1 #ident "$Id: setup.c,v 1.50 2005/04/29 06:04:45 hpa Exp $"
2 /* ----------------------------------------------------------------------- *
4 * Copyright 2001-2004 H. Peter Anvin - All Rights Reserved
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, Inc., 53 Temple Place Ste 330,
9 * Boston MA 02111-1307, USA; either version 2 of the License, or
10 * (at your option) any later version; incorporated herein by reference.
12 * ----------------------------------------------------------------------- */
20 const char memdisk_version[] =
21 "MEMDISK " VERSION " " DATE;
22 const char copyright[] =
23 "Copyright " FIRSTYEAR "-" COPYYEAR " H. Peter Anvin";
25 extern const char _binary_memdisk_bin_start[], _binary_memdisk_bin_end[];
26 extern const char _binary_memdisk_bin_size[]; /* Weird, I know */
28 struct memdisk_header {
35 /* The Disk Parameter Table may be required */
38 uint16_t max_cyl; /* Max cylinder */
39 uint8_t max_head; /* Max head */
40 uint8_t junk1[5]; /* Obsolete junk, leave at zero */
41 uint8_t ctrl; /* Control byte */
42 uint8_t junk2[7]; /* More obsolete junk */
45 uint8_t specify1; /* "First specify byte" */
46 uint8_t specify2; /* "Second specify byte" */
47 uint8_t delay; /* Delay until motor turn off */
48 uint8_t sectors; /* Sectors/track */
50 uint8_t bps; /* Bytes/sector (02h = 512) */
51 uint8_t isgap; /* Length of intersector gap */
52 uint8_t dlen; /* Data length (0FFh) */
53 uint8_t fgap; /* Formatting gap */
55 uint8_t ffill; /* Format fill byte */
56 uint8_t settle; /* Head settle time (ms) */
57 uint8_t mstart; /* Motor start time */
58 uint8_t _pad1; /* Padding */
60 uint32_t old_fd_dpt; /* Extension: pointer to old INT 1Eh */
67 uint16_t cmdline_off, cmdline_seg;
89 #define CONFIG_READONLY 0x01
90 #define CONFIG_RAW 0x02
91 #define CONFIG_BIGRAW 0x08 /* MUST be 8! */
99 /* This is the header in the boot sector/setup area */
100 struct setup_header {
112 uint32_t realmode_swtch;
114 uint8_t type_of_loader;
116 uint16_t setup_move_size;
117 uint32_t code32_start;
118 uint32_t ramdisk_image;
119 uint32_t ramdisk_size;
120 uint32_t bootsect_kludge;
121 uint16_t head_end_ptr;
123 uint32_t cmd_line_ptr;
124 uint32_t initrd_addr_max;
127 const struct setup_header * const shdr = (struct setup_header *)(LOW_SEG << 4);
129 /* Access to high memory */
131 /* Access to objects in the zero page */
133 wrz_8(uint32_t addr, uint8_t data)
135 *((uint8_t *)addr) = data;
138 wrz_16(uint32_t addr, uint16_t data)
140 *((uint16_t *)addr) = data;
143 wrz_32(uint32_t addr, uint32_t data)
145 *((uint32_t *)addr) = data;
147 static inline uint8_t
150 return *((uint8_t *)addr);
152 static inline uint16_t
153 rdz_16(uint32_t addr)
155 return *((uint16_t *)addr);
157 static inline uint32_t
158 rdz_32(uint32_t addr)
160 return *((uint32_t *)addr);
163 /* Addresses in the zero page */
164 #define BIOS_INT13 (0x13*4) /* INT 13h vector */
165 #define BIOS_INT15 (0x15*4) /* INT 15h vector */
166 #define BIOS_INT1E (0x1E*4) /* INT 1Eh vector */
167 #define BIOS_INT40 (0x40*4) /* INT 13h vector */
168 #define BIOS_INT41 (0x41*4) /* INT 41h vector */
169 #define BIOS_INT46 (0x46*4) /* INT 46h vector */
170 #define BIOS_BASEMEM 0x413 /* Amount of DOS memory */
