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pxechain.asm

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Revision 49029ca74eaf5d657d429d9c7c5085e5109d444a, 9.8 KB (checked in by H. Peter Anvin <hpa@…>, 3 years ago)

pxechain: remove unused ipaddrbuf

Remove unused ipaddrbuf.

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1	; "$Id: pxechain.asm,v 1.2 2007/12/16 08:15:39 jhutz Exp $"
2	; -- fundamental -- (asm-mode sucks) vim:noet:com=\:;
3	; ****************************************************************************
4	;
5	; pxechain.asm
6	;
7	; A comboot program to chain from PXELINUX to another PXE network
8	; bootstrap program (NBP). This improves on PXELINUX's built-in PXE
9	; chaining support by arranging for the server address and boot filename
10	; reported by the PXE stack to be those from which the new NBP was
11	; loaded, allowing PXELINUX to be used to select from multiple NBP's,
12	; such as gPXE, another PXELINUX(), Windows RIS, and so on.*
13	;
14	; () This seems unnecessary at first, but it is very helpful when*
15	; selecting from among self-contained network boot images.
16	;
17	; Copyright (c) 2007 Carnegie Mellon University
18	; Copyright (C) 1994-2007 H. Peter Anvin
19	;
20	; This program is free software; you can redistribute it and/or modify
21	; it under the terms of the GNU General Public License as published by
22	; the Free Software Foundation, Inc., 53 Temple Place Ste 330,
23	; Boston MA 02111-1307, USA; either version 2 of the License, or
24	; (at your option) any later version; incorporated herein by reference.
25	;
26	; ****************************************************************************
27
28	;%define DEBUG
29	;%define NO_RUN
30
31	absolute 0
32	pspInt20: resw 1
33	pspNextP: resw 1
34	resb 124
35	pspCmdLen: resb 1
36	pspCmdArg: resb 127
37
38	section .text
39	org 0x100
40
41	%ifdef DEBUG
42	%macro MARK 1.nolist
43	mov ah,0x02
44	mov dl,%1&0xff
45	int 0x21
46	%if (%1 >> 8) & 0xff
47	mov dl,(%1 >> 8) & 0xff
48	int 0x21
49	%if (%1 >> 16) & 0xff
50	mov dl,(%1 >> 16) & 0xff
51	int 0x21
52	%if (%1 >> 24) & 0xff
53	mov dl,(%1 >> 24) & 0xff
54	int 0x21
55	%endif
56	%endif
57	%endif
58	mov dl,' '
59	int 0x21
60	%endmacro
61	%macro SHOWD 1.nolist
62	mov al,%1
63	call print_dec
64	mov ah,0x02
65	mov dl,' '
66	int 0x21
67	%endmacro
68	%macro SHOWX 1.nolist
69	mov bx,%1
70	call print_hex
71	mov ah,0x02
72	mov dl,' '
73	int 0x21
74	%endmacro
75	%else
76	%macro MARK 1.nolist
77	%endmacro
78	%macro SHOWD 1.nolist
79	%endmacro
80	%macro SHOWX 1.nolist
81	%endmacro
82	%endif
83
84	_start:
85	MARK 'INIT'
86
87	; There should be exactly one command-line argument, which is of the form
88	; [[ipaddress]::]tftp_filename, just like filenames given to PXELINUX.
89	; Too few or too many arguments is an error.
90	;
91	; This code is based on mangle_name in pxelinux.asm
92	parse_args:
93	cld
94	xor cx,cx
95	mov cl,[pspCmdLen]
96	dec cx
97	mov si,pspCmdArg+1
98	and cx,cx
99	je near usage ; no args is bad
100	add si,cx
101	dec si
102	std
103	.chomp: lodsb
104	cmp al,' '
105	loopz .chomp
106	inc cx
107	cld
108	mov [pspCmdLen],cl
109	mov si,pspCmdArg+1
110	cmp word [si],'::' ; Leading ::?
