1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1998 Robert Nordier
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
21 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
22 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
23 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
25 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
26 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef lint
30static const char rcsid[] =
31  "$FreeBSD$";
32#endif /* not lint */
33
34#include <sys/param.h>
35#include <sys/endian.h>
36#include <sys/stat.h>
37#include <sys/mman.h>
38
39/* XXX make this work as an i386/amd64 cross-tool */
40#include <machine/exec.h>
41#undef __LDPGSZ
42#define __LDPGSZ	4096
43
44#include <netinet/in.h>
45
46#include <a.out.h>
47#include <err.h>
48#include <errno.h>
49#include <fcntl.h>
50#include <stdarg.h>
51#include <stdio.h>
52#include <stdlib.h>
53#include <string.h>
54#include <unistd.h>
55
56#include "btx.h"
57#include "elfh.h"
58
59#define BTX_PATH		"/sys/boot/i386/btx"
60
61#define I_LDR	0		/* BTX loader */
62#define I_BTX	1		/* BTX kernel */
63#define I_CLNT	2		/* Client program */
64
65#define F_BIN	0		/* Binary */
66#define F_AOUT	1		/* ZMAGIC a.out */
67#define F_ELF	2		/* 32-bit ELF */
68#define F_CNT	3		/* Number of formats */
69
70#define IMPURE	1		/* Writable text */
71#define MAXU32	0xffffffff	/* Maximum unsigned 32-bit quantity */
72
73struct hdr {
74    uint32_t fmt;		/* Format */
75    uint32_t flags;		/* Bit flags */
76    uint32_t size;		/* Size of file */
77    uint32_t text;		/* Size of text segment */
78    uint32_t data;		/* Size of data segment */
79    uint32_t bss;		/* Size of bss segment */
80    uint32_t org;		/* Program origin */
81    uint32_t entry;		/* Program entry point */
82};
83
84static const char *const fmtlist[] = {"bin", "aout", "elf"};
85
86static const char binfo[] =
87    "kernel: ver=%u.%02u size=%x load=%x entry=%x map=%uM "
88    "pgctl=%x:%x\n";
89static const char cinfo[] =
90    "client: fmt=%s size=%x text=%x data=%x bss=%x entry=%x\n";
91static const char oinfo[] =
92    "output: fmt=%s size=%x text=%x data=%x org=%x entry=%x\n";
93
94static const char *lname =
95    BTX_PATH "/btxldr/btxldr";	/* BTX loader */
96static const char *bname =
97    BTX_PATH "/btx/btx";	/* BTX kernel */
98static const char *oname =
99    "a.out";			/* Output filename */
100
101static int ppage = -1;		/* First page present */
102static int wpage = -1;		/* First page writable */
103
104static unsigned int format; 	/* Output format */
105
106static uint32_t centry; 	/* Client entry address */
107static uint32_t lentry; 	/* Loader entry address */
108
109static int Eflag;		/* Client entry option */
110
111static int quiet;		/* Inhibit warnings */
112static int verbose;		/* Display information */
113
114static const char *tname;	/* Temporary output file */
115static const char *fname;	/* Current input file */
116
117static void cleanup(void);
118static void btxld(const char *);
119static void getbtx(int, struct btx_hdr *);
120static void gethdr(int, struct hdr *);
121static void puthdr(int, struct hdr *);
122static void copy(int, int, size_t, off_t);
123static size_t readx(int, void *, size_t, off_t);
124static void writex(int, const void *, size_t);
125static void seekx(int, off_t);
126static unsigned int optfmt(const char *);
127static uint32_t optaddr(const char *);
128static int optpage(const char *, int);
129static void Warn(const char *, const char *, ...);
130static void usage(void);
131
132/*
133 * A link editor for BTX clients.