171 #define BIOS_EQUIP 0x410 /* BIOS equipment list */
172 #define BIOS_HD_COUNT 0x475 /* Number of hard drives present */
175 * Routine to seek for a command-line item and return a pointer
176 * to the data portion, if present
179 /* Magic return values */
180 #define CMD_NOTFOUND ((char *)-1) /* Not found */
181 #define CMD_BOOL ((char *)-2) /* Found boolean option */
182 #define CMD_HASDATA(X) ((int)(X) >= 0)
184 const char *getcmditem(const char *what)
187 const char *wp = what;
190 for ( p = shdr->cmdline ; *p ; p++ ) {
192 case 0: /* Ground state */
200 case 1: /* Matching */
204 else if ( *p == ' ' )
215 case 2: /* Mismatch, skip rest of option */
217 match = 0; /* Next option */
222 /* Check for matching string at end of line */
223 if ( match == 1 && *wp == '\0' )
230 * Check to see if this is a gzip image
232 #define UNZIP_ALIGN 512
234 extern void _end; /* Symbol signalling end of data */
236 void unzip_if_needed(uint32_t *where_p, uint32_t *size_p)
238 uint32_t where = *where_p;
239 uint32_t size = *size_p;
241 uint32_t startrange, endrange;
242 uint32_t gzdatasize, gzwhere;
243 uint32_t orig_crc, offset;
247 /* Is it a gzip image? */
248 if (check_zip ((void *)where, size, &zbytes, &gzdatasize,
249 &orig_crc, &offset) == 0) {
251 if (offset + zbytes > size) {
252 /* Assertion failure; check_zip is supposed to guarantee this
254 puts("internal error: check_zip returned nonsense\n");
258 /* Find a good place to put it: search memory ranges in descending order
259 until we find one that is legal and fits */
261 for ( i = nranges-1 ; i >= 0 ; i-- ) {
262 /* We can't use > 4G memory (32 bits only.) Truncate to 2^32-1
263 so we don't have to deal with funny wraparound issues. */
266 if ( ranges[i].type != 1 )
270 if ( ranges[i].start >= 0xFFFFFFFF )
272 startrange = (uint32_t)ranges[i].start;
274 /* Range end (0 for end means 2^64) */
275 endrange = ((ranges[i+1].start >= 0xFFFFFFFF ||
276 ranges[i+1].start == 0)
277 ? 0xFFFFFFFF : (uint32_t)ranges[i+1].start);
279 /* Make sure we don't overwrite ourselves */
280 if ( startrange < (uint32_t)&_end )
281 startrange = (uint32_t)&_end;
283 /* Allow for alignment */
284 startrange = (ranges[i].start + (UNZIP_ALIGN-1)) & ~(UNZIP_ALIGN-1);
286 /* In case we just killed the whole range... */
287 if ( startrange >= endrange )
290 /* Must be large enough... don't rely on gzwhere for this (wraparound) */
291 if ( endrange-startrange < gzdatasize )
294 /* This is where the gz image should be put if we put it in this range */
295 gzwhere = (endrange - gzdatasize) & ~(UNZIP_ALIGN-1);
297 /* Cast to uint64_t just in case we're flush with the top byte */
298 if ( (uint64_t)where+size >= gzwhere && where < endrange ) {
299 /* Need to move source data to avoid compressed/uncompressed overlap */
302 if ( gzwhere-startrange < size )
303 continue; /* Can't fit both old and new */
305 newwhere = (gzwhere - size) & ~(UNZIP_ALIGN-1);
306 printf("Moving compressed data from 0x%08x to 0x%08x\n",
309 /* Our memcpy() is OK, because we always move from a higher
310 address to a lower one */
311 memcpy((void *)newwhere, (void *)where, size);
321 printf("Not enough memory to decompress image (need 0x%08x bytes)\n",
