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authorH. Peter Anvin <hpa@zytor.com>2009-05-14 16:33:37 -0700
committerH. Peter Anvin <hpa@zytor.com>2009-05-14 16:33:37 -0700
commit0046660e3849bef9d922ba69d07c5bc639d1d133 (patch)
tree0d60efb691e622912682b7bab367a51ce8ead76e /extlinux
parent1c7146a2eeaaf0021cc15e682e12609a652ed870 (diff)
downloadsyslinux-0046660e3849bef9d922ba69d07c5bc639d1d133.tar.gz
syslinux-0046660e3849bef9d922ba69d07c5bc639d1d133.tar.xz
syslinux-0046660e3849bef9d922ba69d07c5bc639d1d133.zip
core: handle more than 32K of code for disk-based derivatives
Handle more than 32K worth of code for disk-based derivatives. We do this by allowing the sector pointers to overflow past sector 1; this is OK because we limit a run to be based on only the pointers that we have read so far. XXX: This is implemented for EXTLINUX, but breaks SYSLINUX. Need to update (and unify!) the SYSLINUX installers to cope. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'extlinux')
-rw-r--r--extlinux/main.c125
1 files changed, 44 insertions, 81 deletions
diff --git a/extlinux/main.c b/extlinux/main.c
index e9226fce..c4ccd538 100644
--- a/extlinux/main.c
+++ b/extlinux/main.c
@@ -1,6 +1,7 @@
/* ----------------------------------------------------------------------- *
*
* Copyright 1998-2008 H. Peter Anvin - All Rights Reserved
+ * Copyright 2009 Intel Corporation; author: H. Peter Anvin
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -63,12 +64,14 @@ struct my_options {
unsigned int sectors;
unsigned int heads;
int raid_mode;
+ int stupid_mode;
int reset_adv;
const char *set_once;
} opt = {
.sectors = 0,
.heads = 0,
.raid_mode = 0,
+ .stupid_mode = 0,
.reset_adv = 0,
.set_once = NULL,
};
@@ -82,6 +85,7 @@ static void __attribute__((noreturn)) usage(int rv)
" --zip -z Force zipdrive geometry (-H 64 -S 32)\n"
" --sectors=# -S Force the number of sectors per track\n"
" --heads=# -H Force number of heads\n"
+ " --stupid -s Slow, safe and stupid mode\n"
" --raid -r Fall back to the next device on boot failure\n"
" --once=... -o Execute a command once upon boot\n"
" --clear-once -O Clear the boot-once command\n"
@@ -109,6 +113,7 @@ static const struct option long_options[] = {
{ "update", 0, NULL, 'U' },
{ "zipdrive", 0, NULL, 'z' },
{ "sectors", 1, NULL, 'S' },
+ { "stupid", 0, NULL, 's' },
{ "heads", 1, NULL, 'H' },
{ "raid-mode", 0, NULL, 'r' },
{ "version", 0, NULL, 'v' },
@@ -126,57 +131,6 @@ static const char short_options[] = "iUuzS:H:rvho:O";
# define BLKGETSIZE64 _IOR(0x12,114,size_t)
#endif
-#define LDLINUX_MAGIC 0x3eb202fe
-
-enum bs_offsets {
- bsJump = 0x00,
- bsOemName = 0x03,
- bsBytesPerSec = 0x0b,
- bsSecPerClust = 0x0d,
- bsResSectors = 0x0e,
- bsFATs = 0x10,
- bsRootDirEnts = 0x11,
- bsSectors = 0x13,
- bsMedia = 0x15,
- bsFATsecs = 0x16,
- bsSecPerTrack = 0x18,
- bsHeads = 0x1a,
- bsHiddenSecs = 0x1c,
- bsHugeSectors = 0x20,
-
- /* FAT12/16 only */
- bs16DriveNumber = 0x24,
- bs16Reserved1 = 0x25,
- bs16BootSignature = 0x26,
- bs16VolumeID = 0x27,
- bs16VolumeLabel = 0x2b,
- bs16FileSysType = 0x36,
- bs16Code = 0x3e,
-
- /* FAT32 only */
- bs32FATSz32 = 36,
- bs32ExtFlags = 40,
- bs32FSVer = 42,
- bs32RootClus = 44,
- bs32FSInfo = 48,
- bs32BkBootSec = 50,
- bs32Reserved = 52,
- bs32DriveNumber = 64,
- bs32Reserved1 = 65,
- bs32BootSignature = 66,
- bs32VolumeID = 67,
- bs32VolumeLabel = 71,
- bs32FileSysType = 82,
- bs32Code = 90,
-
- bsSignature = 0x1fe
-};
-
-#define bsHead bsJump
-#define bsHeadLen (bsOemName-bsHead)
-#define bsCode bs32Code /* The common safe choice */
-#define bsCodeLen (bsSignature-bs32Code)
