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diff --git a/com32/modules/chain.c b/com32/modules/chain.c
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-/* ----------------------------------------------------------------------- *
- *
- * Copyright 2003-2009 H. Peter Anvin - All Rights Reserved
- * Copyright 2009-2011 Intel Corporation; author: H. Peter Anvin
- * Significant portions copyright (C) 2010 Shao Miller
- * [partition iteration, GPT, "fs"]
- *
- * 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
- * the Free Software Foundation, Inc., 53 Temple Place Ste 330,
- * Boston MA 02111-1307, USA; either version 2 of the License, or
- * (at your option) any later version; incorporated herein by reference.
- *
- * ----------------------------------------------------------------------- */
-
-/*
- * chain.c
- *
- * Chainload a hard disk (currently rather braindead.)
- *
- * Usage: chain [options]
- * chain hd<disk#> [<partition>] [options]
- * chain fd<disk#> [options]
- * chain mbr:<id> [<partition>] [options]
- * chain guid:<guid> [<partition>] [options]
- * chain label:<label> [<partition>] [options]
- * chain boot [<partition>] [options]
- *
- * For example, "chain msdos=io.sys" will load DOS from the current Syslinux
- * filesystem. "chain hd0 1" will boot the first partition on the first hard
- * disk.
- *
- * When none of the "hdX", "fdX", "mbr:", "guid:", "label:", "boot" or "fs"
- * options are specified, the default behaviour is equivalent to "boot".
- * "boot" means to use the current Syslinux drive, and you can also specify
- * a partition.
- *
- * The mbr: syntax means search all the hard disks until one with a
- * specific MBR serial number (bytes 440-443) is found.
- *
- * Partitions 1-4 are primary, 5+ logical, 0 = boot MBR (default.)
- *
- * "fs" will use the current Syslinux filesystem as the boot drive/partition.
- * When booting from PXELINUX, you will most likely wish to specify a disk.
- *
- * Options:
- *
- * file=<loader>
- * loads the file <loader> **from the Syslinux filesystem**
- * instead of loading the boot sector.
- *
- * seg=<segment>
- * loads at and jumps to <seg>:0000 instead of 0000:7C00.
- *
- * isolinux=<loader>
- * chainload another version/build of the ISOLINUX bootloader and patch
- * the loader with appropriate parameters in memory.
- * This avoids the need for the -eltorito-alt-boot parameter of mkisofs,
- * when you want more than one ISOLINUX per CD/DVD.
- *
- * ntldr=<loader>
- * equivalent to seg=0x2000 file=<loader> sethidden,
- * used with WinNT's loaders
- *
- * cmldr=<loader>
- * used with Recovery Console of Windows NT/2K/XP.
- * same as ntldr=<loader> & "cmdcons\0" written to
- * the system name field in the bootsector
- *
- * freedos=<loader>
- * equivalent to seg=0x60 file=<loader> sethidden,
- * used with FreeDOS' kernel.sys.
- *
- * msdos=<loader>
- * pcdos=<loader>
- * equivalent to seg=0x70 file=<loader> sethidden,
- * used with DOS' io.sys.
- *
- * drmk=<loader>
- * Similar to msdos=<loader> but prepares the special options
- * for the Dell Real Mode Kernel.
- *
- * grub=<loader>
- * same as seg=0x800 file=<loader> & jumping to seg 0x820,
- * used with GRUB Legacy stage2 files.
- *
- * grubcfg=<filename>
- * set an alternative config filename in stage2 of Grub Legacy,
- * only applicable in combination with "grub=<loader>".
- *
- * grldr=<loader>
- * pass the partition number to GRUB4DOS,
- * used with GRUB4DOS' grldr.
- *
- * swap
- * if the disk is not fd0/hd0, install a BIOS stub which swaps
- * the drive numbers.
- *
- * hide
- * change type of primary partitions with IDs 01, 04, 06, 07,
- * 0b, 0c, or 0e to 1x, except for the selected partition, which
- * is converted the other way.
- *
- * sethidden
- * update the "hidden sectors" (partition offset) field in a
- * FAT/NTFS boot sector.
- *
- * keeppxe
- * keep the PXE and UNDI stacks in memory (PXELINUX only).
- */
-
-#include <com32.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <ctype.h>
-#include <string.h>
-#include <console.h>
-#include <minmax.h>
-#include <stdbool.h>
-#include <dprintf.h>
-#include <syslinux/loadfile.h>
-#include <syslinux/bootrm.h>
-#include <syslinux/config.h>
-#include <syslinux/video.h>
-
-#define SECTOR 512 /* bytes/sector */
-
-static struct options {
- const char *loadfile;
- uint16_t keeppxe;
- uint16_t seg;
- bool isolinux;
- bool cmldr;
- bool grub;
- bool grldr;
- const char *grubcfg;
- bool swap;
- bool hide;
- bool sethidden;
- bool drmk;
-} opt;
-
-struct data_area {
- void *data;
- addr_t base;
- addr_t size;
-};
-
-static inline void error(const char *msg)
-{
- fputs(msg, stderr);
-}
-
-/*
- * Call int 13h, but with retry on failure. Especially floppies need this.
- */
-static int int13_retry(const com32sys_t * inreg, com32sys_t * outreg)
-{
- int retry = 6; /* Number of retries */
- com32sys_t tmpregs;
-
- if (!outreg)
- outreg = &tmpregs;
-
- while (retry--) {
- __intcall(0x13, inreg, outreg);
- if (!(outreg->eflags.l & EFLAGS_CF))
- return 0; /* CF=0, OK */
- }
-
- return -1; /* Error */
-}
-
-/*
- * Query disk parameters and EBIOS availability for a particular disk.
- */
-struct diskinfo {
- int disk;
- int ebios; /* EBIOS supported on this disk */
- int cbios; /* CHS geometry is valid */
- int head;
- int sect;
-} disk_info;
-
-static int get_disk_params(int disk)
-{
- static com32sys_t getparm, parm, getebios, ebios;
-
- disk_info.disk = disk;
- disk_info.ebios = disk_info.cbios = 0;
-
- /* Get EBIOS support */
- getebios.eax.w[0] = 0x4100;
- getebios.ebx.w[0] = 0x55aa;
- getebios.edx.b[0] = disk;
- getebios.eflags.b[0] = 0x3; /* CF set */
-
- __intcall(0x13, &getebios, &ebios);
-
- if (!(ebios.eflags.l & EFLAGS_CF) &&
- ebios.ebx.w[0] == 0xaa55 && (ebios.ecx.b[0] & 1)) {
- disk_info.ebios = 1;
- }
-
- /* Get disk parameters -- really only useful for
- hard disks, but if we have a partitioned floppy
- it's actually our best chance... */
- getparm.eax.b[1] = 0x08;
- getparm.edx.b[0] = disk;
-
- __intcall(0x13, &getparm, &parm);
-
- if (parm.eflags.l & EFLAGS_CF)
- return disk_info.ebios ? 0 : -1;
-
- disk_info.head = parm.edx.b[1] + 1;
- disk_info.sect = parm.ecx.b[0] & 0x3f;
- if (disk_info.sect == 0) {
- disk_info.sect = 1;
- } else {
- disk_info.cbios = 1; /* Valid geometry */
- }
-
- return 0;
-}
-
-/*
- * Get a disk block and return a malloc'd buffer.
- * Uses the disk number and information from disk_info.
