stack.) +; +; This is called as a far routine so that we can just stick it into +; the PXENVEntry variable. +; +pxe_thunk: push es + push di + push bx + call far [PXEEntry] + add sp,byte 6 + cmp ax,byte 1 + cmc ; Set CF unless ax == 0 + retf + +; ---------------------------------------------------------------------------------- +; Begin data section +; ---------------------------------------------------------------------------------- + + +; ; Lower-case table for codepage 865 ; lcase_low equ 128 @@ -2926,7 +2915,12 @@ err_bootfailed db 0Dh, 0Ah, 'Boot failed: please change disks and press ' db 'a key to continue.', 0Dh, 0Ah, 0 bailmsg equ err_bootfailed err_nopxe db 'Cannot find !PXE structure, I want my mommy!' ,0Dh, 0Ah, 0 +err_pxefailed db 'PXE API call failed, error ', 0 found_pxenv db 'Found PXENV+ structure', 0Dh, 0Ah, 0 +using_pxenv_msg db 'PXE API 2.0 detected, using PXENV+ structure', 0Dh, 0Ah, 0 +apiver_str db 'PXE API version is ',0 +pxeentry_msg db 'PXE entry point found (we hope) at ', 0 +myipaddr_msg db 'My IP address seems to be ',0 loading_msg db 'Loading ', 0 dotdot_msg db '.' dot_msg db '.', 0 @@ -2934,8 +2928,9 @@ aborted_msg db ' aborted.' ; Fall through to crlf_msg! crlf_msg db 0Dh, 0Ah, 0 crff_msg db 0Dh, 0Ch, 0 syslinux_cfg db 'SYSLINUXCFG' +default_str db 'default', 0 +default_len equ ($-default_str) pxelinux_banner db 0Dh, 0Ah, 'PXELINUX ', version_str, ' ', date, ' ', 0 - db 0Dh, 0Ah, 1Ah ; EOF if we "type" this in DOS ; ; Command line options we'd like to take a look at @@ -2946,7 +2941,8 @@ initrd_cmd_len equ 7 ; ; Config file keyword table ; - align 2 + align 2, db 0 + keywd_table db 'ap' ; append db 'de' ; default db 'ti' ; timeout @@ -2975,6 +2971,7 @@ keywd_table db 'ap' ; append ; extension, needed for error messages. The exten_table is shifted so ; the table is 1-based; this is because a "loop" cx is used as index. ; + align 4, db 0 exten_table: OrigKernelExt: dd 0 ; Original extension db 'COM',0 ; COMBOOT (same as DOS) @@ -2983,6 +2980,31 @@ OrigKernelExt: dd 0 ; Original extension db 'CBT',0 ; COMBOOT (specific) exten_count equ (($-exten_table) >> 2) - 1 ; Number of alternates + +; +; PXENV entry point. If we use the !PXE API, this will point to a thunk +; function that converts to the !PXE calling convention. +; +PXENVEntry dw pxe_thunk,0 + +; +; PXE query packets partially filled in +; +pxe_bootp_query_pkt: +.status: dw 0 ; Status +.packettype: dw 2 ; DHCPACK packet +.buffersize: dw bootp_size ; Packet size +.buffer: dw bootp, 0 ; seg:off of buffer +.bufferlimit: dw 0 ; Unused + +pxe_tftp_open_pkt: +.status: dw 0 ; Status +.sip dd 0 ; Server IP +.gip dd 0 ; Gateway IP +.filename times 128 db 0 ; Input filename +.tftpport dw 69 ; TFTP port +.packetsize dw 1024 ; Packet size + ; ; Misc initialized (data) variables ; |