1 ; -*- fundamental -*- (asm-mode sucks)
2 ; ****************************************************************************
6 ; A program to boot Linux kernels off a TFTP server using the Intel PXE
7 ; network booting API. It is based on the SYSLINUX boot loader for
10 ; Copyright 1994-2008 H. Peter Anvin - All Rights Reserved
12 ; This program is free software; you can redistribute it and/or modify
13 ; it under the terms of the GNU General Public License as published by
14 ; the Free Software Foundation, Inc., 53 Temple Place Ste 330,
15 ; Boston MA 02111-1307, USA; either version 2 of the License, or
16 ; (at your option) any later version; incorporated herein by reference.
18 ; ****************************************************************************
25 ; Some semi-configurable constants... change on your own risk.
28 FILENAME_MAX_LG2 equ 7 ; log2(Max filename size Including final null)
29 FILENAME_MAX equ (1 << FILENAME_MAX_LG2)
30 NULLFILE equ 0 ; Zero byte == null file name
31 NULLOFFSET equ 4 ; Position in which to look
32 REBOOT_TIME equ 5*60 ; If failure, time until full reset
33 %assign HIGHMEM_SLOP 128*1024 ; Avoid this much memory near the top
34 MAX_OPEN_LG2 equ 5 ; log2(Max number of open sockets)
35 MAX_OPEN equ (1 << MAX_OPEN_LG2)
36 PKTBUF_SIZE equ (65536/MAX_OPEN) ; Per-socket packet buffer size
37 TFTP_PORT equ htons(69) ; Default TFTP port
38 PKT_RETRY equ 6 ; Packet transmit retry count
39 PKT_TIMEOUT equ 12 ; Initial timeout, timer ticks @ 55 ms
40 ; Desired TFTP block size
41 ; For Ethernet MTU is normally 1500. Unfortunately there seems to
42 ; be a fair number of networks with "substandard" MTUs which break.
43 ; The code assumes TFTP_LARGEBLK <= 2K.
45 TFTP_LARGEBLK equ (TFTP_MTU-20-8-4) ; MTU - IP hdr - UDP hdr - TFTP hdr
46 ; Standard TFTP block size
47 TFTP_BLOCKSIZE_LG2 equ 9 ; log2(bytes/block)
48 TFTP_BLOCKSIZE equ (1 << TFTP_BLOCKSIZE_LG2)
49 %assign USE_PXE_PROVIDED_STACK 1 ; Use stack provided by PXE?
51 SECTOR_SHIFT equ TFTP_BLOCKSIZE_LG2
52 SECTOR_SIZE equ TFTP_BLOCKSIZE
55 ; This is what we need to do when idle
56 ; *** This is disabled because some PXE stacks wait for unacceptably
57 ; *** long if there are no packets receivable.
59 %define HAVE_IDLE 0 ; idle is not a noop
78 ; TFTP operation codes
80 TFTP_RRQ equ htons(1) ; Read request
81 TFTP_WRQ equ htons(2) ; Write request
82 TFTP_DATA equ htons(3) ; Data packet
83 TFTP_ACK equ htons(4) ; ACK packet
84 TFTP_ERROR equ htons(5) ; ERROR packet
85 TFTP_OACK equ htons(6) ; OACK packet
90 TFTP_EUNDEF equ htons(0) ; Unspecified error
91 TFTP_ENOTFOUND equ htons(1) ; File not found
92 TFTP_EACCESS equ htons(2) ; Access violation
93 TFTP_ENOSPACE equ htons(3) ; Disk full
94 TFTP_EBADOP equ htons(4) ; Invalid TFTP operation
95 TFTP_EBADID equ htons(5) ; Unknown transfer
96 TFTP_EEXISTS equ htons(6) ; File exists
97 TFTP_ENOUSER equ htons(7) ; No such user
98 TFTP_EOPTNEG equ htons(8) ; Option negotiation failure
101 ; The following structure is used for "virtual kernels"; i.e. LILO-style
102 ; option labels. The options we permit here are `kernel' and `append
103 ; Since there is no room in the bottom 64K for all of these, we
104 ; stick them in high memory and copy them down before we need them.
107 vk_vname: resb FILENAME_MAX ; Virtual name **MUST BE FIRST!**
108 vk_rname: resb FILENAME_MAX ; Real name
109 vk_ipappend: resb 1 ; "IPAPPEND" flag
110 vk_type: resb 1 ; Type of file
113 vk_append: resb max_cmd_len+1 ; Command line
115 vk_end: equ $ ; Should be <= vk_size
119 ; Segment assignments in the bottom 640K
120 ; 0000h - main code/data segment (and BIOS segment)
122 real_mode_seg equ 3000h
123 pktbuf_seg equ 2000h ; Packet buffers segments
124 xfer_buf_seg equ 1000h ; Bounce buffer for I/O to high mem
125 comboot_seg equ real_mode_seg ; COMBOOT image loading zone
128 ; BOOTP/DHCP packet pattern
132 .opcode resb 1 ; BOOTP/DHCP "opcode"
133 .hardware resb 1 ; ARP hardware type
134 .hardlen resb 1 ; Hardware address length
135 .gatehops resb 1 ; Used by forwarders
136 .ident resd 1 ; Transaction ID
137 .seconds resw 1 ; Seconds elapsed
138 .flags resw 1 ; Broadcast flags
139 .cip resd 1 ; Client IP
140 .yip resd 1 ; "Your" IP
141 .sip resd 1 ; Next server IP
142 .gip resd 1 ; Relay agent IP
143 .macaddr resb 16 ; Client MAC address
144 .sname resb 64 ; Server name (optional)
145 .bootfile resb 128 ; Boot file name
146 .option_magic resd 1 ; Vendor option magic cookie
147 .options resb 1260 ; Vendor options
150 BOOTP_OPTION_MAGIC equ htonl(0x63825363) ; See RFC 2132
153 ; TFTP connection data structure. Each one of these corresponds to a local
154 ; UDP port. The size of this structure must be a power of 2.