- */
-struct ebios_dapa {
- uint16_t len;
- uint16_t count;
- uint16_t off;
- uint16_t seg;
- uint64_t lba;
-};
-
-/* Read count sectors from drive, starting at lba. Return a new buffer */
-static void *read_sectors(uint64_t lba, uint8_t count)
-{
- com32sys_t inreg;
- struct ebios_dapa *dapa = __com32.cs_bounce;
- void *buf = (char *)__com32.cs_bounce + SECTOR;
- void *data;
-
- if (!count)
- /* Silly */
- return NULL;
-
- memset(&inreg, 0, sizeof inreg);
-
- if (disk_info.ebios) {
- dapa->len = sizeof(*dapa);
- dapa->count = count;
- dapa->off = OFFS(buf);
- dapa->seg = SEG(buf);
- dapa->lba = lba;
-
- inreg.esi.w[0] = OFFS(dapa);
- inreg.ds = SEG(dapa);
- inreg.edx.b[0] = disk_info.disk;
- inreg.eax.b[1] = 0x42; /* Extended read */
- } else {
- unsigned int c, h, s, t;
-
- if (!disk_info.cbios) {
- /* We failed to get the geometry */
-
- if (lba)
- return NULL; /* Can only read MBR */
-
- s = h = c = 0;
- } else {
- s = lba % disk_info.sect;
- t = lba / disk_info.sect; /* Track = head*cyl */
- h = t % disk_info.head;
- c = t / disk_info.head;
- }
-
- if (s >= 63 || h >= 256 || c >= 1024)
- return NULL;
-
- inreg.eax.b[0] = count;
- inreg.eax.b[1] = 0x02; /* Read */
- inreg.ecx.b[1] = c;
- inreg.ecx.b[0] = ((c & 0x300) >> 2) | (s+1);
- inreg.edx.b[1] = h;
- inreg.edx.b[0] = disk_info.disk;
- inreg.ebx.w[0] = OFFS(buf);
- inreg.es = SEG(buf);
- }
-
- if (int13_retry(&inreg, NULL))
- return NULL;
-
- data = malloc(count * SECTOR);
- if (data)
- memcpy(data, buf, count * SECTOR);
- return data;
-}
-
-static int write_sector(unsigned int lba, const void *data)
-{
- com32sys_t inreg;
- struct ebios_dapa *dapa = __com32.cs_bounce;
- void *buf = (char *)__com32.cs_bounce + SECTOR;
-
- memcpy(buf, data, SECTOR);
- memset(&inreg, 0, sizeof inreg);
-
- if (disk_info.ebios) {
- dapa->len = sizeof(*dapa);
- dapa->count = 1; /* 1 sector */
- dapa->off = OFFS(buf);
- dapa->seg = SEG(buf);
- dapa->lba = lba;
-
- inreg.esi.w[0] = OFFS(dapa);
- inreg.ds = SEG(dapa);
- inreg.edx.b[0] = disk_info.disk;
- inreg.eax.w[0] = 0x4300; /* Extended write */
- } else {
- unsigned int c, h, s, t;
-
- if (!disk_info.cbios) {
- /* We failed to get the geometry */
-
- if (lba)
- return -1; /* Can only write MBR */
-
- s = h = c = 0;
- } else {
- s = lba % disk_info.sect;
- t = lba / disk_info.sect; /* Track = head*cyl */
- h = t % disk_info.head;
- c = t / disk_info.head;
- }
-
- if (s >= 63 || h >= 256 || c >= 1024)
- return -1;
-
- inreg.eax.w[0] = 0x0301; /* Write one sector */
- inreg.ecx.b[1] = c;
- inreg.ecx.b[0] = ((c & 0x300) >> 2) | (s+1);
- inreg.edx.b[1] = h;
- inreg.edx.b[0] = disk_info.disk;
- inreg.ebx.w[0] = OFFS(buf);
- inreg.es = SEG(buf);
- }
-
- if (int13_retry(&inreg, NULL))
- return -1;
-
- return 0; /* ok */
-}
-
-static int write_verify_sector(unsigned int lba, const void *buf)
-{
- char *rb;
- int rv;
-
- rv = write_sector(lba, buf);
- if (rv)
- return rv; /* Write failure */
- rb = read_sectors(lba, 1);
- if (!rb)
- return -1; /* Readback failure */
- rv = memcmp(buf, rb, SECTOR);
- free(rb);
- return rv ? -1 : 0;
-}
-
-/*
- * CHS (cylinder, head, sector) value extraction macros.
- * Taken from WinVBlock. Does not expand to an lvalue
-*/
-#define chs_head(chs) chs[0]
-#define chs_sector(chs) (chs[1] & 0x3F)
-#define chs_cyl_high(chs) (((uint16_t)(chs[1] & 0xC0)) << 2)
-#define chs_cyl_low(chs) ((uint16_t)chs[2])
-#define chs_cylinder(chs) (chs_cyl_high(chs) | chs_cyl_low(chs))
-typedef uint8_t chs[3];
-
-/* A DOS partition table entry */
-struct part_entry {
- uint8_t active_flag; /* 0x80 if "active" */
- chs start;
- uint8_t ostype;
- chs end;
- uint32_t start_lba;
- uint32_t length;
-} __attribute__ ((packed));
-
-static void mbr_part_dump(const struct part_entry *part)
-{
- (void)part;
- dprintf("Partition status _____ : 0x%.2x\n"
- "Partition CHS start\n"
- " Cylinder ___________ : 0x%.4x (%u)\n"
- " Head _______________ : 0x%.2x (%u)\n"
- " Sector _____________ : 0x%.2x (%u)\n"
- "Partition type _______ : 0x%.2x\n"
- "Partition CHS end\n"
- " Cylinder ___________ : 0x%.4x (%u)\n"
- " Head _______________ : 0x%.2x (%u)\n"
- " Sector _____________ : 0x%.2x (%u)\n"
- "Partition LBA start __ : 0x%.8x (%u)\n"
- "Partition LBA count __ : 0x%.8x (%u)\n"
- "-------------------------------\n",
- part->active_flag,
- chs_cylinder(part->start),
- chs_cylinder(part->start),
- chs_head(part->start),
- chs_head(part->start),
- chs_sector(part->start),
- chs_sector(part->start),
- part->ostype,
- chs_cylinder(part->end),
- chs_cylinder(part->end),
- chs_head(part->end),
- chs_head(part->end),
- chs_sector(part->end),
- chs_sector(part->end),
- part->start_lba,
- part->start_lba,
- part->length,
- part->length);
-}
-
-/* A DOS MBR */
-struct mbr {
- char code[440];
- uint32_t disk_sig;
- char pad[2];
- struct part_entry table[4];
- uint16_t sig;
-} __attribute__ ((packed));
-static const uint16_t mbr_sig_magic = 0xAA55;
-
-/* Search for a specific drive, based on the MBR signature; bytes 440-443 */
-static int find_disk(uint32_t mbr_sig)
-{
- int drive;
- bool is_me;
- struct mbr *mbr;
-
- for (drive = 0x80; drive <= 0xff; drive++) {
- if (get_disk_params(drive))
- continue; /* Drive doesn't exist */
- if (!(mbr = read_sectors(0, 1)))
- continue; /* Cannot read sector */
- is_me = (mbr->disk_sig == mbr_sig);
- free(mbr);
- if (is_me)
- return drive;
- }
- return -1;
-}
-
-/* Forward declaration */
-struct disk_part_iter;
-
-/* Partition-/scheme-specific routine returning the next partition */
-typedef struct disk_part_iter *(*disk_part_iter_func) (struct disk_part_iter *
- part);
-
-/* Contains details for a partition under examination */
-struct disk_part_iter {
- /* The block holding the table we are part of */
- char *block;
- /* The LBA for the beginning of data */
- uint64_t lba_data;
- /* The partition number, as determined by our heuristic */
- int index;
- /* The DOS partition record to pass, if applicable */
- const struct part_entry *record;
- /* Function returning the next available partition */
- disk_part_iter_func next;
- /* Partition-/scheme-specific details */
- union {
- /* MBR specifics */
- int mbr_index;
- /* EBR specifics */
- struct {
- /* The first extended partition's start LBA */
- uint64_t lba_extended;
- /* Any applicable parent, or NULL */
- struct disk_part_iter *parent;
- /* The parent extended partition index */
- int parent_index;
- } ebr;
- /* GPT specifics */
- struct {
- /* Real (not effective) index in the partition table */
- int index;
- /* Current partition GUID */
- const struct guid *part_guid;
- /* Current partition label */
- const char *part_label;
- /* Count of entries in GPT */
- int parts;
- /* Partition record size */
- uint32_t size;
- } gpt;
- } private;
-};
-
-static struct disk_part_iter *next_ebr_part(struct disk_part_iter *part)
-{
- const struct part_entry *ebr_table;
- const struct part_entry *parent_table =
- ((const struct mbr *)part->private.ebr.parent->block)->table;
- static const struct part_entry phony = {.start_lba = 0 };
- uint64_t ebr_lba;
-
- /* Don't look for a "next EBR" the first time around */
- if (part->private.ebr.parent_index >= 0)
- /* Look at the linked list */
- ebr_table = ((const struct mbr *)part->block)->table + 1;
- /* Do we need to look for an extended partition? */
- if (part->private.ebr.parent_index < 0 || !ebr_table->start_lba) {
- /* Start looking for an extended partition in the MBR */
- while (++part->private.ebr.parent_index < 4) {
- uint8_t type = parent_table[part->private.ebr.parent_index].ostype;
-
- if ((type == 0x05) || (type == 0x0F) || (type == 0x85))
- break;
- }
- if (part->private.ebr.parent_index == 4)
- /* No extended partitions found */
- goto out_finished;
- part->private.ebr.lba_extended =
- parent_table[part->private.ebr.parent_index].start_lba;
- ebr_table = &phony;
- }
- /* Load next EBR */
- ebr_lba = ebr_table->start_lba + part->private.ebr.lba_extended;
- free(part->block);
- part->block = read_sectors(ebr_lba, 1);
- if (!part->block) {
- error("Could not load EBR!\n");
- goto err_ebr;
- }
- ebr_table = ((const struct mbr *)part->block)->table;
- dprintf("next_ebr_part:\n");
- mbr_part_dump(ebr_table);
-
- /*
- * Sanity check entry: must not extend outside the
- * extended partition. This is necessary since some OSes
- * put crap in some entries.