326 printf("gzip image: decompressed addr 0x%08x, len 0x%08x: ",
329 *size_p = gzdatasize;
330 *where_p = (uint32_t)unzip((void *)(where + offset), zbytes,
331 gzdatasize, orig_crc, (void *)target);
336 * Figure out the "geometry" of the disk in question
339 uint32_t sectors; /* 512-byte sector count */
340 uint32_t c, h, s; /* C/H/S geometry */
341 uint32_t offset; /* Byte offset for disk */
342 uint8_t type; /* Type byte for INT 13h AH=08h */
343 uint8_t driveno; /* Drive no */
346 static const struct geometry geometries[] =
348 { 360*2, 40, 2, 9, 0, 0x01, 0 }, /* 360 K */
349 { 720*2, 80, 2, 9, 0, 0x03, 0 }, /* 720 K*/
350 { 1200*2, 80, 2, 15, 0, 0x02, 0 }, /* 1200 K */
351 { 1440*2, 80, 2, 18, 0, 0x04, 0 }, /* 1440 K */
352 { 1680*2, 80, 2, 21, 0, 0x04, 0 }, /* 1680 K */
353 { 1722*2, 82, 2, 21, 0, 0x04, 0 }, /* 1722 K */
354 { 2880*2, 80, 2, 36, 0, 0x06, 0 }, /* 2880 K */
355 { 3840*2, 80, 2, 48, 0, 0x06, 0 }, /* 3840 K */
357 #define known_geometries (sizeof(geometries)/sizeof(struct geometry))
359 /* Format of a DOS partition table entry */
362 uint8_t start_h, start_s, start_c;
364 uint8_t end_h, end_s, end_c;
369 /* Format of a DOSEMU header */
370 struct dosemu_header {
371 uint8_t magic[7]; /* DOSEMU\0 */
377 } __attribute__((packed));
379 #define FOUR(a,b,c,d) (((a) << 24)|((b) << 16)|((c) << 8)|(d))
381 const struct geometry *get_disk_image_geometry(uint32_t where, uint32_t size)
383 static struct geometry hd_geometry = { 0, 0, 0, 0, 0, 0, 0x80 };
384 struct ptab_entry ptab[4]; /* Partition table buffer */
385 struct dosemu_header dosemu;
386 unsigned int sectors, v;
387 unsigned int max_c, max_h, max_s;
388 unsigned int c, h, s, offset;
393 printf("command line: %s\n", shdr->cmdline);
396 if ( CMD_HASDATA(p = getcmditem("offset")) && (v = atou(p)) )
399 sectors = (size-offset) >> 9;
400 for ( i = 0 ; i < known_geometries ; i++ ) {
401 if ( sectors == geometries[i].sectors ) {
402 hd_geometry = geometries[i];
407 hd_geometry.sectors = sectors;
408 hd_geometry.offset = offset;
410 /* Do we have a DOSEMU header? */
411 memcpy(&dosemu, (char *)where+hd_geometry.offset, sizeof dosemu);
412 if ( !memcmp("DOSEMU", dosemu.magic, 7) ) {
413 /* Always a hard disk unless overruled by command-line options */
414 hd_geometry.driveno = 0x80;
415 hd_geometry.type = 0;
416 hd_geometry.c = dosemu.c;
417 hd_geometry.h = dosemu.h;
418 hd_geometry.s = dosemu.s;
419 hd_geometry.offset += dosemu.offset;
420 sectors = (size-hd_geometry.offset) >> 9;
423 if ( CMD_HASDATA(p = getcmditem("c")) && (v = atou(p)) )
425 if ( CMD_HASDATA(p = getcmditem("h")) && (v = atou(p)) )
427 if ( CMD_HASDATA(p = getcmditem("s")) && (v = atou(p)) )
430 if ( getcmditem("floppy") != CMD_NOTFOUND ) {
431 hd_geometry.driveno = 0;
432 if ( hd_geometry.type == 0 )
433 hd_geometry.type = 0x10; /* ATAPI floppy, e.g. LS-120 */
435 } else if ( getcmditem("harddisk") != CMD_NOTFOUND ) {
436 hd_geometry.driveno = 0x80;
437 hd_geometry.type = 0;
441 if ( (hd_geometry.c == 0) || (hd_geometry.h == 0) ||
442 (hd_geometry.s == 0) ) {
443 /* Hard disk image, need to examine the partition table for geometry */
444 memcpy(&ptab, (char *)where+hd_geometry.offset+(512-2-4*16), sizeof ptab);