155 ; HBO = host byte order; NBO = network byte order
156 ; (*) = written by options negotiation code, must be dword sized
159 tftp_localport resw 1 ; Local port number (0 = not in use)
160 tftp_remoteport resw 1 ; Remote port number
161 tftp_remoteip resd 1 ; Remote IP address
162 tftp_filepos resd 1 ; Bytes downloaded (including buffer)
163 tftp_filesize resd 1 ; Total file size(*)
164 tftp_blksize resd 1 ; Block size for this connection(*)
165 tftp_bytesleft resw 1 ; Unclaimed data bytes
166 tftp_lastpkt resw 1 ; Sequence number of last packet (NBO)
167 tftp_dataptr resw 1 ; Pointer to available data
168 resw 2 ; Currently unusued
169 ; At end since it should not be zeroed on socked close
170 tftp_pktbuf resw 1 ; Packet buffer offset
173 %if (open_file_t_size & (open_file_t_size-1))
174 %error "open_file_t is not a power of 2"
178 ; ---------------------------------------------------------------------------
180 ; ---------------------------------------------------------------------------
183 ; Memory below this point is reserved for the BIOS and the MBR
186 trackbufsize equ 8192
187 trackbuf resb trackbufsize ; Track buffer goes here
190 alignb open_file_t_size
191 Files resb MAX_OPEN*open_file_t_size
194 BootFile resb 256 ; Boot file from DHCP packet
195 PathPrefix resb 256 ; Path prefix derived from boot file
196 DotQuadBuf resb 16 ; Buffer for dotted-quad IP address
197 IPOption resb 80 ; ip= option buffer
198 InitStack resd 1 ; Pointer to reset stack (SS:SP)
199 PXEStack resd 1 ; Saved stack during PXE call
203 RebootTime resd 1 ; Reboot timeout, if set by option
204 StrucPtr resd 1 ; Pointer to PXENV+ or !PXE structure
205 APIVer resw 1 ; PXE API version found
206 IPOptionLen resw 1 ; Length of IPOption
207 IdleTimer resw 1 ; Time to check for ARP?
208 LocalBootType resw 1 ; Local boot return code
209 PktTimeout resw 1 ; Timeout for current packet
210 RealBaseMem resw 1 ; Amount of DOS memory after freeing
211 OverLoad resb 1 ; Set if DHCP packet uses "overloading"
212 DHCPMagic resb 1 ; PXELINUX magic flags
214 ; The relative position of these fields matter!
215 MAC_MAX equ 32 ; Handle hardware addresses this long
216 MACLen resb 1 ; MAC address len
217 MACType resb 1 ; MAC address type
218 MAC resb MAC_MAX+1 ; Actual MAC address
219 BOOTIFStr resb 7 ; Space for "BOOTIF="
220 MACStr resb 3*(MAC_MAX+1) ; MAC address as a string
222 ; The relative position of these fields matter!
223 UUIDType resb 1 ; Type byte from DHCP option
224 UUID resb 16 ; UUID, from the PXE stack
225 UUIDNull resb 1 ; dhcp_copyoption zero-terminates
228 ; PXE packets which don't need static initialization
231 pxe_unload_stack_pkt:
232 .status: resw 1 ; Status
233 .reserved: resw 10 ; Reserved
234 pxe_unload_stack_pkt_len equ $-pxe_unload_stack_pkt
237 ; BOOTP/DHCP packet buffer
241 packet_buf resb 2048 ; Transfer packet
242 packet_buf_size equ $-packet_buf
246 ; PXELINUX needs more BSS than the other derivatives;
247 ; therefore we relocate it from 7C00h on startup.
249 StackBuf equ $ ; Base of stack if we use our own
252 ; Primary entry point.
256 pushfd ; Paranoia... in case of return to PXE
257 pushad ; ... save as much state as possible
268 %if TEXT_START != 0x7c00
269 ; This is uglier than it should be, but works around
270 ; some NASM 0.98.38 bugs.
271 mov di,section..bcopy32.start
272 add di,__bcopy_size-4
273 lea si,[di-(TEXT_START-7C00h)]
274 lea cx,[di-(TEXT_START-4)]
276 std ; Overlapping areas, copy backwards
280 jmp 0:_start1 ; Canonicalize address
283 les bx,[bp+48] ; ES:BX -> !PXE or PXENV+ structure
285 ; That is all pushed onto the PXE stack. Save the pointer
286 ; to it and switch to an internal stack.
290 %if USE_PXE_PROVIDED_STACK
291 ; Apparently some platforms go bonkers if we
292 ; set up our own stack...
300 sti ; Stack set up and ready
304 ; Initialize screen (if we're using one)
306 push es ; Save ES -> PXE entry structure
310 pop es ; Restore ES -> PXE entry structure
312 ; Tell the user we got this far
314 mov si,syslinux_banner
321 ; Assume API version 2.1, in case we find the !PXE structure without
322 ; finding the PXENV+ structure. This should really look at the Base
323 ; Code ROM ID structure in have_pxe, but this is adequate for now --
324 ; if we have !PXE, we have to be 2.1 or higher, and we don't care
325 ; about higher versions than that.
327 mov word [APIVer],0201h
330 ; Now we need to find the !PXE structure. It's *supposed* to be pointed
331 ; to by SS:[SP+4], but support INT 1Ah, AX=5650h method as well.
332 ; FIX: ES:BX should point to the PXENV+ structure on entry as well.
333 ; We should make that the second test, and not trash ES:BX...
335 cmp dword [es:bx], '!PXE'
338 ; Uh-oh, not there... try plan B
340 %if USE_PXE_PROVIDED_STACK == 0
343 int 1Ah ; May trash regs
344 %if USE_PXE_PROVIDED_STACK == 0
352 ; Okay, that gave us the PXENV+ structure, find !PXE
353 ; structure from that (if available)
354 cmp dword [es:bx], 'PXEN'
356 cmp word [es:bx+4], 'V+'
359 ; Nothing there either. Last-ditch: scan memory
360 call memory_scan_for_pxe_struct ; !PXE scan
362 call memory_scan_for_pxenv_struct ; PXENV+ scan
365 no_pxe: mov si,err_nopxe
383 cmp ax,0201h ; API version 2.1 or higher
387 les bx,[es:bx+28h] ; !PXE structure pointer
388 cmp dword [es:bx],'!PXE'
391 ; Nope, !PXE structure missing despite API 2.1+, or at least
392 ; the pointer is missing. Do a last-ditch attempt to find it.
393 call memory_scan_for_pxe_struct
396 ; Otherwise, no dice, use PXENV+ structure
400 old_api: ; Need to use a PXENV+ structure
401 mov si,using_pxenv_msg
404 mov eax,[es:bx+0Ah] ; PXE RM API
412 mov si,undi_data_len_msg
422 mov si,undi_code_len_msg
428 ; Compute base memory size from PXENV+ structure
430 movzx eax,word [es:bx+20h] ; UNDI data seg
431 cmp ax,[es:bx+24h] ; UNDI code seg
441 shr eax,10 ; Convert to kilobytes
444 mov si,pxenventry_msg
446 mov ax,[PXENVEntry+2]
467 mov si,undi_data_len_msg
477 mov si,undi_code_len_msg
483 ; Compute base memory size from !PXE structure
510 pop es ; Restore CS == DS == ES
513 ; Network-specific initialization
516 mov [LocalDomain],al ; No LocalDomain received
519 ; The DHCP client identifiers are best gotten from the DHCPREQUEST
520 ; packet (query info 1).
524 call pxe_get_cached_info
527 ; We don't use flags from the request packet, so
528 ; this is a good time to initialize DHCPMagic...