134 */
135int
136main(int argc, char *argv[])
137{
138    int c;
139
140    while ((c = getopt(argc, argv, "qvb:E:e:f:l:o:P:W:")) != -1)
141	switch (c) {
142	case 'q':
143	    quiet = 1;
144	    break;
145	case 'v':
146	    verbose = 1;
147	    break;
148	case 'b':
149	    bname = optarg;
150	    break;
151	case 'E':
152	    centry = optaddr(optarg);
153	    Eflag = 1;
154	    break;
155	case 'e':
156	    lentry = optaddr(optarg);
157	    break;
158	case 'f':
159	    format = optfmt(optarg);
160	    break;
161	case 'l':
162	    lname = optarg;
163	    break;
164	case 'o':
165	    oname = optarg;
166	    break;
167	case 'P':
168	    ppage = optpage(optarg, 1);
169	    break;
170	case 'W':
171	    wpage = optpage(optarg, BTX_MAXCWR);
172	    break;
173	default:
174	    usage();
175	}
176    argc -= optind;
177    argv += optind;
178    if (argc != 1)
179	usage();
180    atexit(cleanup);
181    btxld(*argv);
182    return 0;
183}
184
185/*
186 * Clean up after errors.
187 */
188static void
189cleanup(void)
190{
191    if (tname)
192	(void)remove(tname);
193}
194
195/*
196 * Read the input files; write the output file; display information.
197 */
198static void
199btxld(const char *iname)
200{
201    char name[FILENAME_MAX];
202    struct btx_hdr btx, btxle;
203    struct hdr ihdr, ohdr;
204    unsigned int ldr_size, cwr;
205    int fdi[3], fdo, i;
206
207    ldr_size = 0;
208
209    for (i = I_LDR; i <= I_CLNT; i++) {
210	fname = i == I_LDR ? lname : i == I_BTX ? bname : iname;
211	if ((fdi[i] = open(fname, O_RDONLY)) == -1)
212	    err(2, "%s", fname);
213	switch (i) {
214	case I_LDR:
215	    gethdr(fdi[i], &ihdr);
216	    if (ihdr.fmt != F_BIN)
217		Warn(fname, "Loader format is %s; processing as %s",
218		     fmtlist[ihdr.fmt], fmtlist[F_BIN]);
219	    ldr_size = ihdr.size;
220	    break;
221	case I_BTX:
222	    getbtx(fdi[i], &btx);
223	    break;
224	case I_CLNT:
225	    gethdr(fdi[i], &ihdr);
226	    if (ihdr.org && ihdr.org != BTX_PGSIZE)
227		Warn(fname,
228		     "Client origin is 0x%x; expecting 0 or 0x%x",
229		     ihdr.org, BTX_PGSIZE);
230	}
231    }
232    memset(&ohdr, 0, sizeof(ohdr));
233    ohdr.fmt = format;
234    ohdr.text = ldr_size;
235    ohdr.data = btx.btx_textsz + ihdr.size;
236    ohdr.org = lentry;
237    ohdr.entry = lentry;
238    cwr = 0;
239    if (wpage > 0 || (wpage == -1 && !(ihdr.flags & IMPURE))) {
240	if (wpage > 0)
241	    cwr = wpage;
242	else {
243	    cwr = howmany(ihdr.text, BTX_PGSIZE);
244	    if (cwr > BTX_MAXCWR)
245		cwr = BTX_MAXCWR;
246	}
247    }