446 max_c = max_h = 0; max_s = 1;
447 for ( i = 0 ; i < 4 ; i++ ) {
448 if ( ptab[i].type ) {
449 c = ptab[i].start_c + (ptab[i].start_s >> 6);
450 s = (ptab[i].start_s & 0x3f);
453 if ( max_c < c ) max_c = c;
454 if ( max_h < h ) max_h = h;
455 if ( max_s < s ) max_s = s;
457 c = ptab[i].end_c + (ptab[i].end_s >> 6);
458 s = (ptab[i].end_s & 0x3f);
461 if ( max_c < c ) max_c = c;
462 if ( max_h < h ) max_h = h;
463 if ( max_s < s ) max_s = s;
467 max_c++; max_h++; /* Convert to count (1-based) */
469 if ( !hd_geometry.h )
470 hd_geometry.h = max_h;
471 if ( !hd_geometry.s )
472 hd_geometry.s = max_s;
473 if ( !hd_geometry.c )
474 hd_geometry.c = sectors/(hd_geometry.h*hd_geometry.s);
477 if ( (size-hd_geometry.offset) & 0x1ff ) {
478 puts("MEMDISK: Image has fractional end sector\n");
480 if ( sectors % (hd_geometry.h*hd_geometry.s) ) {
481 puts("MEMDISK: Image seems to have fractional end cylinder\n");
483 if ( (hd_geometry.c*hd_geometry.h*hd_geometry.s) > sectors ) {
484 puts("MEMDISK: Image appears to be truncated\n");
491 * Jump here if all hope is gone...
493 void __attribute__((noreturn)) die(void)
500 #define STACK_NEEDED 512 /* Number of bytes of stack */
503 * Actual setup routine
504 * Returns the drive number (which is then passed in %dl to the
510 uint32_t setup(syscall_t cs_syscall, void *cs_bounce)
512 unsigned int bin_size = (int) &_binary_memdisk_bin_size;
513 struct memdisk_header *hptr;
514 struct patch_area *pptr;
516 uint32_t driverptr, driveraddr;
519 const struct geometry *geometry;
520 int total_size, cmdlinelen;
522 uint32_t ramdisk_image, ramdisk_size;
524 /* Set up global variables */
525 syscall = cs_syscall;
526 sys_bounce = cs_bounce;
528 /* Show signs of life */
529 printf("%s %s\n", memdisk_version, copyright);
531 if ( !shdr->ramdisk_image || !shdr->ramdisk_size ) {
532 puts("MEMDISK: No ramdisk image specified!\n");
536 ramdisk_image = shdr->ramdisk_image;
537 ramdisk_size = shdr->ramdisk_size;
539 e820map_init(); /* Initialize memory data structure */
540 get_mem(); /* Query BIOS for memory map */
541 parse_mem(); /* Parse memory map */
543 printf("Ramdisk at 0x%08x, length 0x%08x\n",
544 ramdisk_image, ramdisk_size);
546 unzip_if_needed(&ramdisk_image, &ramdisk_size);
548 geometry = get_disk_image_geometry(ramdisk_image, ramdisk_size);
550 printf("Disk is %s, %u K, C/H/S = %u/%u/%u\n",
551 geometry->driveno ? "hard disk" : "floppy",
552 geometry->sectors >> 1,
553 geometry->c, geometry->h, geometry->s);
555 /* Reserve the ramdisk memory */
556 insertrange(ramdisk_image, ramdisk_size, 2);
557 parse_mem(); /* Recompute variables */
559 /* Figure out where it needs to go */
560 hptr = (struct memdisk_header *) &_binary_memdisk_bin_start;
561 pptr = (struct patch_area *)(_binary_memdisk_bin_start + hptr->patch_offs);
563 dosmem_k = rdz_16(BIOS_BASEMEM);
564 pptr->olddosmem = dosmem_k;
565 stddosmem = dosmem_k << 10;
566 /* If INT 15 E820 and INT 12 disagree, go with the most conservative */
567 if ( stddosmem > dos_mem )
570 pptr->driveno = geometry->driveno;
571 pptr->drivetype = geometry->type;
572 pptr->cylinders = geometry->c;
573 pptr->heads = geometry->h;
574 pptr->sectors = geometry->s;