529 ; Initialize it to 1 meaning we will accept options found;
530 ; in earlier versions of PXELINUX bit 0 was used to indicate
531 ; we have found option 208 with the appropriate magic number;
532 ; we no longer require that, but MAY want to re-introduce
533 ; it in the future for vendor encapsulated options.
534 mov byte [DHCPMagic],1
537 ; Now attempt to get the BOOTP/DHCP packet that brought us life (and an IP
538 ; address). This lives in the DHCPACK packet (query info 2).
542 call pxe_get_cached_info
543 call parse_dhcp ; Parse DHCP packet
545 ; Save away MAC address (assume this is in query info 2. If this
546 ; turns out to be problematic it might be better getting it from
547 ; the query info 1 packet.)
550 movzx cx,byte [trackbuf+bootp.hardlen]
553 xor cx,cx ; Bad hardware address length
556 mov al,[trackbuf+bootp.hardware]
558 mov si,trackbuf+bootp.macaddr
562 ; Enable this if we really need to zero-pad this field...
563 ; mov cx,MAC+MAC_MAX+1
569 ; Now, get the boot file and other info. This lives in the CACHED_REPLY
570 ; packet (query info 3).
573 call pxe_get_cached_info
574 call parse_dhcp ; Parse DHCP packet
577 ; Generate the bootif string, and the hardware-based config string.
582 mov cx,bootif_str_len
585 movzx cx,byte [MACLen]
590 mov cl,1 ; CH == 0 already
596 mov [di-1],cl ; Null-terminate and strip final dash
598 ; Generate ip= option
608 call gendotquad ; This takes network byte order input
610 xchg ah,al ; Convert to host byte order
611 ror eax,16 ; (BSWAP doesn't work on 386)
628 ; Check to see if we got any PXELINUX-specific DHCP options; in particular,
629 ; if we didn't get the magic enable, do not recognize any other options.
632 test byte [DHCPMagic], 1 ; If we didn't get the magic enable...
634 mov byte [DHCPMagic], 0 ; If not, kill all other options
639 ; Initialize UDP stack
643 mov [pxe_udp_open_pkt.sip],eax
644 mov di,pxe_udp_open_pkt
645 mov bx,PXENV_UDP_OPEN
648 cmp word [pxe_udp_open_pkt.status], byte 0
650 .failed: mov si,err_udpinit
656 ; Common initialization code
658 %include "cpuinit.inc"
661 ; Now we're all set to start with our *real* business. First load the
662 ; configuration file (if any) and parse it.
664 ; In previous versions I avoided using 32-bit registers because of a
665 ; rumour some BIOSes clobbered the upper half of 32-bit registers at
666 ; random. I figure, though, that if there are any of those still left
667 ; they probably won't be trying to install Linux on them...
669 ; The code is still ripe with 16-bitisms, though. Not worth the hassle
670 ; to take'm out. In fact, we may want to put them back if we're going
671 ; to boot ELKS at some point.
675 ; Store standard filename prefix
677 prefix: test byte [DHCPMagic], 04h ; Did we get a path prefix option
686 lea si,[di-2] ; Skip final null!
689 cmp al,'.' ; Count . or - as alphanum
701 .alnum: loop .find_alnum
703 .notalnum: mov byte [si+2],0 ; Zero-terminate after delimiter
706 mov si,tftpprefix_msg
713 ; Load configuration file
718 ; Begin looking for configuration file
721 test byte [DHCPMagic], 02h
724 ; We got a DHCP option, try it first
734 ; Have to guess config file name...
736 ; Try loading by UUID.
737 cmp byte [HaveUUID],0
752 mov [di-1],cl ; Remove last dash and zero-terminate
758 ; Try loading by MAC address
766 ; Nope, try hexadecimal IP prefixes...
770 call uchexbytes ; Convert to hex string
772 mov cx,8 ; Up to 8 attempts
774 mov byte [di],0 ; Zero-terminate string
777 dec di ; Drop one character
780 ; Final attempt: "default" string
781 mov si,default_str ; "default" string
799 mov di,KernelName ; Borrow this buffer for mangled name
809 ; Linux kernel loading code is common. However, we need to define
810 ; a couple of helper macros...
813 ; Handle "ipappend" option
814 %define HAVE_SPECIAL_APPEND
815 %macro SPECIAL_APPEND 0
816 test byte [IPAppend],01h ; ip=
824 test byte [IPAppend],02h
828 mov byte [es:di-1],' ' ; Replace null with space
833 %define HAVE_UNLOAD_PREP
839 ; Now we have the config file open. Parse the config file and
840 ; run the user interface.
845 ; Boot to the local disk by returning the appropriate PXE magic.
846 ; AX contains the appropriate return code.
851 mov [LocalBootType],ax
855 ; Restore the environment we were called with
862 mov ax,[cs:LocalBootType]
867 ; kaboom: write a message and bail out. Wait for quite a while,
868 ; or a user keypress, then do a hard reboot.
871 RESET_STACK_AND_SEGS AX
872 .patch: mov si,bailmsg
873 call writestr ; Returns with AL = 0
874 .drain: call pollchar
881 and al,09h ; Magic+Timeout
889 .wait2: mov dx,[BIOS_timer]
890 .wait3: call pollchar
901 mov word [BIOS_magic],0 ; Cold reboot
902 jmp 0F000h:0FFF0h ; Reset vector address
905 ; memory_scan_for_pxe_struct:
907 ; If none of the standard methods find the !PXE structure, look for it
908 ; by scanning memory.
911 ; CF = 0, ES:BX -> !PXE structure
912 ; Otherwise CF = 1, all registers saved
914 memory_scan_for_pxe_struct:
921 mov ax,[BIOS_fbm] ; Starting segment
922 shl ax,(10-4) ; Kilobytes -> paragraphs
923 ; mov ax,01000h ; Start to look here
924 dec ax ; To skip inc ax
927 cmp ax,0A000h ; End of memory
936 movzx cx,byte [es:4] ; Length of structure
937 cmp cl,08h ; Minimum length
946 jnz .mismatch ; Checksum must == 0
949 mov [bp+8],bx ; Save BX into stack frame (will be == 0)
957 .not_found: mov si,notfound_msg
965 ; memory_scan_for_pxenv_struct:
967 ; If none of the standard methods find the PXENV+ structure, look for it
968 ; by scanning memory.
971 ; CF = 0, ES:BX -> PXENV+ structure
972 ; Otherwise CF = 1, all registers saved
974 memory_scan_for_pxenv_struct:
976 mov si,trymempxenv_msg
978 ; mov ax,[BIOS_fbm] ; Starting segment
979 ; shl ax,(10-4) ; Kilobytes -> paragraphs
980 mov ax,01000h ; Start to look here
981 dec ax ; To skip inc ax
984 cmp ax,0A000h ; End of memory
993 movzx cx,byte [es:8] ; Length of structure
994 cmp cl,26h ; Minimum length
1002 jnz .mismatch ; Checksum must == 0
1004 mov [bp+8],bx ; Save BX into stack frame
1010 .not_found: mov si,notfound_msg
1018 ; Deallocates a file structure (pointer in SI)
1021 ; XXX: We should check to see if this file is still open on the server
1022 ; side and send a courtesy ERROR packet to the server.