- */
- {
- const struct mbr *mbr =
- (const struct mbr *)part->private.ebr.parent->block;
- const struct part_entry *extended =
- mbr->table + part->private.ebr.parent_index;
-
- if (ebr_table[0].start_lba >= extended->start_lba + extended->length) {
- dprintf("Insane logical partition!\n");
- goto err_insane;
- }
- }
- /* Success */
- part->lba_data = ebr_table[0].start_lba + ebr_lba;
- dprintf("Partition %d logical lba %u\n", part->index, part->lba_data);
- part->index++;
- part->record = ebr_table;
- return part;
-
-err_insane:
-
- free(part->block);
- part->block = NULL;
-err_ebr:
-
-out_finished:
- free(part->private.ebr.parent->block);
- free(part->private.ebr.parent);
- free(part->block);
- free(part);
- return NULL;
-}
-
-static struct disk_part_iter *next_mbr_part(struct disk_part_iter *part)
-{
- struct disk_part_iter *ebr_part;
- /* Look at the partition table */
- struct part_entry *table = ((struct mbr *)part->block)->table;
-
- /* Look for data partitions */
- while (++part->private.mbr_index < 4) {
- uint8_t type = table[part->private.mbr_index].ostype;
-
- if (type == 0x00 || type == 0x05 || type == 0x0F || type == 0x85)
- /* Skip empty or extended partitions */
- continue;
- if (!table[part->private.mbr_index].length)
- /* Empty */
- continue;
- break;
- }
- /* If we're currently the last partition, it's time for EBR processing */
- if (part->private.mbr_index == 4) {
- /* Allocate another iterator for extended partitions */
- ebr_part = malloc(sizeof(*ebr_part));
- if (!ebr_part) {
- error("Could not allocate extended partition iterator!\n");
- goto err_alloc;
- }
- /* Setup EBR iterator parameters */
- ebr_part->block = NULL;
- ebr_part->index = 4;
- ebr_part->record = NULL;
- ebr_part->next = next_ebr_part;
- ebr_part->private.ebr.parent = part;
- /* Trigger an initial EBR load */
- ebr_part->private.ebr.parent_index = -1;
- /* The EBR iterator is responsible for freeing us */
- return next_ebr_part(ebr_part);
- }
- dprintf("next_mbr_part:\n");
- mbr_part_dump(table + part->private.mbr_index);
-
- /* Update parameters to reflect this new partition. Re-use iterator */
- part->lba_data = table[part->private.mbr_index].start_lba;
- dprintf("Partition %d primary lba %u\n", part->private.mbr_index, part->lba_data);
- part->index = part->private.mbr_index + 1;
- part->record = table + part->private.mbr_index;
- return part;
-
- free(ebr_part);
-err_alloc:
-
- free(part->block);
- free(part);
- return NULL;
-}
-
-/*
- * GUID
- * Be careful with endianness, you must adjust it yourself
- * iff you are directly using the fourth data chunk
- */
-struct guid {
- uint32_t data1;
- uint16_t data2;
- uint16_t data3;
- uint64_t data4;
-} __attribute__ ((packed));
-
- /*
- * This walk-map effectively reverses the little-endian
- * portions of the GUID in the output text
- */
-static const char guid_le_walk_map[] = {
- 3, -1, -1, -1, 0,
- 5, -1, 0,
- 3, -1, 0,
- 2, 1, 0,
- 1, 1, 1, 1, 1, 1
-};
-
-#if DEBUG
-/*
- * Fill a buffer with a textual GUID representation.
- * The buffer must be >= char[37] and will be populated
- * with an ASCII NUL C string terminator.
- * Example: 11111111-2222-3333-4444-444444444444
- * Endian: LLLLLLLL-LLLL-LLLL-BBBB-BBBBBBBBBBBB
- */
-static void guid_to_str(char *buf, const struct guid *id)
-{
- unsigned int i = 0;
- const char *walker = (const char *)id;
-
- while (i < sizeof(guid_le_walk_map)) {
- walker += guid_le_walk_map[i];
- if (!guid_le_walk_map[i])
- *buf = '-';
- else {
- *buf = ((*walker & 0xF0) >> 4) + '0';
- if (*buf > '9')
- *buf += 'A' - '9' - 1;
- buf++;
- *buf = (*walker & 0x0F) + '0';
- if (*buf > '9')
- *buf += 'A' - '9' - 1;
- }
- buf++;
- i++;
- }
- *buf = 0;
-}
-#endif
-
-/*
- * Create a GUID structure from a textual GUID representation.
- * The input buffer must be >= 32 hexadecimal chars and be
- * terminated with an ASCII NUL. Returns non-zero on failure.