575 pptr->disksize = geometry->sectors;
576 pptr->diskbuf = ramdisk_image + geometry->offset;
577 pptr->statusptr = (geometry->driveno & 0x80) ? 0x474 : 0x441;
579 pptr->bootloaderid = shdr->type_of_loader;
581 pptr->configflags = 0;
582 /* Set config flags */
583 if ( getcmditem("ro") != CMD_NOTFOUND ) {
584 puts("Marking disk readonly\n");
585 pptr->configflags |= CONFIG_READONLY;
587 if ( getcmditem("raw") != CMD_NOTFOUND ) {
588 puts("Using raw access to high memory\n");
589 pptr->configflags |= CONFIG_RAW;
591 if ( getcmditem("bigraw") != CMD_NOTFOUND ) {
592 puts("Using raw access to high memory - assuming big real mode\n");
593 pptr->configflags |= CONFIG_BIGRAW|CONFIG_RAW;
596 /* Set up a drive parameter table */
597 if ( geometry->driveno & 0x80 ) {
599 pptr->dpt.hd.max_cyl = geometry->c-1;
600 pptr->dpt.hd.max_head = geometry->h-1;
601 pptr->dpt.hd.ctrl = (geometry->h > 8) ? 0x08: 0;
603 /* Floppy - most of these fields are bogus and mimic
604 a 1.44 MB floppy drive */
605 pptr->dpt.fd.specify1 = 0xdf;
606 pptr->dpt.fd.specify2 = 0x02;
607 pptr->dpt.fd.delay = 0x25;
608 pptr->dpt.fd.sectors = geometry->s;
609 pptr->dpt.fd.bps = 0x02;
610 pptr->dpt.fd.isgap = 0x12;
611 pptr->dpt.fd.dlen = 0xff;
612 pptr->dpt.fd.fgap = 0x6c;
613 pptr->dpt.fd.ffill = 0xf6;
614 pptr->dpt.fd.settle = 0x0f;
615 pptr->dpt.fd.mstart = 0x05;
617 pptr->dpt.fd.old_fd_dpt = rdz_32(BIOS_INT1E);
620 /* The size is given by hptr->total_size plus the size of the E820
621 map -- 12 bytes per range; we may need as many as 2 additional
622 ranges (each insertrange() can worst-case turn 1 area into 3)
623 plus the terminating range, over what nranges currently show. */
624 cmdlinelen = strlen(shdr->cmdline)+1;
625 total_size = hptr->total_size; /* Actual memdisk code */
626 total_size += (nranges+3)*sizeof(ranges[0]); /* E820 memory ranges */
627 total_size += cmdlinelen; /* Command line */
628 total_size += STACK_NEEDED; /* Stack */
629 printf("Total size needed = %u bytes, allocating %uK\n",
630 total_size, (total_size+0x3ff) >> 10);
632 if ( total_size > dos_mem ) {
633 puts("MEMDISK: Insufficient low memory\n");
637 driveraddr = stddosmem - total_size;
638 driveraddr &= ~0x3FF;
640 printf("Old dos memory at 0x%05x (map says 0x%05x), loading at 0x%05x\n",
641 stddosmem, dos_mem, driveraddr);
643 /* Reserve this range of memory */
644 wrz_16(BIOS_BASEMEM, driveraddr >> 10);
645 insertrange(driveraddr, dos_mem-driveraddr, 2);
648 pptr->mem1mb = low_mem >> 10;
649 pptr->mem16mb = high_mem >> 16;
650 if ( low_mem == (15 << 20) ) {
651 /* lowmem maxed out */
652 uint32_t int1588mem = (high_mem >> 10)+(low_mem >> 10);
653 pptr->memint1588 = (int1588mem > 0xffff) ? 0xffff : int1588mem;
655 pptr->memint1588 = low_mem >> 10;
658 printf("1588: 0x%04x 15E801: 0x%04x 0x%04x\n",
659 pptr->memint1588, pptr->mem1mb, pptr->mem16mb);
661 driverseg = driveraddr >> 4;
662 driverptr = driverseg << 16;
664 /* Anything beyond the end is for the stack */
665 pptr->mystack = (uint16_t)(stddosmem-driveraddr);
667 pptr->oldint13 = rdz_32(BIOS_INT13);
668 pptr->oldint15 = rdz_32(BIOS_INT15);
670 /* Adjust the E820 table: if there are null ranges (type 0)
671 at the end, change them to type end of list (-1).