1027 mov word [si],0 ; Not in use
1033 ; Open a TFTP connection to the server
1036 ; DS:DI = mangled filename
1039 ; SI = socket pointer
1040 ; DX:AX = file length in bytes
1055 call allocate_socket
1058 mov ax,PKT_RETRY ; Retry counter
1059 mov word [PktTimeout],PKT_TIMEOUT ; Initial timeout
1061 .sendreq: push ax ; [bp-2] - Retry counter
1062 push si ; [bp-4] - File name
1065 mov [pxe_udp_write_pkt.buffer],di
1067 mov ax,TFTP_RRQ ; TFTP opcode
1070 lodsd ; EAX <- server override (if any)
1072 jnz .noprefix ; No prefix, and we have the server
1074 push si ; Add common prefix
1080 mov eax,[ServerIP] ; Get default server
1083 call strcpy ; Filename
1085 mov [bx+tftp_remoteip],eax
1087 push bx ; [bp-6] - TFTP block
1089 push bx ; [bp-8] - TID (local port no)
1091 mov [pxe_udp_write_pkt.status],byte 0
1092 mov [pxe_udp_write_pkt.sip],eax
1093 ; Now figure out the gateway
1099 mov [pxe_udp_write_pkt.gip],eax
1100 mov [pxe_udp_write_pkt.lport],bx
1102 mov [pxe_udp_write_pkt.rport],ax
1104 mov cx,tftp_tail_len
1106 sub di,packet_buf ; Get packet size
1107 mov [pxe_udp_write_pkt.buffersize],di
1109 mov di,pxe_udp_write_pkt
1110 mov bx,PXENV_UDP_WRITE
1113 cmp word [pxe_udp_write_pkt.status],byte 0
1117 ; Danger, Will Robinson! We need to support timeout
1118 ; and retry lest we just lost a packet...
1121 ; Packet transmitted OK, now we need to receive
1122 .getpacket: push word [PktTimeout] ; [bp-10]
1123 push word [BIOS_timer] ; [bp-12]
1125 .pkt_loop: mov bx,[bp-8] ; TID
1127 mov word [pxe_udp_read_pkt.status],0
1128 mov [pxe_udp_read_pkt.buffer],di
1129 mov [pxe_udp_read_pkt.buffer+2],ds
1130 mov word [pxe_udp_read_pkt.buffersize],packet_buf_size
1132 mov [pxe_udp_read_pkt.dip],eax
1133 mov [pxe_udp_read_pkt.lport],bx
1134 mov di,pxe_udp_read_pkt
1135 mov bx,PXENV_UDP_READ
1138 jz .got_packet ; Wait for packet
1144 dec word [bp-10] ; Timeout
1146 pop ax ; Adjust stack
1148 shl word [PktTimeout],1 ; Exponential backoff
1152 mov si,[bp-6] ; TFTP pointer
1155 mov eax,[si+tftp_remoteip]
1156 cmp [pxe_udp_read_pkt.sip],eax ; This is technically not to the TFTP spec?
1159 ; Got packet - reset timeout
1160 mov word [PktTimeout],PKT_TIMEOUT
1162 pop ax ; Adjust stack
1165 mov ax,[pxe_udp_read_pkt.rport]
1166 mov [si+tftp_remoteport],ax
1168 ; filesize <- -1 == unknown
1169 mov dword [si+tftp_filesize], -1
1170 ; Default blksize unless blksize option negotiated
1171 mov word [si+tftp_blksize], TFTP_BLOCKSIZE
1173 mov cx,[pxe_udp_read_pkt.buffersize]
1174 sub cx,2 ; CX <- bytes after opcode
1175 jb .failure ; Garbled reply
1181 je .bailnow ; ERROR reply: don't try again
1186 ; Now we need to parse the OACK packet to get the transfer
1187 ; size. SI -> first byte of options; CX -> byte count
1189 jcxz .no_tsize ; No options acked
1193 .opt_name_loop: lodsb
1196 or al,20h ; Convert to lowercase
1199 ; We ran out, and no final null
1201 .got_opt_name: ; si -> option value
1202 dec cx ; bytes left in pkt
1203 jz .err_reply ; Option w/o value
1205 ; Parse option pointed to by bx; guaranteed to be
1209 mov si,bx ; -> option name
1210 mov bx,tftp_opt_table
1215 mov di,[bx] ; Option pointer
1216 mov cx,[bx+2] ; Option len
1220 je .get_value ; OK, known option
1226 jmp .err_reply ; Non-negotiated option returned
1228 .get_value: pop si ; si -> option value
1229 pop cx ; cx -> bytes left in pkt
1230 mov bx,[bx+4] ; Pointer to data target
1231 add bx,[bp-6] ; TFTP socket pointer
1239 ja .err_reply ; Not a decimal digit
1244 ; Ran out before final null, accept anyway
1249 jnz .get_opt_name ; Not end of packet
1256 pop si ; We want the packet ptr in SI
1258 mov eax,[si+tftp_filesize]
1262 shr edx,16 ; DX:AX == EAX
1264 and eax,eax ; Set ZF depending on file size
1266 pop bp ; Junk (retry counter)
1267 jz .error_si ; ZF = 1 need to free the socket
1276 .err_reply: ; Option negotiation error. Send ERROR reply.
1277 ; ServerIP and gateway are already programmed in
1279 mov ax,[si+tftp_remoteport]
1280 mov word [pxe_udp_write_pkt.rport],ax
1281 mov word [pxe_udp_write_pkt.buffer],tftp_opt_err
1282 mov word [pxe_udp_write_pkt.buffersize],tftp_opt_err_len
1283 mov di,pxe_udp_write_pkt
1284 mov bx,PXENV_UDP_WRITE
1287 ; Write an error message and explode
1292 .bailnow: mov word [bp-2],1 ; Immediate error - no retry
1294 .failure: pop bx ; Junk
1298 dec ax ; Retry counter
1299 jnz .sendreq ; Try again
1301 .error: mov si,bx ; Socket pointer
1302 .error_si: ; Socket pointer already in SI
1303 call free_socket ; ZF <- 1, SI <- 0
1307 ; allocate_socket: Allocate a local UDP port structure
1311 ; BX = socket pointer
1319 .check: cmp word [bx], byte 0
1321 add bx,open_file_t_size
1326 ; Allocate a socket number. Socket numbers are made
1327 ; guaranteed unique by including the socket slot number
1328 ; (inverted, because we use the loop counter cx); add a
1329 ; counter value to keep the numbers from being likely to
1330 ; get immediately reused.