- * Example: 11111111-2222-3333-4444-444444444444
- * Endian: LLLLLLLL-LLLL-LLLL-BBBB-BBBBBBBBBBBB
- */
-static int str_to_guid(const char *buf, struct guid *id)
-{
- char guid_seq[sizeof(struct guid) * 2];
- unsigned int i = 0;
- char *walker = (char *)id;
-
- while (*buf && i < sizeof(guid_seq)) {
- switch (*buf) {
- /* Skip these three characters */
- case '{':
- case '}':
- case '-':
- break;
- default:
- /* Copy something useful to the temp. sequence */
- if ((*buf >= '0') && (*buf <= '9'))
- guid_seq[i] = *buf - '0';
- else if ((*buf >= 'A') && (*buf <= 'F'))
- guid_seq[i] = *buf - 'A' + 10;
- else if ((*buf >= 'a') && (*buf <= 'f'))
- guid_seq[i] = *buf - 'a' + 10;
- else {
- /* Or not */
- error("Illegal character in GUID!\n");
- return -1;
- }
- i++;
- }
- buf++;
- }
- /* Check for insufficient valid characters */
- if (i < sizeof(guid_seq)) {
- error("Too few GUID characters!\n");
- return -1;
- }
- buf = guid_seq;
- i = 0;
- while (i < sizeof(guid_le_walk_map)) {
- if (!guid_le_walk_map[i])
- i++;
- walker += guid_le_walk_map[i];
- *walker = *buf << 4;
- buf++;
- *walker |= *buf;
- buf++;
- i++;
- }
- return 0;
-}
-
-/* A GPT partition */
-struct gpt_part {
- struct guid type;
- struct guid uid;
- uint64_t lba_first;
- uint64_t lba_last;
- uint64_t attribs;
- char name[72];
-} __attribute__ ((packed));
-
-static void gpt_part_dump(const struct gpt_part *gpt_part)
-{
-#ifdef DEBUG
- unsigned int i;
- char guid_text[37];
-
- dprintf("----------------------------------\n"
- "GPT part. LBA first __ : 0x%.16llx\n"
- "GPT part. LBA last ___ : 0x%.16llx\n"
- "GPT part. attribs ____ : 0x%.16llx\n"
- "GPT part. name _______ : '",
- gpt_part->lba_first, gpt_part->lba_last, gpt_part->attribs);
- for (i = 0; i < sizeof(gpt_part->name); i++) {
- if (gpt_part->name[i])
- dprintf("%c", gpt_part->name[i]);
- }
- dprintf("'");
- guid_to_str(guid_text, &gpt_part->type);
- dprintf("GPT part. type GUID __ : {%s}\n", guid_text);
- guid_to_str(guid_text, &gpt_part->uid);
- dprintf("GPT part. unique ID __ : {%s}\n", guid_text);
-#endif
- (void)gpt_part;
-}
-
-/* A GPT header */
-struct gpt {
- char sig[8];
- union {
- struct {
- uint16_t minor;
- uint16_t major;
- } fields __attribute__ ((packed));
- uint32_t uint32;
- char raw[4];
- } rev __attribute__ ((packed));
- uint32_t hdr_size;
- uint32_t chksum;
- char reserved1[4];
- uint64_t lba_cur;
- uint64_t lba_alt;
- uint64_t lba_first_usable;
- uint64_t lba_last_usable;
- struct guid disk_guid;
- uint64_t lba_table;
- uint32_t part_count;
- uint32_t part_size;
- uint32_t table_chksum;
- char reserved2[1];
-} __attribute__ ((packed));
-static const char gpt_sig_magic[] = "EFI PART";
-
-#if DEBUG
-static void gpt_dump(const struct gpt *gpt)
-{
- char guid_text[37];
-
- printf("GPT sig ______________ : '%8.8s'\n"
- "GPT major revision ___ : 0x%.4x\n"
- "GPT minor revision ___ : 0x%.4x\n"
- "GPT header size ______ : 0x%.8x\n"
- "GPT header checksum __ : 0x%.8x\n"
- "GPT reserved _________ : '%4.4s'\n"
- "GPT LBA current ______ : 0x%.16llx\n"
- "GPT LBA alternative __ : 0x%.16llx\n"
- "GPT LBA first usable _ : 0x%.16llx\n"
- "GPT LBA last usable __ : 0x%.16llx\n"
- "GPT LBA part. table __ : 0x%.16llx\n"
- "GPT partition count __ : 0x%.8x\n"
- "GPT partition size ___ : 0x%.8x\n"
- "GPT part. table chksum : 0x%.8x\n",
- gpt->sig,
- gpt->rev.fields.major,
- gpt->rev.fields.minor,
- gpt->hdr_size,
- gpt->chksum,
- gpt->reserved1,
- gpt->lba_cur,
- gpt->lba_alt,
- gpt->lba_first_usable,
- gpt->lba_last_usable,
- gpt->lba_table, gpt->part_count, gpt->part_size, gpt->table_chksum);
- guid_to_str(guid_text, &gpt->disk_guid);
- printf("GPT disk GUID ________ : {%s}\n", guid_text);
-}
-#endif
-
-static struct disk_part_iter *next_gpt_part(struct disk_part_iter *part)
-{
- const struct gpt_part *gpt_part = NULL;
-
- while (++part->private.gpt.index < part->private.gpt.parts) {
- gpt_part =
- (const struct gpt_part *)(part->block +
- (part->private.gpt.index *
- part->private.gpt.size));
- if (!gpt_part->lba_first)
- continue;
- break;
- }
- /* Were we the last partition? */
- if (part->private.gpt.index == part->private.gpt.parts) {
- goto err_last;
- }
- part->lba_data = gpt_part->lba_first;
- part->private.gpt.part_guid = &gpt_part->uid;
- part->private.gpt.part_label = gpt_part->name;
- /* Update our index */
- part->index = part->private.gpt.index + 1;
- gpt_part_dump(gpt_part);
-
- /* In a GPT scheme, we re-use the iterator */
- return part;
-
-err_last:
- free(part->block);
- free(part);
-
- return NULL;
-}
-
-static struct disk_part_iter *get_first_partition(struct disk_part_iter *part)
-{
- const struct gpt *gpt_candidate;
-
- /*
- * Ignore any passed partition iterator. The caller should
- * have passed NULL. Allocate a new partition iterator
- */
- part = malloc(sizeof(*part));
- if (!part) {
- error("Count not allocate partition iterator!\n");
- goto err_alloc_iter;
- }
- /* Read MBR */
- part->block = read_sectors(0, 2);
- if (!part->block) {
- error("Could not read two sectors!\n");
- goto err_read_mbr;
- }
- /* Check for an MBR */
- if (((struct mbr *)part->block)->sig != mbr_sig_magic) {
- error("No MBR magic!\n");
- goto err_mbr;
- }
- /* Establish a pseudo-partition for the MBR (index 0) */
- part->index = 0;
- part->record = NULL;
- part->private.mbr_index = -1;
- part->next = next_mbr_part;
- /* Check for a GPT disk */
- gpt_candidate = (const struct gpt *)(part->block + SECTOR);
- if (!memcmp(gpt_candidate->sig, gpt_sig_magic, sizeof(gpt_sig_magic))) {
- /* LBA for partition table */
- uint64_t lba_table;
-
- /* It looks like one */
- /* TODO: Check checksum. Possibly try alternative GPT */
-#if DEBUG
- puts("Looks like a GPT disk.");
- gpt_dump(gpt_candidate);
-#endif
- /* TODO: Check table checksum (maybe) */
- /* Note relevant GPT details */
- part->next = next_gpt_part;
- part->private.gpt.index = -1;
- part->private.gpt.parts = gpt_candidate->part_count;
- part->private.gpt.size = gpt_candidate->part_size;
- lba_table = gpt_candidate->lba_table;
- gpt_candidate = NULL;
- /* Load the partition table */
- free(part->block);
- part->block =
- read_sectors(lba_table,
- ((part->private.gpt.size * part->private.gpt.parts) +
- SECTOR - 1) / SECTOR);
- if (!part->block) {
- error("Could not read GPT partition list!\n");
- goto err_gpt_table;
- }
- }
- /* Return the pseudo-partition's next partition, which is real */
- return part->next(part);
-
-err_gpt_table:
-
-err_mbr:
-
- free(part->block);
- part->block = NULL;
-err_read_mbr:
-
- free(part);
-err_alloc_iter:
-
- return NULL;
-}
-
-/*
- * Search for a specific drive/partition, based on the GPT GUID.
- * We return the disk drive number if found, as well as populating the
- * boot_part pointer with the matching partition, if applicable.
- * If no matching partition is found or the GUID is a disk GUID,
- * boot_part will be populated with NULL. If not matching disk is
- * found, we return -1.
- */
-static int find_by_guid(const struct guid *gpt_guid,
- struct disk_part_iter **boot_part)
-{
- int drive;
- bool is_me;
- struct gpt *header;
-
- for (drive = 0x80; drive <= 0xff; drive++) {
- if (get_disk_params(drive))
- continue; /* Drive doesn't exist */
- if (!(header = read_sectors(1, 1)))
- continue; /* Cannot read sector */
- if (memcmp(&header->sig, gpt_sig_magic, sizeof(gpt_sig_magic))) {
- /* Not a GPT disk */
- free(header);
- continue;
- }
-#if DEBUG
- gpt_dump(header);
-#endif
- is_me = !memcmp(&header->disk_guid, gpt_guid, sizeof(*gpt_guid));
- free(header);
- if (!is_me) {
- /* Check for a matching partition */
- boot_part[0] = get_first_partition(NULL);
- while (boot_part[0]) {
- is_me =
- !memcmp(boot_part[0]->private.gpt.part_guid, gpt_guid,
- sizeof(*gpt_guid));
- if (is_me)
- break;
- boot_part[0] = boot_part[0]->next(boot_part[0]);
- }
- } else
- boot_part[0] = NULL;
- if (is_me)
- return drive;
- }
- return -1;
-}
-
-/*
- * Search for a specific partition, based on the GPT label.
- * We return the disk drive number if found, as well as populating the
- * boot_part pointer with the matching partition, if applicable.
- * If no matching partition is found, boot_part will be populated with
- * NULL and we return -1.
