source: trunk/minix/boot/bootimage.c@ 10

Last change on this file since 10 was 9, checked in by Mattia Monga, 14 years ago

Minix 3.1.2a
File size: 18.1 KB
Line 
1/* bootimage.c - Load an image and start it. Author: Kees J. Bot
2 * 19 Jan 1992
3 */
4#define BIOS 1 /* Can only be used under the BIOS. */
5#define nil 0
6#define _POSIX_SOURCE 1
7#define _MINIX 1
8#include <stddef.h>
9#include <sys/types.h>
10#include <sys/stat.h>
11#include <stdlib.h>
12#include <stdio.h>
13#include <limits.h>
14#include <string.h>
15#include <errno.h>
16#include <a.out.h>
17#include <minix/config.h>
18#include <minix/const.h>
19#include <minix/type.h>
20#include <minix/syslib.h>
21#include <kernel/const.h>
22#include <kernel/type.h>
23#include <ibm/partition.h>
24#include "rawfs.h"
25#include "image.h"
26#include "boot.h"
27
28static int block_size = 0;
29
30#define click_shift clck_shft /* 7 char clash with click_size. */
31
32/* Some kernels have extra features: */
33#define K_I386 0x0001 /* Make the 386 transition before you call me. */
34#define K_CLAIM 0x0002 /* I will acquire my own bss pages, thank you. */
35#define K_CHMEM 0x0004 /* This kernel listens to chmem for its stack size. */
36#define K_HIGH 0x0008 /* Load mm, fs, etc. in extended memory. */
37#define K_HDR 0x0010 /* No need to patch sizes, kernel uses the headers. */
38#define K_RET 0x0020 /* Returns to the monitor on reboot. */
39#define K_INT86 0x0040 /* Requires generic INT support. */
40#define K_MEML 0x0080 /* Pass a list of free memory. */
41#define K_BRET 0x0100 /* New monitor code on shutdown in boot parameters. */
42#define K_ALL 0x01FF /* All feature bits this monitor supports. */
43
44
45/* Data about the different processes. */
46
47#define PROCESS_MAX 16 /* Must match the space in kernel/mpx.x */
48#define KERNEL 0 /* The first process is the kernel. */
49#define FS 2 /* The third must be fs. */
50
51struct process { /* Per-process memory adresses. */
52 u32_t entry; /* Entry point. */
53 u32_t cs; /* Code segment. */
54 u32_t ds; /* Data segment. */
55 u32_t data; /* To access the data segment. */
56 u32_t end; /* End of this process, size = (end - cs). */
57} process[PROCESS_MAX];
58int n_procs; /* Number of processes. */
59
60/* Magic numbers in process' data space. */
61#define MAGIC_OFF 0 /* Offset of magic # in data seg. */
62#define CLICK_OFF 2 /* Offset in kernel text to click_shift. */
63#define FLAGS_OFF 4 /* Offset in kernel text to flags. */
64#define KERNEL_D_MAGIC 0x526F /* Kernel magic number. */
65
66/* Offsets of sizes to be patched into kernel and fs. */
67#define P_SIZ_OFF 0 /* Process' sizes into kernel data. */
68#define P_INIT_OFF 4 /* Init cs & sizes into fs data. */
69
70
71#define between(a, c, z) ((unsigned) ((c) - (a)) <= ((z) - (a)))
72
73void pretty_image(char *image)
74/* Pretty print the name of the image to load. Translate '/' and '_' to
75 * space, first letter goes uppercase. An 'r' before a digit prints as
76 * 'revision'. E.g. 'minix/1.6.16r10' -> 'Minix 1.6.16 revision 10'.
77 * The idea is that the part before the 'r' is the official Minix release
78 * and after the 'r' you can put version numbers for your own changes.
