xref: /inferno-os/utils/libmach/executable.c (revision 7e00430948d8af545f880e82bb30cd3ee50deb04)
1 #include	<lib9.h>
2 #include	<bio.h>
3 #include	"bootexec.h"
4 #include	"mach.h"
5 #include	"elf.h"
6 
7 /*
8  *	All a.out header types.  The dummy entry allows canonical
9  *	processing of the union as a sequence of longs
10  */
11 
12 typedef struct {
13 	union{
14 		Exec exec;			/* in a.out.h */
15 		Ehdr ehdr;			/* in elf.h */
16 		struct mipsexec mipsexec;
17 		struct mips4kexec mips4kexec;
18 		struct sparcexec sparcexec;
19 		struct nextexec nextexec;
20 	} e;
21 	long dummy;		/* padding to ensure extra long */
22 } ExecHdr;
23 
24 static	int	nextboot(int, Fhdr*, ExecHdr*);
25 static	int	sparcboot(int, Fhdr*, ExecHdr*);
26 static	int	mipsboot(int, Fhdr*, ExecHdr*);
27 static	int	mips4kboot(int, Fhdr*, ExecHdr*);
28 static	int	common(int, Fhdr*, ExecHdr*);
29 static	int	adotout(int, Fhdr*, ExecHdr*);
30 static	int	elfdotout(int, Fhdr*, ExecHdr*);
31 static	int	armdotout(int, Fhdr*, ExecHdr*);
32 static	void	setsym(Fhdr*, long, long, long, long);
33 static	void	setdata(Fhdr*, long, long, long, long);
34 static	void	settext(Fhdr*, long, long, long, long);
35 static	void	hswal(long*, int, long(*)(long));
36 static	long	_round(long, long);
37 
38 /*
39  *	definition of per-executable file type structures
40  */
41 
42 typedef struct Exectable{
43 	long	magic;			/* big-endian magic number of file */
44 	char	*name;			/* executable identifier */
45 	int	type;			/* Internal code */
46 	Mach	*mach;			/* Per-machine data */
47 	ulong	hsize;			/* header size */
48 	long	(*swal)(long);		/* beswal or leswal */
49 	int	(*hparse)(int, Fhdr*, ExecHdr*);
50 } ExecTable;
51 
52 extern	Mach	mmips;
53 extern	Mach	mmips2le;
54 extern	Mach	mmips2be;
55 extern	Mach	msparc;
56 extern	Mach	m68020;
57 extern	Mach	mi386;
58 extern	Mach	marm;
59 extern	Mach	mpower;
60 
61 ExecTable exectab[] =
62 {
63 	{ V_MAGIC,			/* Mips v.out */
64 		"mips plan 9 executable",
65 		FMIPS,
66 		&mmips,
67 		sizeof(Exec),
68 		beswal,
69 		adotout },
70 	{ M_MAGIC,			/* Mips 4.out */
71 		"mips 4k plan 9 executable BE",
72 		FMIPS2BE,
73 		&mmips2be,
74 		sizeof(Exec),
75 		beswal,
76 		adotout },
77 	{ N_MAGIC,			/* Mips 0.out */
78 		"mips 4k plan 9 executable LE",
79 		FMIPS2LE,
80 		&mmips2le,
81 		sizeof(Exec),
82 		beswal,
83 		adotout },
84 	{ 0x160<<16,			/* Mips boot image */
85 		"mips plan 9 boot image",
86 		FMIPSB,
87 		&mmips,
88 		sizeof(struct mipsexec),
89 		beswal,
90 		mipsboot },
91 	{ (0x160<<16)|3,		/* Mips boot image */
92 		"mips 4k plan 9 boot image",
93 		FMIPSB,
94 		&mmips,
95 		sizeof(struct mips4kexec),
96 		beswal,
97 		mips4kboot },
98 	{ K_MAGIC,			/* Sparc k.out */
99 		"sparc plan 9 executable",
100 		FSPARC,
101 		&msparc,
102 		sizeof(Exec),
103 		beswal,
104 		adotout },
105 	{ 0x01030107, 			/* Sparc boot image */
106 		"sparc plan 9 boot image",
107 		FSPARCB,