-
#ifndef EXT2_SUPER_OFFSET
#define EXT2_SUPER_OFFSET 1024
#endif
@@ -406,8 +360,10 @@ patch_file_and_bootblock(int fd, int dirfd, int devfd)
uint32_t *sectp;
uint64_t totalbytes, totalsectors;
int nsect;
- unsigned char *p, *patcharea;
- int i, dw;
+ uint32_t *wp;
+ struct boot_sector *bs;
+ struct patch_area *patcharea;
+ int i, dw, nptrs;
uint32_t csum;
if ( fstat(dirfd, &dirst) ) {
@@ -428,26 +384,28 @@ patch_file_and_bootblock(int fd, int dirfd, int devfd)
early bootstrap share code with the FAT version. */
dprintf("heads = %u, sect = %u\n", geo.heads, geo.sectors);
+ bs = (struct boot_sector *)boot_block;
+
totalsectors = totalbytes >> SECTOR_SHIFT;
if ( totalsectors >= 65536 ) {
- set_16(boot_block+bsSectors, 0);
+ set_16(&bs->bsSectors, 0);
} else {
- set_16(boot_block+bsSectors, totalsectors);
+ set_16(&bs->bsSectors, totalsectors);
}
- set_32(boot_block+bsHugeSectors, totalsectors);
+ set_32(&bs->bsHugeSectors, totalsectors);
- set_16(boot_block+bsBytesPerSec, SECTOR_SIZE);
- set_16(boot_block+bsSecPerTrack, geo.sectors);
- set_16(boot_block+bsHeads, geo.heads);
- set_32(boot_block+bsHiddenSecs, geo.start);
+ set_16(&bs->bsBytesPerSec, SECTOR_SIZE);
+ set_16(&bs->bsSecPerTrack, geo.sectors);
+ set_16(&bs->bsHeads, geo.heads);
+ set_32(&bs->bsHiddenSecs, geo.start);
/* If we're in RAID mode then patch the appropriate instruction;
either way write the proper boot signature */
- i = get_16(boot_block+0x1FE);
+ i = get_16(&bs->bsSignature);
if (opt.raid_mode)
- set_16(boot_block+i, 0x18CD); /* INT 18h */
+ set_16((uint16_t *)(boot_block+i), 0x18CD); /* INT 18h */
- set_16(boot_block+0x1FE, 0xAA55);
+ set_16(&bs->bsSignature, 0xAA55);
/* Construct the boot file */
@@ -461,37 +419,39 @@ patch_file_and_bootblock(int fd, int dirfd, int devfd)
}
/* First sector need pointer in boot sector */
- set_32(boot_block+0x1F8, *sectp++);
- nsect--;
+ set_32(&bs->NextSector, *sectp++);
+
+ /* Stupid mode? */
+ if (opt.stupid_mode)
+ set_16(&bs->MaxTransfer, 1);
/* Search for LDLINUX_MAGIC to find the patch area */
- for ( p = boot_image ; get_32(p) != LDLINUX_MAGIC ; p += 4 );
- patcharea = p+8;
+ for (wp = (uint32_t *)boot_image; get_32(wp) != LDLINUX_MAGIC; wp++);
+ patcharea = (struct patch_area *)wp;
/* Set up the totals */
dw = boot_image_len >> 2; /* COMPLETE dwords, excluding ADV */
- set_16(patcharea, dw);
- set_16(patcharea+2, nsect); /* Not including the first sector, but
- including the ADV */
- set_32(patcharea+8, dirst.st_ino); /* "Current" directory */
+ set_16(&patcharea->data_sectors, nsect-2); /* -2 for the ADVs */
+ set_16(&patcharea->adv_sectors, 2);
+ set_32(&patcharea->dwords, dw);
+ set_32(&patcharea->currentdir, dirst.st_ino);
/* Set the sector pointers */
- p = patcharea+12;
+ wp = (uint32_t *)((char *)boot_image+get_16(&patcharea->secptroffset));
+ nptrs = get_16(&patcharea->secptrcnt);
- memset(p, 0, 64*4);
- while ( nsect-- ) {
- set_32(p, *sectp++);
- p += 4;
- }
+ memset(wp, 0, nptrs*4);
+ while ( nsect-- )
+ set_32(wp++, *sectp++);
/* Now produce a checksum */
- set_32(patcharea+4, 0);
+ set_32(&patcharea->checksum, 0);
csum = LDLINUX_MAGIC;
- for ( i = 0, p = boot_image ; i < dw ; i++, p += 4 )
- csum -= get_32(p); /* Negative checksum */
+ for (i = 0, wp = (uint32_t *)boot_image; i < dw; i++, wp++)
+ csum -= get_32(wp); /* Negative checksum */
- set_32(patcharea+4, csum);
+ set_32(&patcharea->checksum, csum);
}
/*
@@ -981,6 +941,9 @@ main(int argc, char *argv[])
case 'r':
opt.raid_mode = 1;
break;
+ case 's':
+ opt.stupid_mode = 1;
+ break;
case 'i':
update_only = 0;
break;