79 */
80{
81 int up= 0, c;
82
83 while ((c= *image++) != 0) {
84 if (c == '/' || c == '_') c= ' ';
85
86 if (c == 'r' && between('0', *image, '9')) {
87 printf(" revision ");
88 continue;
89 }
90 if (!up && between('a', c, 'z')) c= c - 'a' + 'A';
91
92 if (between('A', c, 'Z')) up= 1;
93
94 putch(c);
95 }
96}
97
98void raw_clear(u32_t addr, u32_t count)
99/* Clear "count" bytes at absolute address "addr". */
100{
101 static char zeros[128];
102 u32_t dst;
103 u32_t zct;
104
105 zct= sizeof(zeros);
106 if (zct > count) zct= count;
107 raw_copy(addr, mon2abs(&zeros), zct);
108 count-= zct;
109
110 while (count > 0) {
111 dst= addr + zct;
112 if (zct > count) zct= count;
113 raw_copy(dst, addr, zct);
114 count-= zct;
115 zct*= 2;
116 }
117}
118
119/* Align a to a multiple of n (a power of 2): */
120#define align(a, n) (((u32_t)(a) + ((u32_t)(n) - 1)) & ~((u32_t)(n) - 1))
121unsigned click_shift;
122unsigned click_size; /* click_size = Smallest kernel memory object. */
123unsigned k_flags; /* Not all kernels are created equal. */
124u32_t reboot_code; /* Obsolete reboot code return pointer. */
125
126int params2params(char *params, size_t psize)
127/* Repackage the environment settings for the kernel. */
128{
129 size_t i, n;
130 environment *e;
131 char *name, *value;
132 dev_t dev;
133
134 i= 0;
135 for (e= env; e != nil; e= e->next) {
136 name= e->name;
137 value= e->value;
138
139 if (!(e->flags & E_VAR)) continue;
140
141 if (e->flags & E_DEV) {
142 if ((dev= name2dev(value)) == -1) return 0;
143 value= ul2a10((u16_t) dev);
144 }
145
146 n= i + strlen(name) + 1 + strlen(value) + 1;
147 if (n < psize) {
148 strcpy(params + i, name);
149 strcat(params + i, "=");
150 strcat(params + i, value);
151 }
152 i= n;
153 }
154
155 if (!(k_flags & K_MEML)) {
156 /* Require old memory size variables. */
157
158 value= ul2a10((mem[0].base + mem[0].size) / 1024);
159 n= i + 7 + 1 + strlen(value) + 1;
160 if (n < psize) {
161 strcpy(params + i, "memsize=");
162 strcat(params + i, value);
163 }
164 i= n;
165 value= ul2a10(mem[1].size / 1024);
166 n= i + 7 + 1 + strlen(value) + 1;
167 if (n < psize) {
168 strcpy(params + i, "emssize=");
169 strcat(params + i, value);
170 }
171 i= n;
172 }
173
174 if (i >= psize) {
175 printf("Too many boot parameters\n");
176 return 0;
177 }
178 params[i]= 0; /* End marked with empty string. */
179 return 1;
180}
181
182void patch_sizes(void)
183/* Patch sizes of each process into kernel data space, kernel ds into kernel
184 * text space, and sizes of init into data space of fs. All the patched
185 * numbers are based on the kernel click size, not hardware segments.
186 */
187{
188 u16_t text_size, data_size;
189 int i;
190 struct process *procp, *initp;
191 u32_t doff;
192
193 if (k_flags & K_HDR) return; /* Uses the headers. */
194
195 /* Patch text and data sizes of the processes into kernel data space.