108 		&msparc,
109 		sizeof(struct sparcexec),
110 		beswal,
111 		sparcboot },
112 	{ A_MAGIC,			/* 68020 2.out & boot image */
113 		"68020 plan 9 executable",
114 		F68020,
115 		&m68020,
116 		sizeof(Exec),
117 		beswal,
118 		common },
119 	{ 0xFEEDFACE,			/* Next boot image */
120 		"next plan 9 boot image",
121 		FNEXTB,
122 		&m68020,
123 		sizeof(struct nextexec),
124 		beswal,
125 		nextboot },
126 	{ I_MAGIC,			/* I386 8.out & boot image */
127 		"386 plan 9 executable",
128 		FI386,
129 		&mi386,
130 		sizeof(Exec),
131 		beswal,
132 		common },
133 	{ ELF_MAG,
134 		"Irix 5.X Elf executable",
135 		FMIPS,
136 		&mmips,
137 		sizeof(Ehdr),
138 		beswal,
139 		elfdotout },
140 	{ E_MAGIC,			/* Arm 5.out */
141 		"Arm plan 9 executable",
142 		FARM,
143 		&marm,
144 		sizeof(Exec),
145 		beswal,
146 		common },
147 	{ (143<<16)|0413,		/* (Free|Net)BSD Arm */
148 		"Arm *BSD executable",
149 		FARM,
150 		&marm,
151 		sizeof(Exec),
152 		leswal,
153 		armdotout },
154 	{ Q_MAGIC,			/* PowerPC q.out */
155 		"power plan 9 executable",
156 		FPOWER,
157 		&mpower,
158 		sizeof(Exec),
159 		beswal,
160 		common },
161 	{ 0 },
162 };
163 
164 Mach	*mach = &mmips;			/* Global current machine table */
165 
166 ExecTable*
167 couldbe4k(ExecTable *mp)
168 {
169 	Dir *d;
170 	ExecTable *f;
171 
172 	if((d=dirstat("/proc/1/regs")) == nil)
173 		return mp;
174 	if(d->length < 32*8){		/* R3000 */
175 		free(d);
176 		return mp;
177 	}
178 	free(d);
179 	for (f = exectab; f->magic; f++)
180 		if(f->magic == M_MAGIC) {
181 			f->name = "mips plan 9 executable on mips2 kernel";
182 			return f;
183 		}
184 	return mp;
185 }
186 
187 
188 int
189 crackhdr(int fd, Fhdr *fp)
190 {
191 	ExecTable *mp;
192 	ExecHdr d;
193 	int nb, magic, ret;
194 
195 	fp->type = FNONE;
196 	nb = read(fd, (char *)&d.e, sizeof(d.e));
197 	if (nb <= 0)
198 		return 0;
199 
200 	ret = 0;
201 	fp->magic = magic = beswal(d.e.exec.magic);		/* big-endian */
202 	for (mp = exectab; mp->magic; mp++) {
203 		if (mp->magic == magic && nb >= mp->hsize) {
204 			if(mp->magic == V_MAGIC)
205 				mp = couldbe4k(mp);
206 
207 			hswal((long *) &d, sizeof(d.e)/sizeof(long), mp->swal);
208 			fp->type = mp->type;
209 			fp->name = mp->name;
210 			fp->hdrsz = mp->hsize;		/* zero on bootables */
211 			mach = mp->mach;
212 			ret  = mp->hparse(fd, fp, &d);
213 			seek(fd, mp->hsize, 0);		/* seek to end of header */
214 			break;
215 		}
216 	}
217 	if(mp->magic == 0)
218 		werrstr("unknown header type");
219 	return ret;
220 }
221 /*
222  * Convert header to canonical form
223  */
224 static void
225 hswal(long *lp, int n, long (*swap) (long))
226 {
227 	while (n--) {
228 		*lp = (*swap) (*lp);
229 		lp++;
230 	}
231 }
232 /*
233  *	Crack a normal a.out-type header
234  */
235 static int
236 adotout(int fd, Fhdr *fp, ExecHdr *hp)
237 {
238 	long pgsize;
239 
240 	USED(fd);
241 	pgsize = mach->pgsize;