1332 ; The NextSocket variable also contains the top two bits
1333 ; set. This generates a value in the range 49152 to
1340 and ax,((1 << (13-MAX_OPEN_LG2))-1) | 0xC000
1342 shl cx,13-MAX_OPEN_LG2
1344 xchg ch,cl ; Convert to network byte order
1345 mov [bx],cx ; Socket in use
1351 ; Free socket: socket in SI; return SI = 0, ZF = 1 for convenience
1359 mov cx,tftp_pktbuf >> 1 ; tftp_pktbuf is not cleared
1368 ; Read a dot-quad pathname in DS:SI and output an IP
1369 ; address in EAX, with SI pointing to the first
1370 ; nonmatching character.
1372 ; Return CF=1 on error.
1374 ; No segment assumptions permitted.
1388 aad ; AL += 10 * AH; AH = 0;
1403 loop .realerror ; If CX := 1 then we're done
1409 dec si ; CF unchanged!
1413 ; mangle_name: Mangle a filename pointed to by DS:SI into a buffer pointed
1414 ; to by ES:DI; ends on encountering any whitespace.
1417 ; This verifies that a filename is < FILENAME_MAX characters
1418 ; and doesn't contain whitespace, and zero-pads the output buffer,
1419 ; so "repe cmpsb" can do a compare.
1421 ; The first four bytes of the manged name is the IP address of
1422 ; the download host.
1424 ; No segment assumptions permitted.
1429 mov eax,[cs:ServerIP]
1431 je .noip ; Null filename?!?!
1432 cmp word [si],'::' ; Leading ::?
1442 ; We have a :: prefix of some sort, it could be either
1443 ; a DNS name or a dot-quad IP address. Try the dot-quad
1467 pop cx ; Adjust stack
1468 inc si ; Skip double colon
1472 stosd ; Save IP address prefix
1473 mov cx,FILENAME_MAX-5
1477 cmp al,' ' ; If control or space, end
1482 inc cx ; At least one null byte
1483 xor ax,ax ; Zero-fill name
1484 rep stosb ; Doesn't do anything if CX=0
1489 ; unmangle_name: Does the opposite of mangle_name; converts a DOS-mangled
1490 ; filename to the conventional representation. This is needed
1491 ; for the BOOT_IMAGE= parameter for the kernel.
1493 ; NOTE: The output buffer needs to be able to hold an
1494 ; expanded IP address.
1496 ; DS:SI -> input mangled file name
1497 ; ES:DI -> output buffer
1499 ; On return, DI points to the first byte after the output name,
1500 ; which is set to a null byte.
1512 dec di ; Point to final null byte
1519 ; This is the main PXENV+/!PXE entry point, using the PXENV+
1520 ; calling convention. This is a separate local routine so
1521 ; we can hook special things from it if necessary. In particular,
1522 ; some PXE stacks seem to not like being invoked from anything but
1523 ; the initial stack, so humour it.
1527 %if USE_PXE_PROVIDED_STACK == 0
1528 mov [cs:PXEStack],sp
1529 mov [cs:PXEStack+2],ss
1530 lss sp,[cs:InitStack]
1532 .jump: call 0:pxe_thunk ; Default to calling the thunk
1533 %if USE_PXE_PROVIDED_STACK == 0
1534 lss sp,[cs:PXEStack]
1536 cld ; Make sure DF <- 0
1539 ; Must be after function def due to NASM bug
1540 PXENVEntry equ pxenv.jump+1
1545 ; Convert from the PXENV+ calling convention (BX, ES, DI) to the !PXE
1546 ; calling convention (using the stack.)
1548 ; This is called as a far routine so that we can just stick it into
1549 ; the PXENVEntry variable.
1557 cmc ; Set CF unless ax == 0
1560 ; Must be after function def due to NASM bug
1561 PXEEntry equ pxe_thunk.jump+1
1564 ; getfssec: Get multiple clusters from a file, given the starting cluster.
1566 ; In this case, get multiple blocks from a specific TCP connection.
1570 ; SI -> TFTP socket pointer
1571 ; CX -> 512-byte block count; 0FFFFh = until end of file
1573 ; SI -> TFTP socket pointer (or 0 on EOF)
1584 shl ecx,TFTP_BLOCKSIZE_LG2 ; Convert to bytes
1585 jz .hit_eof ; Nothing to do?
1590 movzx eax,word [bx+tftp_bytesleft]
1594 jcxz .need_packet ; No bytes available?
1597 mov ax,cx ; EAX<31:16> == ECX<31:16> == 0
1598 mov si,[bx+tftp_dataptr]
1599 sub [bx+tftp_bytesleft],cx
1600 fs rep movsb ; Copy from packet buffer
1601 mov [bx+tftp_dataptr],si
1612 ; Is there anything left of this?
1613 mov eax,[si+tftp_filesize]
1614 sub eax,[si+tftp_filepos]
1615 jnz .bytes_left ; CF <- 0
1617 cmp [si+tftp_bytesleft],ax
1618 jnz .bytes_left ; CF <- 0
1620 ; The socket is closed and the buffer drained
1621 ; Close socket structure and re-init for next user
1628 ; No data in buffer, check to see if we can get a packet...
1632 mov eax,[bx+tftp_filesize]
1633 cmp eax,[bx+tftp_filepos]
1634 je .hit_eof ; Already EOF'd; socket already closed
1646 ; Get a fresh packet; expects fs -> pktbuf_seg and ds:si -> socket structure
1653 ; Start by ACKing the previous packet; this should cause the
1654 ; next packet to be sent.
1656 mov word [PktTimeout],PKT_TIMEOUT
1658 .send_ack: push cx ; <D> Retry count
1660 mov ax,[si+tftp_lastpkt]
1661 call ack_packet ; Send ACK
1663 ; We used to test the error code here, but sometimes
1664 ; PXE would return negative status even though we really
1665 ; did send the ACK. Now, just treat a failed send as
1666 ; a normally lost packet, and let it time out in due
1669 .send_ok: ; Now wait for packet.
1670 mov dx,[BIOS_timer] ; Get current time
1673 .wait_data: push cx ; <E> Timeout
1674 push dx ; <F> Old time
1676 mov bx,[si+tftp_pktbuf]
1677 mov [pxe_udp_read_pkt.buffer],bx
1678 mov [pxe_udp_read_pkt.buffer+2],fs
1679 mov [pxe_udp_read_pkt.buffersize],word PKTBUF_SIZE
1680 mov eax,[si+tftp_remoteip]
1681 mov [pxe_udp_read_pkt.sip],eax
1683 mov [pxe_udp_read_pkt.dip],eax
1684 mov ax,[si+tftp_remoteport]
1685 mov [pxe_udp_read_pkt.rport],ax
1686 mov ax,[si+tftp_localport]
1687 mov [pxe_udp_read_pkt.lport],ax
1688 mov di,pxe_udp_read_pkt
1689 mov bx,PXENV_UDP_READ
1696 ; No packet, or receive failure
1698 pop ax ; <F> Old time
1699 pop cx ; <E> Timeout
1700 cmp ax,dx ; Same time -> don't advance timeout
1701 je .wait_data ; Same clock tick
1702 loop .wait_data ; Decrease timeout
1704 pop cx ; <D> Didn't get any, send another ACK
1705 shl word [PktTimeout],1 ; Exponential backoff
1707 jmp kaboom ; Forget it...