196 */
197 doff= process[KERNEL].data + P_SIZ_OFF;
198
199 for (i= 0; i < n_procs; i++) {
200 procp= &process[i];
201 text_size= (procp->ds - procp->cs) >> click_shift;
202 data_size= (procp->end - procp->ds) >> click_shift;
203
204 /* Two words per process, the text and data size: */
205 put_word(doff, text_size); doff+= 2;
206 put_word(doff, data_size); doff+= 2;
207
208 initp= procp; /* The last process must be init. */
209 }
210
211 if (k_flags & (K_HIGH|K_MEML)) return; /* Doesn't need FS patching. */
212
213 /* Patch cs and sizes of init into fs data. */
214 put_word(process[FS].data + P_INIT_OFF+0, initp->cs >> click_shift);
215 put_word(process[FS].data + P_INIT_OFF+2, text_size);
216 put_word(process[FS].data + P_INIT_OFF+4, data_size);
217}
218
219int selected(char *name)
220/* True iff name has no label or the proper label. */
221{
222 char *colon, *label;
223 int cmp;
224
225 if ((colon= strchr(name, ':')) == nil) return 1;
226 if ((label= b_value("label")) == nil) return 1;
227
228 *colon= 0;
229 cmp= strcmp(label, name);
230 *colon= ':';
231 return cmp == 0;
232}
233
234u32_t proc_size(struct image_header *hdr)
235/* Return the size of a process in sectors as found in an image. */
236{
237 u32_t len= hdr->process.a_text;
238
239 if (hdr->process.a_flags & A_PAL) len+= hdr->process.a_hdrlen;
240 if (hdr->process.a_flags & A_SEP) len= align(len, SECTOR_SIZE);
241 len= align(len + hdr->process.a_data, SECTOR_SIZE);
242
243 return len >> SECTOR_SHIFT;
244}
245
246off_t image_off, image_size;
247u32_t (*vir2sec)(u32_t vsec); /* Where is a sector on disk? */
248
249u32_t file_vir2sec(u32_t vsec)
250/* Translate a virtual sector number to an absolute disk sector. */
251{
252 off_t blk;
253
254 if(!block_size) { errno = 0; return -1; }
255
256 if ((blk= r_vir2abs(vsec / RATIO(block_size))) == -1) {
257 errno= EIO;
258 return -1;
259 }
260 return blk == 0 ? 0 : lowsec + blk * RATIO(block_size) + vsec % RATIO(block_size);
261}
262
263u32_t flat_vir2sec(u32_t vsec)
264/* Simply add an absolute sector offset to vsec. */
265{
266 return lowsec + image_off + vsec;
267}
268
269char *get_sector(u32_t vsec)
270/* Read a sector "vsec" from the image into memory and return its address.
271 * Return nil on error. (This routine tries to read an entire track, so
272 * the next request is usually satisfied from the track buffer.)
273 */
274{
275 u32_t sec;
276 int r;
277#define SECBUFS 16
278 static char buf[SECBUFS * SECTOR_SIZE];
279 static size_t count; /* Number of sectors in the buffer. */
280 static u32_t bufsec; /* First Sector now in the buffer. */
281
282 if (vsec == 0) count= 0; /* First sector; initialize. */
283
284 if ((sec= (*vir2sec)(vsec)) == -1) return nil;
285
286 if (sec == 0) {
287 /* A hole. */
288 count= 0;
289 memset(buf, 0, SECTOR_SIZE);
290 return buf;
291 }
292
293 /* Can we return a sector from the buffer? */
294 if ((sec - bufsec) < count) {
295 return buf + ((size_t) (sec - bufsec) << SECTOR_SHIFT);
296 }
297
298 /* Not in the buffer. */
299 count= 0;
300 bufsec= sec;
301
302 /* Read a whole track if possible. */
303 while (++count < SECBUFS && !dev_boundary(bufsec + count)) {
304 vsec++;
305 if ((sec= (*vir2sec)(vsec)) == -1) break;
306
307 /* Consecutive? */
308 if (sec != bufsec + count) break;
309 }
310
311 /* Actually read the sectors. */
312 if ((r= readsectors(mon2abs(buf), bufsec, count)) != 0) {
313 readerr(bufsec, r);
314 count= 0;
315 errno= 0;
316 return nil;
317 }
318 return buf;
319}
320
321int get_clickshift(u32_t ksec, struct image_header *hdr)
322/* Get the click shift and special flags from kernel text. */
323{
324 char *textp;
325
326 if ((textp= get_sector(ksec)) == nil) return 0;
327
328 if (hdr->process.a_flags & A_PAL) textp+= hdr->process.a_hdrlen;
329 click_shift= * (u16_t *) (textp + CLICK_OFF);
330 k_flags= * (u16_t *) (textp + FLAGS_OFF);
331
332 if ((k_flags & ~K_ALL) != 0) {
333 printf("%s requires features this monitor doesn't offer\n",