111	je near gotprefix
112	dec cx
113	jz noip
114	MARK 'SCAN'
115
116	.more:
117	inc si
118	cmp byte [si],' '
119	je near usage
120	cmp word [si],'::'
121	je near parse_ip
122	loop .more
123
124	noip:
125	MARK 'NOIP'
126	mov ax,0x0e ; get config file name
127	int 0x22
128	mov si,bx
129	%ifdef DEBUG
130	mov ah,0x02
131	mov dl,'['
132	int 0x21
133	mov ax,0x02
134	int 0x22
135	mov ah,0x02
136	mov dl,']'
137	int 0x21
138	mov dl,' '
139	int 0x21
140	%endif
141	push ds
142	push es
143	pop ds
144	pop es
145	push es
146	.find_prefix:
147	lodsb
148	and al,al
149	jnz .find_prefix
150	dec si
151
152	mov cx,si
153	sub cx,bx
154	MARK 'LEN'
155	SHOWD cl ; assume it's <256 for debugging
156	dec si
157	std
158	.find_slash:
159	lodsb
160	cmp al,'/'
161	je .slash
162	loop .find_slash
163	.slash:
164	cmp cx,127
165	cld
166	jna .copy_prefix
167	pop ds
168	jmp too_long
169
170	.copy_prefix:
171	SHOWD cl
172	MARK 'PFX'
173	mov si,bx
174	mov di,tftp_filename
175	mov bx,128
176	sub bx,cx
177	rep movsb
178	pop ds
179
180	mov cl,[pspCmdLen]
181	mov si,pspCmdArg+1
182	jmp prefix_done
183
184	usage:
185	xor cx,cx
186	mov si,msg_usage
187	jmp fail
188
189	too_long:
190	xor cx,cx
191	mov si,msg_too_long
192	jmp fail
193
194	parse_ip:
195	MARK 'PIP'
196	mov di,si
197	mov si,pspCmdArg+1
198	call parse_dotquad
199	jc .notdq
200	cmp si,di ; is it the same place?
201	jne .notdq
202	mov [tftp_siaddr],eax
203	jmp gotprefix
204	.notdq:
205	MARK 'NDQ'
206	mov si,di
207	mov bx,pspCmdArg+1
208	mov ax,0x0010 ; DNS resolve
209	int 0x22
210	and eax,eax
211	jz noip
212	mov [tftp_siaddr],eax
213	gotprefix:
214	MARK 'GOTP'
215	dec cx ; skip the ::
216	dec cx
217	inc si
218	inc si
219	mov di,tftp_filename
220	mov bx,128
221
222	prefix_done:
223	SHOWD bl
224	MARK 'LEFT'
225
226	; SI points at the filename, plus remaining arguments,
227	; CX contains their combined length.
228	; DI points to where the filename should be stored
229	; BX says how much space is left for the filename and NUL
230
231	and cx,cx
232	jz usage ; no args is bad
233	.copy_filename:
234	lodsb
235	%ifdef DEBUG
236	mov dl,al
237	mov ah,0x2
238	int 0x21
239	%endif
240	cmp al,' '
241	je usage
242	dec bx
243	jz too_long
244	stosb
245	loop .copy_filename
246	xor eax,eax
247	stosb
248
249	; get PXE cached data
250	MARK 'GCI'
251	mov ax,0x0009 ; call PXE stack
252	mov bx,0x0071 ; PXENV_GET_CACHED_INFO
253	mov di,PXECacheParms
254	int 0x22
255	and eax,eax
256	jz .fix_siaddr
257	mov cx,[gci_status]
258	mov si,msg_get_cache
259	jmp fail
260
261	.fix_siaddr:
262	mov bx,[gci_bufferseg]
263	mov es,bx
264	mov bx,[gci_buffer]
265	mov eax,[es:bx+12] ; save our address (ciaddr)
266	mov [open_ciaddr],eax ; ... in case we have to do UDP open
267	mov eax,[tftp_siaddr]
268	and eax,eax
269	jnz .replace_addr
270	MARK 'ADDR'
271	mov eax,[es:bx+20] ; siaddr
272	mov [tftp_siaddr],eax
273	jmp .addr_done
274	.replace_addr:
275	mov [es:bx+20],eax
276	.addr_done:
277	mov si,tftp_filename ; copy the new filename...