1709 .recv_ok: pop dx ; <F>
1712 cmp word [pxe_udp_read_pkt.buffersize],byte 4
1713 jb .wait_data ; Bad size for a DATA packet
1715 mov bx,[si+tftp_pktbuf]
1716 cmp word [fs:bx],TFTP_DATA ; Not a data packet?
1717 jne .wait_data ; Then wait for something else
1719 mov ax,[si+tftp_lastpkt]
1720 xchg ah,al ; Host byte order
1721 inc ax ; Which packet are we waiting for?
1722 xchg ah,al ; Network byte order
1726 ; Wrong packet, ACK the packet and then try again
1727 ; This is presumably because the ACK got lost,
1728 ; so the server just resent the previous packet
1731 jmp .send_ok ; Reset timeout
1733 .right_packet: ; It's the packet we want. We're also EOF if the size < blocksize
1735 pop cx ; <D> Don't need the retry count anymore
1737 mov [si+tftp_lastpkt],ax ; Update last packet number
1739 movzx ecx,word [pxe_udp_read_pkt.buffersize]
1740 sub cx,byte 4 ; Skip TFTP header
1742 ; If this is a zero-length block, don't mess with the pointers,
1743 ; since we may have just set up the previous block that way
1746 ; Set pointer to data block
1747 lea ax,[bx+4] ; Data past TFTP header
1748 mov [si+tftp_dataptr],ax
1750 add [si+tftp_filepos],ecx
1751 mov [si+tftp_bytesleft],cx
1753 cmp cx,[si+tftp_blksize] ; Is it a full block?
1754 jb .last_block ; If so, it's not EOF
1756 ; If we had the exact right number of bytes, always get
1757 ; one more packet to get the (zero-byte) EOF packet and
1759 mov eax,[si+tftp_filepos]
1760 cmp [si+tftp_filesize],eax
1766 .last_block: ; Last block - ACK packet immediately
1770 ; Make sure we know we are at end of file
1771 mov eax,[si+tftp_filepos]
1772 mov [si+tftp_filesize],eax
1779 ; Send ACK packet. This is a common operation and so is worth canning.
1783 ; AX = Packet # to ack (network byte order)
1786 ; All registers preserved
1788 ; This function uses the pxe_udp_write_pkt but not the packet_buf.
1792 mov [ack_packet_buf+2],ax ; Packet number to ack
1794 mov [pxe_udp_write_pkt.lport],ax
1795 mov ax,[si+tftp_remoteport]
1796 mov [pxe_udp_write_pkt.rport],ax
1797 mov eax,[si+tftp_remoteip]
1798 mov [pxe_udp_write_pkt.sip],eax
1804 mov [pxe_udp_write_pkt.gip],eax
1805 mov [pxe_udp_write_pkt.buffer],word ack_packet_buf
1806 mov [pxe_udp_write_pkt.buffersize], word 4
1807 mov di,pxe_udp_write_pkt
1808 mov bx,PXENV_UDP_WRITE
1810 cmp ax,byte 0 ; ZF = 1 if write OK
1817 ; This function unloads the PXE and UNDI stacks and unclaims
1821 test byte [KeepPXE],01h ; Should we keep PXE around?
1831 mov si,new_api_unload
1832 cmp byte [APIVer+1],2 ; Major API version >= 2?
1834 mov si,old_api_unload
1837 .call_loop: xor ax,ax
1842 mov di,pxe_unload_stack_pkt
1845 mov cx,pxe_unload_stack_pkt_len >> 1
1850 mov ax,word [pxe_unload_stack_pkt.status]
1851 cmp ax,PXENV_STATUS_SUCCESS
1858 mov dx,[RealBaseMem]
1859 cmp dx,[BIOS_fbm] ; Sanity check
1863 ; Check that PXE actually unhooked the INT 1Ah chain
1864 movzx eax,word [4*0x1a]
1865 movzx ecx,word [4*0x1a+2]
1869 cmp ax,dx ; Not in range
1883 mov si,cant_free_msg
1899 ; We want to keep PXE around, but still we should reset
1900 ; it to the standard bootup configuration
1905 mov bx,PXENV_UDP_CLOSE
1906 mov di,pxe_udp_close_pkt
1914 ; Take an IP address (in network byte order) in EAX and
1915 ; output a dotted quad string to ES:DI.
1916 ; DI points to terminal null at end of string on exit.
1925 jb .lt10 ; If so, skip first 2 digits
1928 jb .lt100 ; If so, skip first digit
1931 ; Now AH = 100-digit; AL = remainder
1938 ; Now AH = 10-digit; AL = remainder
1949 ror eax,8 ; Move next char into LSB
1957 ; uchexbytes/lchexbytes
1959 ; Take a number of bytes in memory and convert to upper/lower-case
1963 ; DS:SI = input bytes
1964 ; ES:DI = output buffer
1965 ; CX = number of bytes
1967 ; DS:SI = first byte after
1968 ; ES:DI = first byte after
2000 ; pxe_get_cached_info
2002 ; Get a DHCP packet from the PXE stack into the trackbuf.
2009 ; Assumes CS == DS == ES.
2011 pxe_get_cached_info:
2013 mov di,pxe_bootp_query_pkt
2022 stosw ; Buffer offset
2024 stosw ; Buffer segment
2026 pop di ; DI -> parameter set
2027 mov bx,PXENV_GET_CACHED_INFO
2034 mov cx,[pxe_bootp_query_pkt.buffersize]
2038 mov si,err_pxefailed
2044 ; Parse a DHCP packet. This includes dealing with "overloaded"
2045 ; option fields (see RFC 2132, section 9.3)
2047 ; This should fill in the following global variables, if the
2048 ; information is present:
2050 ; MyIP - client IP address
2051 ; ServerIP - boot server IP address
2052 ; Netmask - network mask
2053 ; Gateway - default gateway router IP
2054 ; BootFile - boot file name
2055 ; DNSServers - DNS server IPs
2056 ; LocalDomain - Local domain name
2057 ; MACLen, MAC - Client identifier, if MACLen == 0
2059 ; This assumes the DHCP packet is in "trackbuf" and the length
2060 ; of the packet in in CX on entry.