334 hdr->name);
335 return 0;
336 }
337
338 if (click_shift < HCLICK_SHIFT || click_shift > 16) {
339 printf("%s click size is bad\n", hdr->name);
340 errno= 0;
341 return 0;
342 }
343
344 click_size= 1 << click_shift;
345
346 return 1;
347}
348
349int get_segment(u32_t *vsec, long *size, u32_t *addr, u32_t limit)
350/* Read *size bytes starting at virtual sector *vsec to memory at *addr. */
351{
352 char *buf;
353 size_t cnt, n;
354
355 cnt= 0;
356 while (*size > 0) {
357 if (cnt == 0) {
358 if ((buf= get_sector((*vsec)++)) == nil) return 0;
359 cnt= SECTOR_SIZE;
360 }
361 if (*addr + click_size > limit) { errno= ENOMEM; return 0; }
362 n= click_size;
363 if (n > cnt) n= cnt;
364 raw_copy(*addr, mon2abs(buf), n);
365 *addr+= n;
366 *size-= n;
367 buf+= n;
368 cnt-= n;
369 }
370
371 /* Zero extend to a click. */
372 n= align(*addr, click_size) - *addr;
373 raw_clear(*addr, n);
374 *addr+= n;
375 *size-= n;
376 return 1;
377}
378
379void exec_image(char *image)
380/* Get a Minix image into core, patch it up and execute. */
381{
382 char *delayvalue;
383 int i;
384 struct image_header hdr;
385 char *buf;
386 u32_t vsec, addr, limit, aout, n;
387 struct process *procp; /* Process under construction. */
388 long a_text, a_data, a_bss, a_stack;
389 int banner= 0;
390 long processor= a2l(b_value("processor"));
391 u16_t mode;
392 char *console;
393 char params[SECTOR_SIZE];
394 extern char *sbrk(int);
395
396 /* The stack is pretty deep here, so check if heap and stack collide. */
397 (void) sbrk(0);
398
399 printf("\nLoading ");
400 pretty_image(image);
401 printf(".\n\n");
402
403 vsec= 0; /* Load this sector from image next. */
404 addr= mem[0].base; /* Into this memory block. */
405 limit= mem[0].base + mem[0].size;
406 if (limit > caddr) limit= caddr;
407
408 /* Allocate and clear the area where the headers will be placed. */
409 aout = (limit -= PROCESS_MAX * A_MINHDR);
410
411 /* Clear the area where the headers will be placed. */
412 raw_clear(aout, PROCESS_MAX * A_MINHDR);
413
414 /* Read the many different processes: */
415 for (i= 0; vsec < image_size; i++) {
416 if (i == PROCESS_MAX) {
417 printf("There are more then %d programs in %s\n",
418 PROCESS_MAX, image);
419 errno= 0;
420 return;
421 }
422 procp= &process[i];
423
424 /* Read header. */
425 for (;;) {
426 if ((buf= get_sector(vsec++)) == nil) return;
427
428 memcpy(&hdr, buf, sizeof(hdr));
429
430 if (BADMAG(hdr.process)) { errno= ENOEXEC; return; }
431
432 /* Check the optional label on the process. */
433 if (selected(hdr.name)) break;
434
435 /* Bad label, skip this process. */
436 vsec+= proc_size(&hdr);
437 }
438
439 /* Sanity check: an 8086 can't run a 386 kernel. */
440 if (hdr.process.a_cpu == A_I80386 && processor < 386) {
441 printf("You can't run a 386 kernel on this 80%ld\n",
442 processor);
443 errno= 0;
444 return;
445 }
446
447 /* Get the click shift from the kernel text segment. */
448 if (i == KERNEL) {
449 if (!get_clickshift(vsec, &hdr)) return;
450 addr= align(addr, click_size);
451 }
452
453 /* Save a copy of the header for the kernel, with a_syms
454 * misused as the address where the process is loaded at.
455 */
456 hdr.process.a_syms= addr;
457 raw_copy(aout + i * A_MINHDR, mon2abs(&hdr.process), A_MINHDR);
458
459 if (!banner) {
460 printf(" cs ds text data bss");
461 if (k_flags & K_CHMEM) printf(" stack");
462 putch('\n');
463 banner= 1;
464 }
465
466 /* Segment sizes. */
467 a_text= hdr.process.a_text;
468 a_data= hdr.process.a_data;
469 a_bss= hdr.process.a_bss;
470 if (k_flags & K_CHMEM) {
471 a_stack= hdr.process.a_total - a_data - a_bss;
472 if (!(hdr.process.a_flags & A_SEP)) a_stack-= a_text;
473 } else {
474 a_stack= 0;
475 }
476
477 /* Collect info about the process to be. */
478 procp->cs= addr;
479
480 /* Process may be page aligned so that the text segment contains
481 * the header, or have an unmapped zero page against vaxisms.