248    if (ppage > 0 || (ppage && wpage && ihdr.org >= BTX_PGSIZE)) {
249	btx.btx_flags |= BTX_MAPONE;
250	if (!cwr)
251	    cwr++;
252    }
253    btx.btx_pgctl -= cwr;
254    btx.btx_entry = Eflag ? centry : ihdr.entry;
255    if ((size_t)snprintf(name, sizeof(name), "%s.tmp", oname) >= sizeof(name))
256	errx(2, "%s: Filename too long", oname);
257    if ((fdo = open(name, O_CREAT | O_TRUNC | O_WRONLY, 0666)) == -1)
258	err(2, "%s", name);
259    if (!(tname = strdup(name)))
260	err(2, NULL);
261    puthdr(fdo, &ohdr);
262    for (i = I_LDR; i <= I_CLNT; i++) {
263	fname = i == I_LDR ? lname : i == I_BTX ? bname : iname;
264	switch (i) {
265	case I_LDR:
266	    copy(fdi[i], fdo, ldr_size, 0);
267	    seekx(fdo, ohdr.size += ohdr.text);
268	    break;
269	case I_BTX:
270	    btxle = btx;
271	    btxle.btx_pgctl = htole16(btxle.btx_pgctl);
272	    btxle.btx_textsz = htole16(btxle.btx_textsz);
273	    btxle.btx_entry = htole32(btxle.btx_entry);
274	    writex(fdo, &btxle, sizeof(btxle));
275	    copy(fdi[i], fdo, btx.btx_textsz - sizeof(btx),
276		 sizeof(btx));
277	    break;
278	case I_CLNT:
279	    copy(fdi[i], fdo, ihdr.size, 0);
280	    if (ftruncate(fdo, ohdr.size += ohdr.data))
281		err(2, "%s", tname);
282	}
283	if (close(fdi[i]))
284	    err(2, "%s", fname);
285    }
286    if (close(fdo))
287	err(2, "%s", tname);
288    if (rename(tname, oname))
289	err(2, "%s: Can't rename to %s", tname, oname);
290    free((void*)(intptr_t)tname);
291    tname = NULL;
292    if (verbose) {
293	printf(binfo, btx.btx_majver, btx.btx_minver, btx.btx_textsz,
294	       BTX_ORIGIN(btx), BTX_ENTRY(btx), BTX_MAPPED(btx) *
295	       BTX_PGSIZE / 0x100000, !!(btx.btx_flags & BTX_MAPONE),
296	       BTX_MAPPED(btx) - btx.btx_pgctl - BTX_PGBASE /
297	       BTX_PGSIZE - BTX_MAPPED(btx) * 4 / BTX_PGSIZE);
298	printf(cinfo, fmtlist[ihdr.fmt], ihdr.size, ihdr.text,
299	       ihdr.data, ihdr.bss, ihdr.entry);
300	printf(oinfo, fmtlist[ohdr.fmt], ohdr.size, ohdr.text,
301	       ohdr.data, ohdr.org, ohdr.entry);
302    }
303}
304
305/*
306 * Read BTX file header.
307 */
308static void
309getbtx(int fd, struct btx_hdr * btx)
310{
311    if (readx(fd, btx, sizeof(*btx), 0) != sizeof(*btx) ||
312	btx->btx_magic[0] != BTX_MAG0 ||
313	btx->btx_magic[1] != BTX_MAG1 ||
314	btx->btx_magic[2] != BTX_MAG2)
315	errx(1, "%s: Not a BTX kernel", fname);
316    btx->btx_pgctl = le16toh(btx->btx_pgctl);
317    btx->btx_textsz = le16toh(btx->btx_textsz);
318    btx->btx_entry = le32toh(btx->btx_entry);
319}
320
321/*
322 * Get file size and read a.out or ELF header.