- */
-static int find_by_label(const char *label, struct disk_part_iter **boot_part)
-{
- int drive;
- bool is_me;
-
- for (drive = 0x80; drive <= 0xff; drive++) {
- if (get_disk_params(drive))
- continue; /* Drive doesn't exist */
- /* Check for a GPT disk */
- boot_part[0] = get_first_partition(NULL);
- if (!(boot_part[0]->next == next_gpt_part)) {
- /* Not a GPT disk */
- while (boot_part[0]) {
- /* Run through until the end */
- boot_part[0] = boot_part[0]->next(boot_part[0]);
- }
- continue;
- }
- /* Check for a matching partition */
- while (boot_part[0]) {
- char gpt_label[sizeof(((struct gpt_part *) NULL)->name)];
- const char *gpt_label_scanner =
- boot_part[0]->private.gpt.part_label;
- int j = 0;
-
- /* Re-write the GPT partition label as ASCII */
- while (gpt_label_scanner <
- boot_part[0]->private.gpt.part_label + sizeof(gpt_label)) {
- if ((gpt_label[j] = *gpt_label_scanner))
- j++;
- gpt_label_scanner++;
- }
- if ((is_me = !strcmp(label, gpt_label)))
- break;
- boot_part[0] = boot_part[0]->next(boot_part[0]);
- }
- if (is_me)
- return drive;
- }
-
- return -1;
-}
-
-static void do_boot(struct data_area *data, int ndata,
- struct syslinux_rm_regs *regs)
-{
- uint16_t *const bios_fbm = (uint16_t *) 0x413;
- addr_t dosmem = *bios_fbm << 10; /* Technically a low bound */
- struct syslinux_memmap *mmap;
- struct syslinux_movelist *mlist = NULL;
- addr_t endimage;
- uint8_t driveno = regs->edx.b[0];
- uint8_t swapdrive = driveno & 0x80;
- int i;
-
- mmap = syslinux_memory_map();
-
- if (!mmap) {
- error("Cannot read system memory map\n");
- return;
- }
-
- endimage = 0;
- for (i = 0; i < ndata; i++) {
- if (data[i].base + data[i].size > endimage)
- endimage = data[i].base + data[i].size;
- }
- if (endimage > dosmem)
- goto too_big;
-
- for (i = 0; i < ndata; i++) {
- if (syslinux_add_movelist(&mlist, data[i].base,
- (addr_t) data[i].data, data[i].size))
- goto enomem;
- }
-
- if (opt.swap && driveno != swapdrive) {
- static const uint8_t swapstub_master[] = {
- /* The actual swap code */
- 0x53, /* 00: push bx */
- 0x0f, 0xb6, 0xda, /* 01: movzx bx,dl */
- 0x2e, 0x8a, 0x57, 0x60, /* 04: mov dl,[cs:bx+0x60] */
- 0x5b, /* 08: pop bx */
- 0xea, 0, 0, 0, 0, /* 09: jmp far 0:0 */
- 0x90, 0x90, /* 0E: nop; nop */
- /* Code to install this in the right location */
- /* Entry with DS = CS; ES = SI = 0; CX = 256 */
- 0x26, 0x66, 0x8b, 0x7c, 0x4c, /* 10: mov edi,[es:si+4*0x13] */
- 0x66, 0x89, 0x3e, 0x0a, 0x00, /* 15: mov [0x0A],edi */
- 0x26, 0x8b, 0x3e, 0x13, 0x04, /* 1A: mov di,[es:0x413] */
- 0x4f, /* 1F: dec di */
- 0x26, 0x89, 0x3e, 0x13, 0x04, /* 20: mov [es:0x413],di */
- 0x66, 0xc1, 0xe7, 0x16, /* 25: shl edi,16+6 */
- 0x26, 0x66, 0x89, 0x7c, 0x4c, /* 29: mov [es:si+4*0x13],edi */
- 0x66, 0xc1, 0xef, 0x10, /* 2E: shr edi,16 */
- 0x8e, 0xc7, /* 32: mov es,di */
- 0x31, 0xff, /* 34: xor di,di */
- 0xf3, 0x66, 0xa5, /* 36: rep movsd */
- 0xbe, 0, 0, /* 39: mov si,0 */
- 0xbf, 0, 0, /* 3C: mov di,0 */
- 0x8e, 0xde, /* 3F: mov ds,si */
- 0x8e, 0xc7, /* 41: mov es,di */
- 0x66, 0xb9, 0, 0, 0, 0, /* 43: mov ecx,0 */
- 0x66, 0xbe, 0, 0, 0, 0, /* 49: mov esi,0 */
- 0x66, 0xbf, 0, 0, 0, 0, /* 4F: mov edi,0 */
- 0xea, 0, 0, 0, 0, /* 55: jmp 0:0 */
- /* pad out to segment boundary */
- 0x90, 0x90, /* 5A: ... */
- 0x90, 0x90, 0x90, 0x90, /* 5C: ... */
- };
- static uint8_t swapstub[1024];
- uint8_t *p;
-
- /* Note: we can't rely on either INT 13h nor the dosmem
- vector to be correct at this stage, so we have to use an
- installer stub to put things in the right place.
- Round the installer location to a 1K boundary so the only
- possible overlap is the identity mapping. */
- endimage = (endimage + 1023) & ~1023;
-
- /* Create swap stub */
- memcpy(swapstub, swapstub_master, sizeof swapstub_master);
- *(uint16_t *) & swapstub[0x3a] = regs->ds;
- *(uint16_t *) & swapstub[0x3d] = regs->es;
- *(uint32_t *) & swapstub[0x45] = regs->ecx.l;
- *(uint32_t *) & swapstub[0x4b] = regs->esi.l;
- *(uint32_t *) & swapstub[0x51] = regs->edi.l;
- *(uint16_t *) & swapstub[0x56] = regs->ip;
- *(uint16_t *) & swapstub[0x58] = regs->cs;
- p = &swapstub[sizeof swapstub_master];
-
- /* Mapping table; start out with identity mapping everything */
- for (i = 0; i < 256; i++)
- p[i] = i;
-
- /* And the actual swap */
- p[driveno] = swapdrive;
- p[swapdrive] = driveno;
-
- /* Adjust registers */
- regs->ds = regs->cs = endimage >> 4;
- regs->es = regs->esi.l = 0;
- regs->ecx.l = sizeof swapstub >> 2;
- regs->ip = 0x10; /* Installer offset */
- regs->ebx.b[0] = regs->edx.b[0] = swapdrive;
-
- if (syslinux_add_movelist(&mlist, endimage, (addr_t) swapstub,
- sizeof swapstub))
- goto enomem;
-
- endimage += sizeof swapstub;
- }
-
- /* Tell the shuffler not to muck with this area... */
- syslinux_add_memmap(&mmap, endimage, 0xa0000 - endimage, SMT_RESERVED);
-
- /* Force text mode */
- syslinux_force_text_mode();
-
- fputs("Booting...\n", stdout);
- syslinux_shuffle_boot_rm(mlist, mmap, opt.keeppxe, regs);
- error("Chainboot failed!\n");
- return;
-
-too_big:
- error("Loader file too large\n");
- return;
-
-enomem:
- error("Out of memory\n");
- return;
-}
-
-static int hide_unhide(struct mbr *mbr, int part)
-{
- int i;
- struct part_entry *pt;
- const uint16_t mask =
- (1 << 0x01) | (1 << 0x04) | (1 << 0x06) | (1 << 0x07) | (1 << 0x0b) | (1
- <<
- 0x0c)
- | (1 << 0x0e);
- uint8_t t;
- bool write_back = false;
-
- for (i = 1; i <= 4; i++) {
- pt = mbr->table + i - 1;
- t = pt->ostype;
- if ((t <= 0x1f) && ((mask >> (t & ~0x10)) & 1)) {
- /* It's a hideable partition type */
- if (i == part)
- t &= ~0x10; /* unhide */
- else
- t |= 0x10; /* hide */
- }
- if (t != pt->ostype) {
- write_back = true;
- pt->ostype = t;
- }
- }
-
- if (write_back)
- return write_verify_sector(0, mbr);
-
- return 0; /* ok */
-}
-
-static uint32_t get_file_lba(const char *filename)
-{
- com32sys_t inregs;
- uint32_t lba;
-
- /* Start with clean registers */
- memset(&inregs, 0, sizeof(com32sys_t));
-
- /* Put the filename in the bounce buffer */
- strlcpy(__com32.cs_bounce, filename, __com32.cs_bounce_size);
-
- /* Call comapi_open() which returns a structure pointer in SI
- * to a structure whose first member happens to be the LBA.