242 	settext(fp, hp->e.exec.entry, pgsize+sizeof(Exec),
243 			hp->e.exec.text, sizeof(Exec));
244 	setdata(fp, _round(pgsize+fp->txtsz+sizeof(Exec), pgsize),
245 		hp->e.exec.data, fp->txtsz+sizeof(Exec), hp->e.exec.bss);
246 	setsym(fp, hp->e.exec.syms, hp->e.exec.spsz, hp->e.exec.pcsz, fp->datoff+fp->datsz);
247 	return 1;
248 }
249 
250 /*
251  *	68020 2.out and 68020 bootable images
252  *	386I 8.out and 386I bootable images
253  *
254  */
255 static int
256 common(int fd, Fhdr *fp, ExecHdr *hp)
257 {
258 	long kbase;
259 
260 	adotout(fd, fp, hp);
261 	kbase = mach->kbase;
262 	if ((fp->entry & kbase) == kbase) {		/* Boot image */
263 		switch(fp->type) {
264 		case F68020:
265 			fp->type = F68020B;
266 			fp->name = "68020 plan 9 boot image";
267 			fp->hdrsz = 0;		/* header stripped */
268 			break;
269 		case FI386:
270 			fp->type = FI386B;
271 			fp->txtaddr = sizeof(Exec);
272 			fp->name = "386 plan 9 boot image";
273 			fp->hdrsz = 0;		/* header stripped */
274 			fp->dataddr = fp->txtaddr+fp->txtsz;
275 			break;
276 		case FARM:
277 			fp->txtaddr = kbase+0x8000+sizeof(Exec);
278 			fp->name = "ARM plan 9 boot image";
279 			fp->hdrsz = 0;		/* header stripped */
280 			fp->dataddr = fp->txtaddr+fp->txtsz;
281 			return 1;
282 		default:
283 			break;
284 		}
285 		fp->txtaddr |= kbase;
286 		fp->entry |= kbase;
287 		fp->dataddr |= kbase;
288 	}
289 	else if (fp->type == FARM && (fp->entry == 0x8020 || fp->entry == 0x8080)) {
290 		fp->txtaddr = fp->entry;
291 		fp->name = "ARM Inferno boot image";
292 		fp->hdrsz = 0;		/* header stripped */
293 		fp->dataddr = fp->txtaddr+fp->txtsz;
294 	}
295 	else if (fp->type == FPOWER && fp->entry == 0x3020) {
296 		fp->txtaddr = fp->entry;
297 		fp->name = "Power Inferno boot image";
298 		fp->hdrsz = 0;		/* header stripped */
299 		fp->dataddr = fp->txtaddr+fp->txtsz;
300 	}
301 	return 1;
302 }
303 
304 /*
305  *	mips bootable image.
306  */
307 static int
308 mipsboot(int fd, Fhdr *fp, ExecHdr *hp)
309 {
310 	USED(fd);
311 	switch(hp->e.mipsexec.amagic) {
312 	default:
313 	case 0407:	/* some kind of mips */
314 		fp->type = FMIPSB;
315 		settext(fp, hp->e.mipsexec.mentry, hp->e.mipsexec.text_start, hp->e.mipsexec.tsize,
316 					sizeof(struct mipsexec)+4);
317 		setdata(fp, hp->e.mipsexec.data_start, hp->e.mipsexec.dsize,
318 				fp->txtoff+hp->e.mipsexec.tsize, hp->e.mipsexec.bsize);
319 		break;
320 	case 0413:	/* some kind of mips */
321 		fp->type = FMIPSB;
322 		settext(fp, hp->e.mipsexec.mentry, hp->e.mipsexec.text_start, hp->e.mipsexec.tsize, 0);
323 		setdata(fp, hp->e.mipsexec.data_start, hp->e.mipsexec.dsize, hp->e.mipsexec.tsize,
324 					hp->e.mipsexec.bsize);
325 		break;
326 	}
327 	setsym(fp, hp->e.mipsexec.nsyms, 0, hp->e.mipsexec.u0.mpcsize, hp->e.mipsexec.symptr);
328 	fp->hdrsz = 0;		/* header stripped */
329 	return 1;
330 }
331 
332 /*
333  *	mips4k bootable image.