482 */
483 procp->entry= hdr.process.a_entry;
484 if (hdr.process.a_flags & A_PAL) a_text+= hdr.process.a_hdrlen;
485 if (hdr.process.a_flags & A_UZP) procp->cs-= click_size;
486
487 /* Separate I&D: two segments. Common I&D: only one. */
488 if (hdr.process.a_flags & A_SEP) {
489 /* Read the text segment. */
490 if (!get_segment(&vsec, &a_text, &addr, limit)) return;
491
492 /* The data segment follows. */
493 procp->ds= addr;
494 if (hdr.process.a_flags & A_UZP) procp->ds-= click_size;
495 procp->data= addr;
496 } else {
497 /* Add text to data to form one segment. */
498 procp->data= addr + a_text;
499 procp->ds= procp->cs;
500 a_data+= a_text;
501 }
502
503 /* Read the data segment. */
504 if (!get_segment(&vsec, &a_data, &addr, limit)) return;
505
506 /* Make space for bss and stack unless... */
507 if (i != KERNEL && (k_flags & K_CLAIM)) a_bss= a_stack= 0;
508
509 printf("%07lx %07lx %8ld %8ld %8ld",
510 procp->cs, procp->ds,
511 hdr.process.a_text, hdr.process.a_data,
512 hdr.process.a_bss
513 );
514 if (k_flags & K_CHMEM) printf(" %8ld", a_stack);
515
516 printf(" %s\n", hdr.name);
517
518 /* Note that a_data may be negative now, but we can look at it
519 * as -a_data bss bytes.
520 */
521
522 /* Compute the number of bss clicks left. */
523 a_bss+= a_data;
524 n= align(a_bss, click_size);
525 a_bss-= n;
526
527 /* Zero out bss. */
528 if (addr + n > limit) { errno= ENOMEM; return; }
529 raw_clear(addr, n);
530 addr+= n;
531
532 /* And the number of stack clicks. */
533 a_stack+= a_bss;
534 n= align(a_stack, click_size);
535 a_stack-= n;
536
537 /* Add space for the stack. */
538 addr+= n;
539
540 /* Process endpoint. */
541 procp->end= addr;
542
543 if (i == 0 && (k_flags & K_HIGH)) {
544 /* Load the rest in extended memory. */
545 addr= mem[1].base;
546 limit= mem[1].base + mem[1].size;
547 }
548 }
549
550 if ((n_procs= i) == 0) {
551 printf("There are no programs in %s\n", image);
552 errno= 0;
553 return;
554 }
555
556 /* Check the kernel magic number. */
557 if (get_word(process[KERNEL].data + MAGIC_OFF) != KERNEL_D_MAGIC) {
558 printf("Kernel magic number is incorrect\n");
559 errno= 0;
560 return;
561 }
562
563 /* Patch sizes, etc. into kernel data. */
564 patch_sizes();
565
566#if !DOS
567 if (!(k_flags & K_MEML)) {
568 /* Copy the a.out headers to the old place. */
569 raw_copy(HEADERPOS, aout, PROCESS_MAX * A_MINHDR);
570 }
571#endif
572
573 /* Do delay if wanted. */
574 if((delayvalue = b_value("bootdelay")) != nil > 0) {
575 delay(delayvalue);
576 }
577
578 /* Run the trailer function just before starting Minix. */
579 if (!run_trailer()) { errno= 0; return; }
580
581 /* Translate the boot parameters to what Minix likes best. */
582 if (!params2params(params, sizeof(params))) { errno= 0; return; }
583
584 /* Set the video to the required mode. */
585 if ((console= b_value("console")) == nil || (mode= a2x(console)) == 0) {
586 mode= strcmp(b_value("chrome"), "color") == 0 ? COLOR_MODE :
587 MONO_MODE;
588 }
589 set_mode(mode);
590
591 /* Close the disk. */
592 (void) dev_close();
593
594 /* Minix. */
595 minix(process[KERNEL].entry, process[KERNEL].cs,
596 process[KERNEL].ds, params, sizeof(params), aout);
597
598 if (!(k_flags & K_BRET)) {
599 extern u32_t reboot_code;
600 raw_copy(mon2abs(params), reboot_code, sizeof(params));
601 }
602 parse_code(params);
603
604 /* Return from Minix. Things may have changed, so assume nothing. */
605 fsok= -1;
606 errno= 0;
607
608 /* Read leftover character, if any. */
609 scan_keyboard();
610}
611
612ino_t latest_version(char *version, struct stat *stp)
613/* Recursively read the current directory, selecting the newest image on
614 * the way up. (One can't use r_stat while reading a directory.)