- */
- inregs.eax.w[0] = 0x0006;
- inregs.esi.w[0] = OFFS(__com32.cs_bounce);
- inregs.es = SEG(__com32.cs_bounce);
- __com32.cs_intcall(0x22, &inregs, &inregs);
-
- if ((inregs.eflags.l & EFLAGS_CF) || inregs.esi.w[0] == 0) {
- return 0; /* Filename not found */
- }
-
- /* Since the first member is the LBA, we simply cast */
- lba = *((uint32_t *) MK_PTR(inregs.ds, inregs.esi.w[0]));
-
- /* Clean the registers for the next call */
- memset(&inregs, 0, sizeof(com32sys_t));
-
- /* Put the filename in the bounce buffer */
- strlcpy(__com32.cs_bounce, filename, __com32.cs_bounce_size);
-
- /* Call comapi_close() to free the structure */
- inregs.eax.w[0] = 0x0008;
- inregs.esi.w[0] = OFFS(__com32.cs_bounce);
- inregs.es = SEG(__com32.cs_bounce);
- __com32.cs_intcall(0x22, &inregs, &inregs);
-
- return lba;
-}
-
-static void usage(void)
-{
- static const char usage[] = "\
-Usage: chain.c32 [options]\n\
- chain.c32 hd<disk#> [<partition>] [options]\n\
- chain.c32 fd<disk#> [options]\n\
- chain.c32 mbr:<id> [<partition>] [options]\n\
- chain.c32 guid:<guid> [<partition>] [options]\n\
- chain.c32 label:<label> [<partition>] [options]\n\
- chain.c32 boot [<partition>] [options]\n\
- chain.c32 fs [options]\n\
-Options: file=<loader> Load and execute file, instead of boot sector\n\
- isolinux=<loader> Load another version of ISOLINUX\n\
- ntldr=<loader> Load Windows NTLDR, SETUPLDR.BIN or BOOTMGR\n\
- cmldr=<loader> Load Recovery Console of Windows NT/2K/XP/2003\n\
- freedos=<loader> Load FreeDOS KERNEL.SYS\n\
- msdos=<loader> Load MS-DOS IO.SYS\n\
- pcdos=<loader> Load PC-DOS IBMBIO.COM\n\
- drmk=<loader> Load DRMK DELLBIO.BIN\n\
- grub=<loader> Load GRUB Legacy stage2\n\
- grubcfg=<filename> Set alternative config filename for GRUB Legacy\n\
- grldr=<loader> Load GRUB4DOS grldr\n\
- seg=<segment> Jump to <seg>:0000, instead of 0000:7C00\n\
- swap Swap drive numbers, if bootdisk is not fd0/hd0\n\
- hide Hide primary partitions, except selected partition\n\
- sethidden Set the FAT/NTFS hidden sectors field\n\
- keeppxe Keep the PXE and UNDI stacks in memory (PXELINUX)\n\
-See syslinux/com32/modules/chain.c for more information\n";
- error(usage);
-}
-
-int main(int argc, char *argv[])
-{
- struct mbr *mbr = NULL;
- char *p;
- struct disk_part_iter *cur_part = NULL;
- struct syslinux_rm_regs regs;
- char *drivename, *partition;
- int hd, drive, whichpart = 0; /* MBR by default */
- int i;
- uint64_t fs_lba = 0; /* Syslinux partition */
- uint32_t file_lba = 0;
- struct guid gpt_guid;
- unsigned char *isolinux_bin;
- uint32_t *checksum, *chkhead, *chktail;
- struct data_area data[3];
- int ndata = 0;
- addr_t load_base;
- static const char cmldr_signature[8] = "cmdcons";
-
- openconsole(&dev_null_r, &dev_stdcon_w);
-
- drivename = "boot";
- partition = NULL;
-
- /* Prepare the register set */
- memset(&regs, 0, sizeof regs);
-
- for (i = 1; i < argc; i++) {
- if (!strncmp(argv[i], "file=", 5)) {
- opt.loadfile = argv[i] + 5;
- } else if (!strncmp(argv[i], "seg=", 4)) {
- uint32_t segval = strtoul(argv[i] + 4, NULL, 0);
- if (segval < 0x50 || segval > 0x9f000) {
- error("Invalid segment\n");
- goto bail;
- }
- opt.seg = segval;
- } else if (!strncmp(argv[i], "isolinux=", 9)) {
- opt.loadfile = argv[i] + 9;
- opt.isolinux = true;
- } else if (!strncmp(argv[i], "ntldr=", 6)) {
- opt.seg = 0x2000; /* NTLDR wants this address */
- opt.loadfile = argv[i] + 6;
- opt.sethidden = true;
- } else if (!strncmp(argv[i], "cmldr=", 6)) {
- opt.seg = 0x2000; /* CMLDR wants this address */
- opt.loadfile = argv[i] + 6;
- opt.cmldr = true;
- opt.sethidden = true;
- } else if (!strncmp(argv[i], "freedos=", 8)) {
- opt.seg = 0x60; /* FREEDOS wants this address */
- opt.loadfile = argv[i] + 8;
- opt.sethidden = true;
- } else if (!strncmp(argv[i], "msdos=", 6) ||
- !strncmp(argv[i], "pcdos=", 6)) {
- opt.seg = 0x70; /* MS-DOS 2.0+ wants this address */
- opt.loadfile = argv[i] + 6;
- opt.sethidden = true;
- } else if (!strncmp(argv[i], "drmk=", 5)) {
- opt.seg = 0x70; /* DRMK wants this address */
- opt.loadfile = argv[i] + 5;
- opt.sethidden = true;
- opt.drmk = true;
- } else if (!strncmp(argv[i], "grub=", 5)) {
- opt.seg = 0x800; /* stage2 wants this address */
- opt.loadfile = argv[i] + 5;
- opt.grub = true;
- } else if (!strncmp(argv[i], "grubcfg=", 8)) {
- opt.grubcfg = argv[i] + 8;
- } else if (!strncmp(argv[i], "grldr=", 6)) {
- opt.loadfile = argv[i] + 6;
- opt.grldr = true;
- } else if (!strcmp(argv[i], "swap")) {
- opt.swap = true;
- } else if (!strcmp(argv[i], "noswap")) {
- opt.swap = false;
- } else if (!strcmp(argv[i], "hide")) {
- opt.hide = true;
- } else if (!strcmp(argv[i], "nohide")) {
- opt.hide = false;
- } else if (!strcmp(argv[i], "keeppxe")) {
- opt.keeppxe = 3;
- } else if (!strcmp(argv[i], "sethidden")) {
- opt.sethidden = true;
- } else if (!strcmp(argv[i], "nosethidden")) {
- opt.sethidden = false;
- } else if (((argv[i][0] == 'h' || argv[i][0] == 'f')
- && argv[i][1] == 'd')
- || !strncmp(argv[i], "mbr:", 4)
- || !strncmp(argv[i], "mbr=", 4)
- || !strncmp(argv[i], "guid:", 5)
- || !strncmp(argv[i], "guid=", 5)
- || !strncmp(argv[i], "uuid:", 5)
- || !strncmp(argv[i], "uuid=", 5)
- || !strncmp(argv[i], "label:", 6)
- || !strncmp(argv[i], "label=", 6)
- || !strcmp(argv[i], "boot")
- || !strncmp(argv[i], "boot,", 5)
- || !strcmp(argv[i], "fs")) {
- drivename = argv[i];
- p = strchr(drivename, ',');
- if (p) {
- *p = '\0';
- partition = p + 1;
- } else if (argv[i + 1] && argv[i + 1][0] >= '0'
- && argv[i + 1][0] <= '9') {
- partition = argv[++i];
- }
- } else {
- usage();
- goto bail;
- }
- }
-
- if (opt.grubcfg && !opt.grub) {
- error("grubcfg=<filename> must be used together with grub=<loader>.\n");
- goto bail;
- }
-
- if (opt.seg) {
- regs.es = regs.cs = regs.ss = regs.ds = regs.fs = regs.gs = opt.seg;
- } else {
- regs.ip = regs.esp.l = 0x7c00;
- }
-
- hd = 0;
- if (!strncmp(drivename, "mbr", 3)) {
- drive = find_disk(strtoul(drivename + 4, NULL, 0));
- if (drive == -1) {
- error("Unable to find requested MBR signature\n");
- goto bail;
- }
- } else if (!strncmp(drivename, "guid", 4) ||
- !strncmp(drivename, "uuid", 4)) {
- if (str_to_guid(drivename + 5, &gpt_guid))
- goto bail;
- drive = find_by_guid(&gpt_guid, &cur_part);
- if (drive == -1) {
- error("Unable to find requested GPT disk/partition\n");
- goto bail;
- }
- } else if (!strncmp(drivename, "label", 5)) {