334  */
335 static int
336 mips4kboot(int fd, Fhdr *fp, ExecHdr *hp)
337 {
338 	USED(fd);
339 	switch(hp->e.mipsexec.amagic) {
340 	default:
341 	case 0407:	/* some kind of mips */
342 		fp->type = FMIPSB;
343 		settext(fp, hp->e.mipsexec.mentry, hp->e.mipsexec.text_start, hp->e.mipsexec.tsize,
344 					sizeof(struct mips4kexec));
345 		setdata(fp, hp->e.mipsexec.data_start, hp->e.mipsexec.dsize,
346 				fp->txtoff+hp->e.mipsexec.tsize, hp->e.mipsexec.bsize);
347 		break;
348 	case 0413:	/* some kind of mips */
349 		fp->type = FMIPSB;
350 		settext(fp, hp->e.mipsexec.mentry, hp->e.mipsexec.text_start, hp->e.mipsexec.tsize, 0);
351 		setdata(fp, hp->e.mipsexec.data_start, hp->e.mipsexec.dsize, hp->e.mipsexec.tsize,
352 					hp->e.mipsexec.bsize);
353 		break;
354 	}
355 	setsym(fp, hp->e.mipsexec.nsyms, 0, hp->e.mipsexec.u0.mpcsize, hp->e.mipsexec.symptr);
356 	fp->hdrsz = 0;		/* header stripped */
357 	return 1;
358 }
359 
360 /*
361  *	sparc bootable image
362  */
363 static int
364 sparcboot(int fd, Fhdr *fp, ExecHdr *hp)
365 {
366 	USED(fd);
367 	fp->type = FSPARCB;
368 	settext(fp, hp->e.sparcexec.sentry, hp->e.sparcexec.sentry, hp->e.sparcexec.stext,
369 					sizeof(struct sparcexec));
370 	setdata(fp, hp->e.sparcexec.sentry+hp->e.sparcexec.stext, hp->e.sparcexec.sdata,
371 					fp->txtoff+hp->e.sparcexec.stext, hp->e.sparcexec.sbss);
372 	setsym(fp, hp->e.sparcexec.ssyms, 0, hp->e.sparcexec.sdrsize, fp->datoff+hp->e.sparcexec.sdata);
373 	fp->hdrsz = 0;		/* header stripped */
374 	return 1;
375 }
376 
377 /*
378  *	next bootable image
379  */
380 static int
381 nextboot(int fd, Fhdr *fp, ExecHdr *hp)
382 {
383 	USED(fd);
384 	fp->type = FNEXTB;
385 	settext(fp, hp->e.nextexec.textc.vmaddr, hp->e.nextexec.textc.vmaddr,
386 					hp->e.nextexec.texts.size, hp->e.nextexec.texts.offset);
387 	setdata(fp, hp->e.nextexec.datac.vmaddr, hp->e.nextexec.datas.size,
388 				hp->e.nextexec.datas.offset, hp->e.nextexec.bsss.size);
389 	setsym(fp, hp->e.nextexec.symc.nsyms, hp->e.nextexec.symc.spoff, hp->e.nextexec.symc.pcoff,
390 					hp->e.nextexec.symc.symoff);
391 	fp->hdrsz = 0;		/* header stripped */
392 	return 1;
393 }
394 
395 static Shdr*
396 elfsectbyname(int fd, Ehdr *hp, Shdr *sp, char *name)
397 {
398 	int i, offset, n;
399 	char s[64];
400 
401 	offset = sp[hp->shstrndx].offset;
402 	for(i = 1; i < hp->shnum; i++) {
403 		seek(fd, offset+sp[i].name, 0);
404 		n = read(fd, s, sizeof(s)-1);
405 		if(n < 0)
406 			continue;
407 		s[n] = 0;
408 		if(strcmp(s, name) == 0)
409 			return &sp[i];
410 	}
411 	return 0;
412 }
413 /*
414  *	Decode an Irix 5.x ELF header
415  */
416 static int
417 elfdotout(int fd, Fhdr *fp, ExecHdr *hp)
418 {
419 
420 	Ehdr *ep;
421 	Shdr *es, *txt, *init, *s;
422 	long addr, size, offset, bsize;
423 
424 	ep = &hp->e.ehdr;
425 	fp->magic = ELF_MAG;
426 	fp->hdrsz = (ep->ehsize+ep->phnum*ep->phentsize+16)&~15;
427 
428 	if(ep->shnum <= 0) {
429 		werrstr("no ELF header sections");
430 		return 0;
431 	}
432 	es = malloc(sizeof(Shdr)*ep->shnum);
433 	if(es == 0)