278	lea di,[es:bx+108] ; to the "cached DHCP response"
279	mov cx,128
280	rep movsb
281	mov bx,ds ; restore es before proceeding
282	mov es,bx
283
284	; print out what we are doing
285	%ifdef DEBUG
286	mov ah,0x02 ; write character
287	mov dl,0x0d ; print a CRLF first
288	int 0x21
289	mov dl,0x0a
290	int 0x21
291	%endif
292	mov ax,0x0002 ; write string
293	mov bx,msg_booting
294	int 0x22
295	mov ebx,[tftp_siaddr]
296	call print_dotquad
297	mov ah,0x02 ; write character
298	mov dl,' '
299	int 0x21
300	mov ax,0x0002 ; write string
301	mov bx,tftp_filename
302	int 0x22
303	mov ah,0x02 ; write character
304	mov dl,0x0d
305	int 0x21
306	mov dl,0x0a
307	int 0x21
308
309	%ifndef NO_RUN
310	mov ax,0x0009 ; call PXE stack
311	mov bx,0x0031 ; PXENV_UDP_CLOSE
312	mov di,PXECloseParms
313	int 0x22
314	mov cx,[close_status]
315	mov si,msg_udp_close
316	and ax,ax
317	jnz fail
318
319	mov ax,0x0009 ; call PXE stack
320	mov bx,0x0073 ; PXENV_RESTART_TFTP
321	mov di,PXERestartTFTPParms
322	int 0x22
323	mov cx,[tftp_status]
324	mov si,msg_rst_tftp
325	call fail
326
327	mov ax,0x0009 ; call PXE stack
328	mov bx,0x0030 ; PXENV_UDP_OPEN
329	mov di,PXEOpenParms
330	int 0x22
331	mov cx,[open_status]
332	mov si,msg_udp_open
333	and ax,ax
334	jnz fail
335	ret
336	%endif
337
338	fail:
339	MARK 'FAIL'
340	SHOWX cs
341	SHOWX ds
342	SHOWX es
343	SHOWX si
344	%ifdef DEBUG
345	mov ah,0x02 ; write character
346	mov dl,0x0d ; print a CRLF first
347	int 0x21
348	mov dl,0x0a
349	int 0x21
350	%endif
351	mov ax,0x0002 ; write string
352	mov bx,msg_progname ; print our name
353	int 0x22
354	mov bx,si ; ... the error message
355	int 0x22
356	mov ah,0x02 ; write character
357	jcxz .done
358	mov dl,' ' ; ... and the error code, in []
359	int 0x21
360	mov dl,'['
361	int 0x21
362	mov bx,cx
363	call print_hex
364	mov ah,0x02 ; write character
365	mov dl,']'
366	int 0x21
367	.done:
368	mov dl,0x0d ; and finally a CRLF
369	int 0x21
370	mov dl,0x0a
371	int 0x21
372	ret
373
374
375	; print_hex
376	;
377	; Take a 16-bit integer in BX and print it as 2 hex digits.
378	; Destroys AX and DL.
379	;
380	print_hex:
381	mov al,bh
382	aam 16
383	cmp ah,10
384	jb .lt_a000
385	add ah,'A'-'0'-10
386	.lt_a000: add ah,'0'
387	mov dl,ah
388	mov ah,0x02 ; write character
389	int 0x21
390
391	cmp al,10
392	jb .lt_a00
393	add al,'A'-'0'-10
394	.lt_a00: add al,'0'
395	mov dl,al
396	mov ah,0x02 ; write character
397	int 0x21
398
399	mov al,bl
400	aam 16
401	cmp ah,10
402	jb .lt_a0
403	add ah,'A'-'0'-10
404	.lt_a0: add ah,'0'
405	mov dl,ah
406	mov ah,0x02 ; write character
407	int 0x21
408
409	cmp al,10
410	jb .lt_a
411	add al,'A'-'0'-10
412	.lt_a: add al,'0'
413	mov dl,al
414	mov ah,0x02 ; write character
415	int 0x21
416	ret
417
418
419	; print_dec
420	;
421	; Take an 8-bit integer in AL and print it in decimal.