- if (!drivename[6]) {
- error("No label specified.\n");
- goto bail;
- }
- drive = find_by_label(drivename + 6, &cur_part);
- if (drive == -1) {
- error("Unable to find requested partition by label\n");
- goto bail;
- }
- } else if ((drivename[0] == 'h' || drivename[0] == 'f') &&
- drivename[1] == 'd') {
- hd = drivename[0] == 'h';
- drivename += 2;
- drive = (hd ? 0x80 : 0) | strtoul(drivename, NULL, 0);
- } else if (!strcmp(drivename, "boot") || !strcmp(drivename, "fs")) {
- const union syslinux_derivative_info *sdi;
-
- sdi = syslinux_derivative_info();
- if (sdi->c.filesystem == SYSLINUX_FS_PXELINUX)
- drive = 0x80; /* Boot drive not available */
- else
- drive = sdi->disk.drive_number;
- if (!strcmp(drivename, "fs")
- && (sdi->c.filesystem == SYSLINUX_FS_SYSLINUX
- || sdi->c.filesystem == SYSLINUX_FS_EXTLINUX
- || sdi->c.filesystem == SYSLINUX_FS_ISOLINUX))
- /* We should lookup the Syslinux partition number and use it */
- fs_lba = *sdi->disk.partoffset;
- } else {
- error("Unparsable drive specification\n");
- goto bail;
- }
-
- /* DOS kernels want the drive number in BL instead of DL. Indulge them. */
- regs.ebx.b[0] = regs.edx.b[0] = drive;
-
- /* Get the disk geometry and disk access setup */
- if (get_disk_params(drive)) {
- error("Cannot get disk parameters\n");
- goto bail;
- }
-
- /* Get MBR */
- if (!(mbr = read_sectors(0, 1))) {
- error("Cannot read Master Boot Record or sector 0\n");
- goto bail;
- }
-
- if (partition)
- whichpart = strtoul(partition, NULL, 0);
- /* "guid:" or "label:" might have specified a partition */
- if (cur_part)
- whichpart = cur_part->index;
-
- /* Boot the MBR by default */
- if (!cur_part && (whichpart || fs_lba)) {
- /* Boot a partition, possibly the Syslinux partition itself */
- cur_part = get_first_partition(NULL);
- while (cur_part) {
- if ((cur_part->index == whichpart)
- || (cur_part->lba_data == fs_lba))
- /* Found the partition to boot */
- break;
- cur_part = cur_part->next(cur_part);
- }
- if (!cur_part) {
- error("Requested partition not found!\n");
- goto bail;
- }
- whichpart = cur_part->index;
- }
-
- if (!(drive & 0x80) && whichpart) {
- error("Warning: Partitions of floppy devices may not work\n");
- }
-
- /*
- * GRLDR of GRUB4DOS wants the partition number in DH:
- * -1: whole drive (default)
- * 0-3: primary partitions
- * 4-*: logical partitions
- */
- if (opt.grldr)
- regs.edx.b[1] = whichpart - 1;
-
- if (opt.hide) {
- if (whichpart < 1 || whichpart > 4)
- error("WARNING: hide specified without a non-primary partition\n");
- if (hide_unhide(mbr, whichpart))
- error("WARNING: failed to write MBR for 'hide'\n");
- }
-
- /* Do the actual chainloading */
- load_base = opt.seg ? (opt.seg << 4) : 0x7c00;
-
- if (opt.loadfile) {
- fputs("Loading the boot file...\n", stdout);
- if (loadfile(opt.loadfile, &data[ndata].data, &data[ndata].size)) {
- error("Failed to load the boot file\n");
- goto bail;
- }
- data[ndata].base = load_base;
- load_base = 0x7c00; /* If we also load a boot sector */
-
- /* Create boot info table: needed when you want to chainload
- another version of ISOLINUX (or another bootlaoder that needs
- the -boot-info-table switch of mkisofs)
- (will only work when run from ISOLINUX) */
- if (opt.isolinux) {
- const union syslinux_derivative_info *sdi;
- sdi = syslinux_derivative_info();
-
- if (sdi->c.filesystem == SYSLINUX_FS_ISOLINUX) {
- /* Boot info table info (integers in little endian format)
-
- Offset Name Size Meaning
- 8 bi_pvd 4 bytes LBA of primary volume descriptor
- 12 bi_file 4 bytes LBA of boot file
- 16 bi_length 4 bytes Boot file length in bytes
- 20 bi_csum 4 bytes 32-bit checksum
- 24 bi_reserved 40 bytes Reserved
-
- The 32-bit checksum is the sum of all the 32-bit words in the
- boot file starting at byte offset 64. All linear block
- addresses (LBAs) are given in CD sectors (normally 2048 bytes).
-
- LBA of primary volume descriptor should already be set to 16.
- */
-
- isolinux_bin = (unsigned char *)data[ndata].data;
-
- /* Get LBA address of bootfile */
- file_lba = get_file_lba(opt.loadfile);
-
- if (file_lba == 0) {
- error("Failed to find LBA offset of the boot file\n");
- goto bail;
- }
- /* Set it */
- *((uint32_t *) & isolinux_bin[12]) = file_lba;
-
- /* Set boot file length */
- *((uint32_t *) & isolinux_bin[16]) = data[ndata].size;
-
- /* Calculate checksum */
- checksum = (uint32_t *) & isolinux_bin[20];
- chkhead = (uint32_t *) & isolinux_bin[64];
- chktail = (uint32_t *) & isolinux_bin[data[ndata].size & ~3];
- *checksum = 0;
- while (chkhead < chktail)
- *checksum += *chkhead++;
-
- /*
- * Deal with possible fractional dword at the end;
- * this *should* never happen...
- */
- if (data[ndata].size & 3) {
- uint32_t xword = 0;
- memcpy(&xword, chkhead, data[ndata].size & 3);
- *checksum += xword;
- }
- } else {
- error
- ("The isolinux= option is only valid when run from ISOLINUX\n");
- goto bail;
- }
- }
-
- if (opt.grub) {
- /* Layout of stage2 file (from byte 0x0 to 0x270) */
- struct grub_stage2_patch_area {
- /* 0x0 to 0x205 */
- char unknown[0x206];
- /* 0x206: compatibility version number major */
- uint8_t compat_version_major;
- /* 0x207: compatibility version number minor */
- uint8_t compat_version_minor;
-
- /* 0x208: install_partition variable */
- struct {
- /* 0x208: sub-partition in sub-partition part2 */
- uint8_t part3;
- /* 0x209: sub-partition in top-level partition */
- uint8_t part2;
- /* 0x20a: top-level partiton number */
- uint8_t part1;
- /* 0x20b: BIOS drive number (must be 0) */
- uint8_t drive;
- } __attribute__ ((packed)) install_partition;
-
- /* 0x20c: deprecated (historical reason only) */
- uint32_t saved_entryno;
- /* 0x210: stage2_ID: will always be STAGE2_ID_STAGE2 = 0 in stage2 */
- uint8_t stage2_id;
- /* 0x211: force LBA */
- uint8_t force_lba;
- /* 0x212: version string (will probably be 0.97) */
- char version_string[5];
- /* 0x217: config filename */
- char config_file[89];
- /* 0x270: start of code (after jump from 0x200) */
- char codestart[1];
- } __attribute__ ((packed)) *stage2;
-
- if (data[ndata].size < sizeof(struct grub_stage2_patch_area)) {
- error
- ("The file specified by grub=<loader> is to small to be stage2 of GRUB Legacy.\n");
- goto bail;
- }
-
- stage2 = data[ndata].data;
-
- /*
- * Check the compatibility version number to see if we loaded a real
- * stage2 file or a stage2 file that we support.