434 		return 0;
435 
436 	seek(fd, ep->shoff, 0);
437 	if(read(fd, es, sizeof(Shdr)*ep->shnum) < 0){
438 		free(es);
439 		return 0;
440 	}
441 
442 	txt = elfsectbyname(fd, ep, es, ".text");
443 	init = elfsectbyname(fd, ep, es, ".init");
444 	if(txt == 0 || init == 0 || init != txt+1)
445 		goto bad;
446 	if(txt->addr+txt->size != init->addr)
447 		goto bad;
448 	settext(fp, ep->elfentry, txt->addr, txt->size+init->size, txt->offset);
449 
450 	addr = 0;
451 	offset = 0;
452 	size = 0;
453 	s = elfsectbyname(fd, ep, es, ".data");
454 	if(s) {
455 		addr = s->addr;
456 		size = s->size;
457 		offset = s->offset;
458 	}
459 
460 	s = elfsectbyname(fd, ep, es, ".rodata");
461 	if(s) {
462 		if(addr){
463 			if(addr+size != s->addr)
464 				goto bad;
465 		} else {
466 			addr = s->addr;
467 			offset = s->offset;
468 		}
469 		size += s->size;
470 	}
471 
472 	s = elfsectbyname(fd, ep, es, ".got");
473 	if(s) {
474 		if(addr){
475 			if(addr+size != s->addr)
476 				goto bad;
477 		} else {
478 			addr = s->addr;
479 			offset = s->offset;
480 		}
481 		size += s->size;
482 	}
483 
484 	bsize = 0;
485 	s = elfsectbyname(fd, ep, es, ".bss");
486 	if(s) {
487 		if(addr){
488 			if(addr+size != s->addr)
489 				goto bad;
490 		} else {
491 			addr = s->addr;
492 			offset = s->offset;
493 		}
494 		bsize = s->size;
495 	}
496 
497 	if(addr == 0)
498 		goto bad;
499 
500 	setdata(fp, addr, size, offset, bsize);
501 	fp->name = "IRIX Elf a.out executable";
502 	free(es);
503 	return 1;
504 bad:
505 	free(es);
506 	werrstr("ELF sections scrambled");
507 	return 0;
508 }
509 
510 /*
511  * (Free|Net)BSD ARM header.
512  */
513 static int
514 armdotout(int fd, Fhdr *fp, ExecHdr *hp)
515 {
516 	long kbase;
517 
518 	USED(fd);
519 	settext(fp, hp->e.exec.entry, sizeof(Exec), hp->e.exec.text, sizeof(Exec));
520 	setdata(fp, fp->txtsz, hp->e.exec.data, fp->txtsz, hp->e.exec.bss);
521 	setsym(fp, hp->e.exec.syms, hp->e.exec.spsz, hp->e.exec.pcsz, fp->datoff+fp->datsz);
522 
523 	kbase = 0xF0000000;
524 	if ((fp->entry & kbase) == kbase) {		/* Boot image */
525 		fp->txtaddr = kbase+sizeof(Exec);
526 		fp->name = "ARM *BSD boot image";
527 		fp->hdrsz = 0;		/* header stripped */
528 		fp->dataddr = kbase+fp->txtsz;
529 	}
530 	return 1;
531 }
532 
533 static void
534 settext(Fhdr *fp, long e, long a, long s, long off)
535 {
536 	fp->txtaddr = a;
537 	fp->entry = e;
538 	fp->txtsz = s;
539 	fp->txtoff = off;
540 }
541 static void
542 setdata(Fhdr *fp, long a, long s, long off, long bss)
543 {
544 	fp->dataddr = a;
545 	fp->datsz = s;
546 	fp->datoff = off;
547 	fp->bsssz = bss;
548 }
549 static void
550 setsym(Fhdr *fp, long sy, long sppc, long lnpc, long symoff)
551 {
552 	fp->symsz = sy;
553 	fp->symoff = symoff;
554 	fp->sppcsz = sppc;
555 	fp->sppcoff = fp->symoff+fp->symsz;
556 	fp->lnpcsz = lnpc;
557 	fp->lnpcoff = fp->sppcoff+fp->sppcsz;
558 }
559 
560 
561 static long
562 _round(long a, long b)
563 {
564 	long w;
565 
566 	w = (a/b)*b;
567 	if (a!=w)
568 		w += b;
569 	return(w);
570 }
571