2064 mov byte [OverLoad],0 ; Assume no overload
2065 mov eax, [trackbuf+bootp.yip]
2068 cmp al,224 ; Class D or higher -> bad
2072 mov eax, [trackbuf+bootp.sip]
2075 cmp al,224 ; Class D or higher -> bad
2079 sub cx, bootp.options
2081 mov si, trackbuf+bootp.option_magic
2083 cmp eax, BOOTP_OPTION_MAGIC
2085 call parse_dhcp_options
2087 mov si, trackbuf+bootp.bootfile
2088 test byte [OverLoad],1
2091 call parse_dhcp_options
2092 jmp short .parsed_file
2095 jz .parsed_file ; No bootfile name
2100 stosb ; Null-terminate
2102 mov si, trackbuf+bootp.sname
2103 test byte [OverLoad],2
2106 call parse_dhcp_options
2111 ; Parse a sequence of DHCP options, pointed to by DS:SI; the field
2112 ; size is CX -- some DHCP servers leave option fields unterminated
2113 ; in violation of the spec.
2115 ; For parse_some_dhcp_options, DH contains the minimum value for
2116 ; the option to recognize -- this is used to restrict parsing to
2117 ; PXELINUX-specific options only.
2122 parse_some_dhcp_options:
2129 jz .done ; Last byte; must be PAD, END or malformed
2130 cmp al, 0 ; PAD option
2132 cmp al,255 ; END option
2135 ; Anything else will have a length field
2136 mov dl,al ; DL <- option number
2138 lodsb ; AX <- option length
2140 sub cx,ax ; Decrement bytes left counter
2141 jb .done ; Malformed option: length > field size
2143 cmp dl,dh ; Is the option value valid?
2146 mov bx,dhcp_option_list
2148 cmp bx,dhcp_option_list_end
2160 ; Unknown option. Skip to the next one.
2180 ; Parse individual DHCP options. SI points to the option data and
2181 ; AX to the option length. DL contains the option number.
2182 ; All registers are saved around the routine.
2197 cmp cl,DNS_MAX_SERVERS
2199 mov cl,DNS_MAX_SERVERS
2203 mov [LastDNSServer],di
2206 dopt 16, local_domain
2210 xchg [bx],al ; Zero-terminate option
2212 call dns_mangle ; Convert to DNS label set
2213 mov [bx],al ; Restore ending byte
2216 dopt 43, vendor_encaps
2217 mov dh,208 ; Only recognize PXELINUX options
2218 mov cx,ax ; Length of option = max bytes to parse
2219 call parse_some_dhcp_options ; Parse recursive structure
2222 dopt 52, option_overload
2229 cmp dword [ServerIP],0
2230 jne .skip ; Already have a next server IP
2231 cmp al,224 ; Class D or higher
2236 dopt 61, client_identifier
2237 cmp ax,MAC_MAX ; Too long?
2239 cmp ax,2 ; Too short?
2241 cmp [MACLen],ah ; Only do this if MACLen == 0
2244 lodsb ; Client identifier type
2247 jne .skip ; Client identifier is not a MAC
2254 dopt 67, bootfile_name
2258 dopt 97, uuid_client_identifier
2259 cmp ax,17 ; type byte + 16 bytes UUID
2261 mov dl,[si] ; Must have type 0 == UUID
2262 or dl,[HaveUUID] ; Capture only the first instance
2264 mov byte [HaveUUID],1 ; Got UUID
2269 dopt 209, pxelinux_configfile
2271 or byte [DHCPMagic],2 ; Got config file
2274 dopt 210, pxelinux_pathprefix
2276 or byte [DHCPMagic],4 ; Got path prefix
2279 dopt 211, pxelinux_reboottime
2283 xchg bl,bh ; Convert to host byte order
2286 mov [RebootTime],ebx
2287 or byte [DHCPMagic],8 ; Got RebootTime
2290 ; Common code for copying an option verbatim
2291 ; Copies the option into ES:DI and null-terminates it.
2292 ; Returns with AX=0 and SI past the option.
2294 xchg cx,ax ; CX <- option length
2296 xchg cx,ax ; AX <- 0
2297 stosb ; Null-terminate
2301 dhcp_option_list_end:
2306 uuid_dashes db 4,2,2,2,6,0 ; Bytes per UUID dashed section
2312 ; Generate an ip=<client-ip>:<boot-server-ip>:<gw-ip>:<netmask>
2313 ; option into IPOption based on a DHCP packet in trackbuf.
2314 ; Assumes CS == DS == ES.
2335 call gendotquad ; Zero-terminates its output
2337 mov [IPOptionLen],di
2342 ; Call the receive loop while idle. This is done mostly so we can respond to
2343 ; ARP messages, but perhaps in the future this can be used to do network
2346 ; hpa sez: people using automatic control on the serial port get very
2347 ; unhappy if we poll for ARP too often (the PXE stack is pretty slow,
2348 ; typically.) Therefore, only poll if at least 4 BIOS timer ticks have
2349 ; passed since the last poll, and reset this when a character is
2350 ; received (RESET_IDLE).