615 */
616{
617 char name[NAME_MAX + 1];
618 ino_t ino, newest;
619 time_t mtime;
620
621 if ((ino= r_readdir(name)) == 0) { stp->st_mtime= 0; return 0; }
622
623 newest= latest_version(version, stp);
624 mtime= stp->st_mtime;
625 r_stat(ino, stp);
626
627 if (S_ISREG(stp->st_mode) && stp->st_mtime > mtime) {
628 newest= ino;
629 strcpy(version, name);
630 } else {
631 stp->st_mtime= mtime;
632 }
633 return newest;
634}
635
636char *select_image(char *image)
637/* Look image up on the filesystem, if it is a file then we're done, but
638 * if its a directory then we want the newest file in that directory. If
639 * it doesn't exist at all, then see if it is 'number:number' and get the
640 * image from that absolute offset off the disk.
641 */
642{
643 ino_t image_ino;
644 struct stat st;
645
646 image= strcpy(malloc((strlen(image) + 1 + NAME_MAX + 1)
647 * sizeof(char)), image);
648
649 fsok= r_super(&block_size) != 0;
650 if (!fsok || (image_ino= r_lookup(ROOT_INO, image)) == 0) {
651 char *size;
652
653 if (numprefix(image, &size) && *size++ == ':'
654 && numeric(size)) {
655 vir2sec= flat_vir2sec;
656 image_off= a2l(image);
657 image_size= a2l(size);
658 strcpy(image, "Minix");
659 return image;
660 }
661 if (!fsok)
662 printf("No image selected\n");
663 else
664 printf("Can't load %s: %s\n", image, unix_err(errno));
665 goto bail_out;
666 }
667
668 r_stat(image_ino, &st);
669 if (!S_ISREG(st.st_mode)) {
670 char *version= image + strlen(image);
671 char dots[NAME_MAX + 1];
672
673 if (!S_ISDIR(st.st_mode)) {
674 printf("%s: %s\n", image, unix_err(ENOTDIR));
675 goto bail_out;
676 }
677 (void) r_readdir(dots);
678 (void) r_readdir(dots); /* "." & ".." */
679 *version++= '/';
680 *version= 0;
681 if ((image_ino= latest_version(version, &st)) == 0) {
682 printf("There are no images in %s\n", image);
683 goto bail_out;
684 }
685 r_stat(image_ino, &st);
686 }
687 vir2sec= file_vir2sec;
688 image_size= (st.st_size + SECTOR_SIZE - 1) >> SECTOR_SHIFT;
689 return image;
690bail_out:
691 free(image);
692 return nil;
693}
694
695void bootminix(void)
696/* Load Minix and run it. (Given the size of this program it is surprising
697 * that it ever gets to that.)
698 */
699{
700 char *image;
701
702 if ((image= select_image(b_value("image"))) == nil) return;
703
704 exec_image(image);
705
706 switch (errno) {
707 case ENOEXEC:
708 printf("%s contains a bad program header\n", image);
709 break;
710 case ENOMEM:
711 printf("Not enough memory to load %s\n", image);
712 break;
713 case EIO:
714 printf("Unsuspected EOF on %s\n", image);
715 case 0:
716 /* No error or error already reported. */;
717 }
718 free(image);
719}
720
721/*
722 * $PchId: bootimage.c,v 1.10 2002/02/27 19:39:09 philip Exp $
723 */
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