672 This is necessary for the driver to be able to report end
673 of list correctly. */
674 while ( nranges && ranges[nranges-1].type == 0 ) {
675 ranges[--nranges].type = -1;
678 /* Query drive parameters of this type */
679 memset(®s, 0, sizeof regs);
681 regs.eax.b[1] = 0x08;
682 regs.edx.b[0] = geometry->driveno;
683 syscall(0x13, ®s, ®s);
685 if ( regs.eflags.l & 1 ) {
686 printf("INT 13 08: Failure, assuming this is the only drive\n");
689 printf("INT 13 08: Success, count = %u, BPT = %04x:%04x\n",
690 regs.edx.b[0], regs.es, regs.edi.w[0]);
691 pptr->drivecnt = regs.edx.b[0]+1;
694 /* Pointer to the command line */
695 pptr->cmdline_off = bin_size + (nranges+1)*sizeof(ranges[0]);
696 pptr->cmdline_seg = driverseg;
698 /* Copy driver followed by E820 table followed by command line */
700 unsigned char *dpp = (unsigned char *)(driverseg << 4);
701 dpp = memcpy_endptr(dpp, &_binary_memdisk_bin_start, bin_size);
702 dpp = memcpy_endptr(dpp, ranges, (nranges+1)*sizeof(ranges[0]));
703 dpp = memcpy_endptr(dpp, shdr->cmdline, cmdlinelen+1);
706 /* Install the interrupt handlers */
707 printf("old: int13 = %08x int15 = %08x\n",
708 rdz_32(BIOS_INT13), rdz_32(BIOS_INT15));
710 wrz_32(BIOS_INT13, driverptr+hptr->int13_offs);
711 wrz_32(BIOS_INT15, driverptr+hptr->int15_offs);
713 printf("new: int13 = %08x int15 = %08x\n",
714 rdz_32(BIOS_INT13), rdz_32(BIOS_INT15));
716 /* Update various BIOS magic data areas (gotta love this shit) */
718 if ( geometry->driveno & 0x80 ) {
719 /* Update BIOS hard disk count */
720 wrz_8(BIOS_HD_COUNT, rdz_8(BIOS_HD_COUNT)+1);
722 /* Update BIOS floppy disk count */
723 uint8_t equip = rdz_8(BIOS_EQUIP);
725 if ( (equip & (3 << 6)) != (3 << 6) ) {
732 wrz_8(BIOS_EQUIP, equip);
735 /* Reboot into the new "disk"; this is also a test for the interrupt hooks */
736 puts("Loading boot sector... ");
738 memset(®s, 0, sizeof regs);
740 regs.eax.w[0] = 0x0201; /* Read sector */
741 regs.ebx.w[0] = 0x7c00; /* 0000:7C00 */
742 regs.ecx.w[0] = 1; /* One sector */
743 regs.edx.w[0] = geometry->driveno;
744 syscall(0x13, ®s, ®s);
746 if ( regs.eflags.l & 1 ) {
747 puts("MEMDISK: Failed to load new boot sector\n");
751 if ( getcmditem("pause") != CMD_NOTFOUND ) {
752 puts("press any key to boot... ");
754 syscall(0x16, ®s, NULL);
757 puts("booting...\n");
759 /* On return the assembly code will jump to the boot vector */
760 return geometry->driveno;