2356 mov ax,[cs:BIOS_timer]
2357 mov [cs:IdleTimer],ax
2363 mov ax,[cs:BIOS_timer]
2364 sub ax,[cs:IdleTimer]
2376 mov [pxe_udp_read_pkt.status],al ; 0
2377 mov [pxe_udp_read_pkt.buffer],di
2378 mov [pxe_udp_read_pkt.buffer+2],ds
2379 mov word [pxe_udp_read_pkt.buffersize],packet_buf_size
2381 mov [pxe_udp_read_pkt.dip],eax
2382 mov word [pxe_udp_read_pkt.lport],htons(9) ; discard port
2383 mov di,pxe_udp_read_pkt
2384 mov bx,PXENV_UDP_READ
2395 ; -----------------------------------------------------------------------------
2397 ; -----------------------------------------------------------------------------
2399 %include "getc.inc" ; getc et al
2400 %include "conio.inc" ; Console I/O
2401 %include "writestr.inc" ; String output
2402 writestr equ cwritestr
2403 %include "writehex.inc" ; Hexadecimal output
2404 %include "configinit.inc" ; Initialize configuration
2405 %include "parseconfig.inc" ; High-level config file handling
2406 %include "parsecmd.inc" ; Low-level config file handling
2407 %include "bcopy32.inc" ; 32-bit bcopy
2408 %include "loadhigh.inc" ; Load a file into high memory
2409 %include "font.inc" ; VGA font stuff
2410 %include "graphics.inc" ; VGA graphics
2411 %include "highmem.inc" ; High memory sizing
2412 %include "strcpy.inc" ; strcpy()
2413 %include "rawcon.inc" ; Console I/O w/o using the console functions
2414 %include "dnsresolv.inc" ; DNS resolver
2415 %include "adv.inc" ; Auxillary Data Vector
2417 ; -----------------------------------------------------------------------------
2418 ; Begin data section
2419 ; -----------------------------------------------------------------------------
2423 copyright_str db ' Copyright (C) 1994-', year, ' H. Peter Anvin'
2425 err_bootfailed db CR, LF, 'Boot failed: press a key to retry, or wait for reset...', CR, LF, 0
2426 bailmsg equ err_bootfailed
2427 err_nopxe db "No !PXE or PXENV+ API found; we're dead...", CR, LF, 0
2428 err_pxefailed db 'PXE API call failed, error ', 0
2429 err_udpinit db 'Failed to initialize UDP stack', CR, LF, 0
2430 err_noconfig db 'Unable to locate configuration file', CR, LF, 0
2431 err_oldtftp db 'TFTP server does not support the tsize option', CR, LF, 0
2432 found_pxenv db 'Found PXENV+ structure', CR, LF, 0
2433 using_pxenv_msg db 'Old PXE API detected, using PXENV+ structure', CR, LF, 0
2434 apiver_str db 'PXE API version is ',0
2435 pxeentry_msg db 'PXE entry point found (we hope) at ', 0
2436 pxenventry_msg db 'PXENV entry point found (we hope) at ', 0
2437 trymempxe_msg db 'Scanning memory for !PXE structure... ', 0
2438 trymempxenv_msg db 'Scanning memory for PXENV+ structure... ', 0
2439 undi_data_msg db 'UNDI data segment at: ',0
2440 undi_data_len_msg db 'UNDI data segment size: ',0
2441 undi_code_msg db 'UNDI code segment at: ',0
2442 undi_code_len_msg db 'UNDI code segment size: ',0
2443 cant_free_msg db 'Failed to free base memory, error ', 0
2444 notfound_msg db 'not found', CR, LF, 0
2445 myipaddr_msg db 'My IP address seems to be ',0
2446 tftpprefix_msg db 'TFTP prefix: ', 0
2447 localboot_msg db 'Booting from local disk...', CR, LF, 0
2448 trying_msg db 'Trying to load: ', 0
2449 fourbs_msg db BS, BS, BS, BS, 0
2450 default_str db 'default', 0
2451 syslinux_banner db CR, LF, 'PXELINUX ', version_str, ' ', date, ' ', 0
2452 cfgprefix db 'pxelinux.cfg/' ; No final null!
2453 cfgprefix_len equ ($-cfgprefix)
2456 ; Command line options we'd like to take a look at
2458 ; mem= and vga= are handled as normal 32-bit integer values
2459 initrd_cmd db 'initrd='
2460 initrd_cmd_len equ $-initrd_cmd
2462 ; This one we make ourselves
2463 bootif_str db 'BOOTIF='
2464 bootif_str_len equ $-bootif_str
2466 ; Config file keyword table
2468 %include "keywords.inc"
2471 ; Extensions to search for (in *forward* order).
2472 ; (.bs and .bss are disabled for PXELINUX, since they are not supported)
2475 exten_table: db '.cbt' ; COMBOOT (specific)
2476 db '.0', 0, 0 ; PXE bootstrap program
2477 db '.com' ; COMBOOT (same as DOS)
2480 dd 0, 0 ; Need 8 null bytes here
2483 ; PXE unload sequences
2487 db PXENV_UNDI_SHUTDOWN
2488 db PXENV_UNLOAD_STACK
2493 db PXENV_UNDI_SHUTDOWN
2494 db PXENV_UNLOAD_STACK
2495 db PXENV_UNDI_CLEANUP
2499 ; PXE query packets partially filled in
2502 pxe_bootp_query_pkt:
2503 .status: resw 1 ; Status
2504 .packettype: resw 1 ; Boot server packet type
2505 .buffersize: resw 1 ; Packet size
2506 .buffer: resw 2 ; seg:off of buffer
2507 .bufferlimit: resw 1 ; Unused
2511 .status: dw 0 ; Status
2512 .sip: dd 0 ; Source (our) IP
2515 .status: dw 0 ; Status
2518 .status: dw 0 ; Status
2519 .sip: dd 0 ; Server IP
2520 .gip: dd 0 ; Gateway IP
2521 .lport: dw 0 ; Local port
2522 .rport: dw 0 ; Remote port
2523 .buffersize: dw 0 ; Size of packet
2524 .buffer: dw 0, 0 ; seg:off of buffer
2527 .status: dw 0 ; Status
2528 .sip: dd 0 ; Source IP
2529 .dip: dd 0 ; Destination (our) IP
2530 .rport: dw 0 ; Remote port
2531 .lport: dw 0 ; Local port
2532 .buffersize: dw 0 ; Max packet size
2533 .buffer: dw 0, 0 ; seg:off of buffer
2536 ; Misc initialized (data) variables
2539 BaseStack dd StackBuf ; ESP of base stack
2540 dw 0 ; SS of base stack
2541 NextSocket dw 49152 ; Counter for allocating socket numbers
2542 KeepPXE db 0 ; Should PXE be kept around?
2547 tftp_tail db 'octet', 0 ; Octet mode
2548 tsize_str db 'tsize' ,0 ; Request size
2549 tsize_len equ ($-tsize_str)
2551 blksize_str db 'blksize', 0 ; Request large blocks
2552 blksize_len equ ($-blksize_str)
2553 asciidec TFTP_LARGEBLK
2555 tftp_tail_len equ ($-tftp_tail)
2559 ; Options negotiation parsing table (string pointer, string len, offset
2560 ; into socket structure)
2563 dw tsize_str, tsize_len, tftp_filesize
2564 dw blksize_str, blksize_len, tftp_blksize
2565 tftp_opts equ ($-tftp_opt_table)/6
2568 ; Error packet to return on options negotiation error
2570 tftp_opt_err dw TFTP_ERROR ; ERROR packet
2571 dw TFTP_EOPTNEG ; ERROR 8: bad options
2572 db 'tsize option required', 0 ; Error message
2573 tftp_opt_err_len equ ($-tftp_opt_err)
2576 ack_packet_buf: dw TFTP_ACK, 0 ; TFTP ACK packet
2579 ; IP information (initialized to "unknown" values)
2580 MyIP dd 0 ; My IP address
2581 ServerIP dd 0 ; IP address of boot server
2582 Netmask dd 0 ; Netmask of this subnet
2583 Gateway dd 0 ; Default router
2584 ServerPort dw TFTP_PORT ; TFTP server port
2587 ; Variables that are uninitialized in SYSLINUX but initialized here
2590 BufSafe dw trackbufsize/TFTP_BLOCKSIZE ; Clusters we can load into trackbuf
2591 BufSafeBytes dw trackbufsize ; = how many bytes?
2593 %if ( trackbufsize % TFTP_BLOCKSIZE ) != 0
2594 %error trackbufsize must be a multiple of TFTP_BLOCKSIZE