323 */
324static void
325gethdr(int fd, struct hdr *hdr)
326{
327    struct stat sb;
328    const struct exec *ex;
329    const Elf32_Ehdr *ee;
330    const Elf32_Phdr *ep;
331    void *p;
332    unsigned int fmt, x, n, i;
333
334    memset(hdr, 0, sizeof(*hdr));
335    if (fstat(fd, &sb))
336	err(2, "%s", fname);
337    if (sb.st_size > MAXU32)
338	errx(1, "%s: Too big", fname);
339    hdr->size = sb.st_size;
340    if (!hdr->size)
341	return;
342    if ((p = mmap(NULL, hdr->size, PROT_READ, MAP_SHARED, fd,
343		  0)) == MAP_FAILED)
344	err(2, "%s", fname);
345    for (fmt = F_CNT - 1; !hdr->fmt && fmt; fmt--)
346	switch (fmt) {
347	case F_AOUT:
348	    ex = p;
349	    if (hdr->size >= sizeof(struct exec) && !N_BADMAG(*ex)) {
350		hdr->fmt = fmt;
351		x = N_GETMAGIC(*ex);
352		if (x == OMAGIC || x == NMAGIC) {
353		    if (x == NMAGIC)
354			Warn(fname, "Treating %s NMAGIC as OMAGIC",
355			     fmtlist[fmt]);
356		    hdr->flags |= IMPURE;
357		}
358		hdr->text = le32toh(ex->a_text);
359		hdr->data = le32toh(ex->a_data);
360		hdr->bss = le32toh(ex->a_bss);
361		hdr->entry = le32toh(ex->a_entry);
362		if (le32toh(ex->a_entry) >= BTX_PGSIZE)
363		    hdr->org = BTX_PGSIZE;
364	    }
365	    break;
366	case F_ELF:
367	    ee = p;
368	    if (hdr->size >= sizeof(Elf32_Ehdr) && IS_ELF(*ee)) {
369		hdr->fmt = fmt;
370		for (n = i = 0; i < le16toh(ee->e_phnum); i++) {
371		    ep = (void *)((uint8_t *)p + le32toh(ee->e_phoff) +
372				  le16toh(ee->e_phentsize) * i);
373		    if (le32toh(ep->p_type) == PT_LOAD)
374			switch (n++) {
375			case 0:
376			    hdr->text = le32toh(ep->p_filesz);
377			    hdr->org = le32toh(ep->p_paddr);
378			    if (le32toh(ep->p_flags) & PF_W)
379				hdr->flags |= IMPURE;
380			    break;
381			case 1:
382			    hdr->data = le32toh(ep->p_filesz);
383			    hdr->bss = le32toh(ep->p_memsz) -
384				le32toh(ep->p_filesz);
385			    break;
386			case 2:
387			    Warn(fname,
388				 "Ignoring extra %s PT_LOAD segments",
389				 fmtlist[fmt]);
390			}
391		}
392		hdr->entry = le32toh(ee->e_entry);
393	    }
394	}
395    if (munmap(p, hdr->size))
396	err(2, "%s", fname);
397}
398
399/*
400 * Write a.out or ELF header.
401 */
402static void
403puthdr(int fd, struct hdr *hdr)
404{
405    struct exec ex;
406    struct elfh eh;
407
408    switch (hdr->fmt) {
409    case F_AOUT:
410	memset(&ex, 0, sizeof(ex));
411	N_SETMAGIC(ex, ZMAGIC, MID_I386, 0);
412	hdr->text = N_ALIGN(ex, hdr->text);
413	ex.a_text = htole32(hdr->text);
414	hdr->data = N_ALIGN(ex, hdr->data);
415	ex.a_data = htole32(hdr->data);
416	ex.a_entry = htole32(hdr->entry);
417	writex(fd, &ex, sizeof(ex));
418	hdr->size = N_ALIGN(ex, sizeof(ex));
419	seekx(fd, hdr->size);
420	break;
421    case F_ELF:
422	eh = elfhdr;
423	eh.e.e_entry = htole32(hdr->entry);
424	eh.p[0].p_vaddr = eh.p[0].p_paddr = htole32(hdr->org);
425	eh.p[0].p_filesz = eh.p[0].p_memsz = htole32(hdr->text);
426	eh.p[1].p_offset = htole32(le32toh(eh.p[0].p_offset) +
427	    le32toh(eh.p[0].p_filesz));
428	eh.p[1].p_vaddr = eh.p[1].p_paddr =
429	    htole32(roundup2(le32toh(eh.p[0].p_paddr) + le32toh(eh.p[0].p_memsz),
430	    4096));
431	eh.p[1].p_filesz = eh.p[1].p_memsz = htole32(hdr->data);
432	eh.sh[2].sh_addr = eh.p[0].p_vaddr;
433	eh.sh[2].sh_offset = eh.p[0].p_offset;
434	eh.sh[2].sh_size = eh.p[0].p_filesz;
435	eh.sh[3].sh_addr = eh.p[1].p_vaddr;
436	eh.sh[3].sh_offset = eh.p[1].p_offset;
437	eh.sh[3].sh_size = eh.p[1].p_filesz;
438	writex(fd, &eh, sizeof(eh));
439	hdr->size = sizeof(eh);
440    }
441}
442
443/*
444 * Safe copy from input file to output file.