- */
- if (stage2->compat_version_major != 3
- || stage2->compat_version_minor != 2) {
- error
- ("The file specified by grub=<loader> is not a supported stage2 GRUB Legacy binary\n");
- goto bail;
- }
-
- /* jump 0x200 bytes into the loadfile */
- regs.ip = 0x200;
-
- /*
- * GRUB Legacy wants the partition number in the install_partition
- * variable, located at offset 0x208 of stage2.
- * When GRUB Legacy is loaded, it is located at memory address 0x8208.
- *
- * It looks very similar to the "boot information format" of the
- * Multiboot specification:
- * http://www.gnu.org/software/grub/manual/multiboot/multiboot.html#Boot-information-format
- *
- * 0x208 = part3: sub-partition in sub-partition part2
- * 0x209 = part2: sub-partition in top-level partition
- * 0x20a = part1: top-level partition number
- * 0x20b = drive: BIOS drive number (must be 0)
- *
- * GRUB Legacy doesn't store the BIOS drive number at 0x20b, but at
- * another location.
- *
- * Partition numbers always start from zero.
- * Unused partition bytes must be set to 0xFF.
- *
- * We only care about top-level partition, so we only need to change
- * "part1" to the appropriate value:
- * -1: whole drive (default) (-1 = 0xFF)
- * 0-3: primary partitions
- * 4-*: logical partitions
- */
- stage2->install_partition.part1 = whichpart - 1;
-
- /*
- * Grub Legacy reserves 89 bytes (from 0x8217 to 0x826f) for the
- * config filename. The filename passed via grubcfg= will overwrite
- * the default config filename "/boot/grub/menu.lst".
- */
- if (opt.grubcfg) {
- if (strlen(opt.grubcfg) > sizeof(stage2->config_file) - 1) {
- error
- ("The config filename length can't exceed 88 characters.\n");
- goto bail;
- }
-
- strcpy((char *)stage2->config_file, opt.grubcfg);
- }
- }
-
- if (opt.drmk) {
- /* DRMK entry is different than MS-DOS/PC-DOS */
- /*
- * A new size, aligned to 16 bytes to ease use of ds:[bp+28].
- * We only really need 4 new, usable bytes at the end.
- */
- int tsize = (data[ndata].size + 19) & 0xfffffff0;
- const union syslinux_derivative_info *sdi;
-
- sdi = syslinux_derivative_info();
- /* We should lookup the Syslinux partition offset and use it */
- fs_lba = *sdi->disk.partoffset;
- /*
- * fs_lba should be verified against the disk as some DRMK
- * variants will check and fail if it does not match
- */
- dprintf(" fs_lba offset is %d\n", fs_lba);
- /* DRMK only uses a DWORD */
- if (fs_lba > 0xffffffff) {
- error("LBA very large; Only using lower 32 bits; DRMK will probably fail\n");
- }
- regs.ss = regs.fs = regs.gs = 0; /* Used before initialized */
- if (!realloc(data[ndata].data, tsize)) {
- error("Failed to realloc for DRMK\n");
- goto bail; /* We'll never make it */
- }
- data[ndata].size = tsize;
- /* ds:bp is assumed by DRMK to be the boot sector */
- /* offset 28 is the FAT HiddenSectors value */
- regs.ds = (tsize >> 4) + (opt.seg - 2);
- /* "Patch" into tail of the new space */
- *(int *)(data[ndata].data + tsize - 4) = (int)(fs_lba & 0xffffffff);
- }
-
- ndata++;
- }
-
- if (!opt.loadfile || data[0].base >= 0x7c00 + SECTOR) {
- /* Actually read the boot sector */
- if (!cur_part) {
- data[ndata].data = mbr;
- } else if (!(data[ndata].data = read_sectors(cur_part->lba_data, 1))) {
- error("Cannot read boot sector\n");
- goto bail;
- }
- data[ndata].size = SECTOR;
- data[ndata].base = load_base;
-
- if (!opt.loadfile) {
- const struct mbr *br =
- (const struct mbr *)((char *)data[ndata].data +
- data[ndata].size - sizeof(struct mbr));
- if (br->sig != mbr_sig_magic) {
- error
- ("Boot sector signature not found (unbootable disk/partition?)\n");
- goto bail;
- }
- }
- /*
- * To boot the Recovery Console of Windows NT/2K/XP we need to write
- * the string "cmdcons\0" to memory location 0000:7C03.
- * Memory location 0000:7C00 contains the bootsector of the partition.
- */
- if (cur_part && opt.cmldr) {
- memcpy((char *)data[ndata].data + 3, cmldr_signature,
- sizeof cmldr_signature);
- }
-
- /*
- * Modify the hidden sectors (partition offset) copy in memory;
- * this modifies the field used by FAT and NTFS filesystems, and
- * possibly other boot loaders which use the same format.
- */
- if (cur_part && opt.sethidden) {
- *(uint32_t *) ((char *)data[ndata].data + 28) = cur_part->lba_data;
- }
-
- ndata++;
- }
-
- if (cur_part) {
- if (cur_part->next == next_gpt_part) {
- /* Do GPT hand-over, if applicable (as per syslinux/doc/gpt.txt) */
- struct part_entry *record;
- /* Look at the GPT partition */
- const struct gpt_part *gp = (const struct gpt_part *)
- (cur_part->block +
- (cur_part->private.gpt.size * cur_part->private.gpt.index));
- /* Note the partition length */
- uint64_t lba_count = gp->lba_last - gp->lba_first + 1;
- /* The length of the hand-over */
- int synth_size =
- sizeof(struct part_entry) + sizeof(uint32_t) +
- cur_part->private.gpt.size;
- /* Will point to the partition record length in the hand-over */
- uint32_t *plen;
-
- /* Allocate the hand-over record */
- record = malloc(synth_size);
- if (!record) {
- error("Could not build GPT hand-over record!\n");
- goto bail;
- }
- /* Synthesize the record */
- memset(record, 0, synth_size);
- record->active_flag = 0x80;
- record->ostype = 0xED;
- /* All bits set by default */
- record->start_lba = ~(uint32_t) 0;
- record->length = ~(uint32_t) 0;
- /* If these fit the precision, pass them on */
- if (cur_part->lba_data < record->start_lba)
- record->start_lba = cur_part->lba_data;
- if (lba_count < record->length)
- record->length = lba_count;
- /* Next comes the GPT partition record length */
- plen = (uint32_t *) (record + 1);
- plen[0] = cur_part->private.gpt.size;
- /* Next comes the GPT partition record copy */
- memcpy(plen + 1, gp, plen[0]);
- cur_part->record = record;
-
- regs.eax.l = 0x54504721; /* '!GPT' */
- data[ndata].base = 0x7be;
- data[ndata].size = synth_size;
- data[ndata].data = (void *)record;
- ndata++;
- regs.esi.w[0] = 0x7be;
-
- dprintf("GPT handover:\n");
- mbr_part_dump(record);
- gpt_part_dump((struct gpt_part *)(plen + 1));
- } else if (cur_part->record) {
- /* MBR handover protocol */
- static struct part_entry handover_record;
-
- handover_record = *cur_part->record;
- handover_record.start_lba = cur_part->lba_data;
-
- data[ndata].base = 0x7be;
- data[ndata].size = sizeof handover_record;
- data[ndata].data = &handover_record;
- ndata++;
- regs.esi.w[0] = 0x7be;
-
- dprintf("MBR handover:\n");
- mbr_part_dump(&handover_record);
- }
- }
-
- do_boot(data, ndata, &regs);
-
-bail:
- if (cur_part) {
- free(cur_part->block);
- free((void *)cur_part->record);
- }
- free(cur_part);
- free(mbr);
- return 255;
-}