422	; Destroys AX and DL.
423	;
424	print_dec:
425	cmp al,10 ; < 10?
426	jb .lt10 ; If so, skip first 2 digits
427
428	cmp al,100 ; < 100
429	jb .lt100 ; If so, skip first digit
430
431	aam 100
432	; Now AH = 100-digit; AL = remainder
433	add ah,'0'
434	mov dl,ah
435	mov ah,0x02
436	int 0x21
437
438	.lt100:
439	aam 10
440	; Now AH = 10-digit; AL = remainder
441	add ah,'0'
442	mov dl,ah
443	mov ah,0x02
444	int 0x21
445
446	.lt10:
447	add al,'0'
448	mov dl,al
449	mov ah,0x02
450	int 0x21
451	ret
452
453
454	; print_dotquad
455	;
456	; Take an IP address (in network byte order) in EBX and print it
457	; as a dotted quad.
458	; Destroys EAX, EBX, ECX, EDX
459	;
460	print_dotquad:
461	mov cx,3
462	.octet:
463	mov al,bl
464	call print_dec
465	jcxz .done
466	mov ah,0x02
467	mov dl,'.'
468	int 0x21
469	ror ebx,8 ; Move next char into LSB
470	dec cx
471	jmp .octet
472	.done:
473	ret
474
475
476	; parse_dotquad:
477	; Read a dot-quad pathname in DS:SI and output an IP
478	; address in EAX, with SI pointing to the first
479	; nonmatching character.
480	;
481	; Return CF=1 on error.
482	;
483	; No segment assumptions permitted.
484	;
485	parse_dotquad:
486	push cx
487	mov cx,4
488	xor eax,eax
489	.parseloop:
490	mov ch,ah
491	mov ah,al
492	lodsb
493	sub al,'0'
494	jb .notnumeric
495	cmp al,9
496	ja .notnumeric
497	aad ; AL += 10 AH; AH = 0;*
498	xchg ah,ch
499	jmp .parseloop
500	.notnumeric:
501	cmp al,'.'-'0'
502	pushf
503	mov al,ah
504	mov ah,ch
505	xor ch,ch
506	ror eax,8
507	popf
508	jne .error
509	loop .parseloop
510	jmp .done
511	.error:
512	loop .realerror ; If CX := 1 then we're done
513	clc
514	jmp .done
515	.realerror:
516	stc
517	.done:
518	dec si ; CF unchanged!
519	pop cx
520	ret
521
522	section .data
523	msg_booting: db 'TFTP boot: ',0
524	msg_progname: db 'pxechain: ',0
525	msg_usage: db 'usage: pxechain.cbt [[ipaddress]::]filename',0dh,0ah,0
526	msg_too_long: db 'pxechain: filename is too long (max 127)',0dh,0ah,0
527	msg_get_cache: db 'PXENV_GET_CACHED_INFO',0
528	msg_rst_tftp: db 'PXENV_RESTART_TFTP',0
529	msg_udp_close: db 'PXENV_UDP_CLOSE',0
530	msg_udp_open: db 'PXENV_UDP_OPEN',0
531
532	PXECacheParms:
533	gci_status: dw 0
534	gci_packettype: dw 3 ; PXENV_PACKET_TYPE_CACHED_REPLY
535	gci_buffersize: dw 0
536	gci_buffer: dw 0
537	gci_bufferseg: dw 0
538	gci_bufferlim: dw 0
539
540	PXERestartTFTPParms:
541	tftp_status: dw 0
542	tftp_filename: times 128 db 0
543	tftp_bufsize: dd 0x00090000 ; available memory for NBP
544	tftp_bufaddr: dd 0x00007c00 ; PXE NBP load address
545	tftp_siaddr: dd 0
546	tftp_giaddr: dd 0
547	tftp_mcaddr: dd 0
548	tftp_mcport: dw 0
549	tftp_msport: dw 0
550	tftp_timeout: dw 0
551	tftp_reopendly: dw 0
552
553	PXECloseParms:
554	close_status: dw 0
555
556	PXEOpenParms:
557	open_status: dw 0
558	open_ciaddr: dd 0

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