445 */
446static void
447copy(int fdi, int fdo, size_t nbyte, off_t offset)
448{
449    char buf[8192];
450    size_t n;
451
452    while (nbyte) {
453	if ((n = sizeof(buf)) > nbyte)
454	    n = nbyte;
455	if (readx(fdi, buf, n, offset) != n)
456	    errx(2, "%s: Short read", fname);
457	writex(fdo, buf, n);
458	nbyte -= n;
459	offset = -1;
460    }
461}
462
463/*
464 * Safe read from input file.
465 */
466static size_t
467readx(int fd, void *buf, size_t nbyte, off_t offset)
468{
469    ssize_t n;
470
471    if (offset != -1 && lseek(fd, offset, SEEK_SET) != offset)
472	err(2, "%s", fname);
473    if ((n = read(fd, buf, nbyte)) == -1)
474	err(2, "%s", fname);
475    return n;
476}
477
478/*
479 * Safe write to output file.
480 */
481static void
482writex(int fd, const void *buf, size_t nbyte)
483{
484    ssize_t n;
485
486    if ((n = write(fd, buf, nbyte)) == -1)
487	err(2, "%s", tname);
488    if ((size_t)n != nbyte)
489	errx(2, "%s: Short write", tname);
490}
491
492/*
493 * Safe seek in output file.
494 */
495static void
496seekx(int fd, off_t offset)
497{
498    if (lseek(fd, offset, SEEK_SET) != offset)
499	err(2, "%s", tname);
500}
501
502/*
503 * Convert an option argument to a format code.
504 */
505static unsigned int
506optfmt(const char *arg)
507{
508    unsigned int i;
509
510    for (i = 0; i < F_CNT && strcmp(arg, fmtlist[i]); i++);
511    if (i == F_CNT)
512	errx(1, "%s: Unknown format", arg);
513    return i;
514}
515
516/*
517 * Convert an option argument to an address.
518 */
519static uint32_t
520optaddr(const char *arg)
521{
522    char *s;
523    unsigned long x;
524
525    errno = 0;
526    x = strtoul(arg, &s, 0);
527    if (errno || !*arg || *s || x > MAXU32)
528	errx(1, "%s: Illegal address", arg);
529    return x;
530}
531
532/*
533 * Convert an option argument to a page number.
534 */
535static int
536optpage(const char *arg, int hi)
537{
538    char *s;
539    long x;
540
541    errno = 0;
542    x = strtol(arg, &s, 0);
543    if (errno || !*arg || *s || x < 0 || x > hi)
544	errx(1, "%s: Illegal page number", arg);
545    return x;
546}
547
548/*
549 * Display a warning.
550 */
551static void
552Warn(const char *locus, const char *fmt, ...)
553{
554    va_list ap;
555    char *s;
556
557    if (!quiet) {
558	asprintf(&s, "%s: Warning: %s", locus, fmt);
559	va_start(ap, fmt);
560	vwarnx(s, ap);
561	va_end(ap);
562	free(s);
563    }
564}
565
566/*
567 * Display usage information.
568 */
569static void
570usage(void)
571{
572    fprintf(stderr, "%s\n%s\n",
573    "usage: btxld [-qv] [-b file] [-E address] [-e address] [-f format]",
574    "             [-l file] [-o filename] [-P page] [-W page] file");
575    exit(1);
576}
577