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authorH. Peter Anvin <hpa@linux.intel.com>2010-06-25 13:48:49 -0700
committerH. Peter Anvin <hpa@linux.intel.com>2010-06-25 13:48:49 -0700
commit4a3a963498853111ecd0a352a125cfc58491dd41 (patch)
tree60de935b0e6a32aa97011a48b834f1b3344da43f /com32/modules
parentd61a4a879b6a6a875b06e3cb461470b82b0ecb41 (diff)
parent89b665c55648e2bce662332be5ba60381d9f6cec (diff)
downloadsyslinux-4a3a963498853111ecd0a352a125cfc58491dd41.tar.gz
syslinux-4a3a963498853111ecd0a352a125cfc58491dd41.tar.xz
syslinux-4a3a963498853111ecd0a352a125cfc58491dd41.zip
Merge remote branch 'sha0/chain_gpt'
Diffstat (limited to 'com32/modules')
-rw-r--r--com32/modules/chain.c856
1 files changed, 660 insertions, 196 deletions
diff --git a/com32/modules/chain.c b/com32/modules/chain.c
index 93bba4ea..6f3729f9 100644
--- a/com32/modules/chain.c
+++ b/com32/modules/chain.c
@@ -2,6 +2,8 @@
*
* Copyright 2003-2009 H. Peter Anvin - All Rights Reserved
* Copyright 2009-2010 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
@@ -16,24 +18,32 @@
*
* Chainload a hard disk (currently rather braindead.)
*
- * Usage: chain hd<disk#> [<partition>] [options]
+ * Usage: chain [options]
+ * chain hd<disk#> [<partition>] [options]
* chain fd<disk#> [options]
* chain mbr:<id> [<partition>] [options]
* chain boot [<partition>] [options]
*
- * ... e.g. "chain hd0 1" will boot the first partition on the first hard
+ * 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:", "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**
+ * loads the file <loader> **from the Syslinux filesystem**
* instead of loading the boot sector.
*
* seg=<segment>:
@@ -81,6 +91,8 @@
* FAT/NTFS boot sector.
*/
+#define DEBUG 0 /* 1 to enable */
+
#include <com32.h>
#include <stdlib.h>
#include <stdio.h>
@@ -204,18 +216,23 @@ struct ebios_dapa {
uint64_t lba;
};
-static void *read_sector(unsigned int 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 = 1; /* 1 sector */
+ dapa->count = count;
dapa->off = OFFS(buf);
dapa->seg = SEG(buf);
dapa->lba = lba;
@@ -246,7 +263,8 @@ static void *read_sector(unsigned int lba)
if (s > 63 || h > 256 || c > 1023)
return NULL;
- inreg.eax.w[0] = 0x0201; /* Read one sector */
+ inreg.eax.b[0] = count;
+ inreg.eax.b[1] = 0x02; /* Read */
inreg.ecx.b[1] = c & 0xff;
inreg.ecx.b[0] = s + (c >> 6);
inreg.edx.b[1] = h;
@@ -258,9 +276,9 @@ static void *read_sector(unsigned int lba)
if (int13_retry(&inreg, NULL))
return NULL;
- data = malloc(SECTOR);
+ data = malloc(count * SECTOR);
if (data)
- memcpy(data, buf, SECTOR);
+ memcpy(data, buf, count * SECTOR);
return data;
}
@@ -329,7 +347,7 @@ static int write_verify_sector(unsigned int lba, const void *buf)
rv = write_sector(lba, buf);
if (rv)
return rv; /* Write failure */
- rb = read_sector(lba);
+ rb = read_sectors(lba, 1);
if (!rb)
return -1; /* Readback failure */
rv = memcmp(buf, rb, SECTOR);
@@ -337,132 +355,518 @@ static int write_verify_sector(unsigned int lba, const void *buf)
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));
+
+#if DEBUG
+static void mbr_part_dump(const struct part_entry *part)
+{
+ printf("-------------------------------\n"
+ "Partition status _____ : 0x%.2x\n"
+ "Partition CHS start\n"
+ " Cylinder ___________ : 0x%.4x\n"
+ " Head _______________ : 0x%.2x\n"
+ " Sector _____________ : 0x%.2x\n"
+ "Partition type _______ : 0x%.2x\n"
+ "Partition CHS end\n"
+ " Cylinder ___________ : 0x%.4x\n"
+ " Head _______________ : 0x%.2x\n"
+ " Sector _____________ : 0x%.2x\n"
+ "Partition LBA start __ : 0x%.16x\n"
+ "Partition LBA count __ : 0x%.16x\n",
+ part->active_flag,
+ chs_cylinder(part->start),
+ chs_head(part->start),
+ chs_sector(part->start),
+ part->ostype,
+ chs_cylinder(part->end),
+ chs_head(part->end),
+ chs_sector(part->end), part->start_lba, part->length);
+}
+#endif
+
+/* 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;
- char *buf;
+ struct mbr *mbr;
for (drive = 0x80; drive <= 0xff; drive++) {
if (get_disk_params(drive))
continue; /* Drive doesn't exist */
- if (!(buf = read_sector(0)))
+ if (!(mbr = read_sectors(0, 1)))
continue; /* Cannot read sector */
- is_me = (*(uint32_t *) ((char *)buf + 440) == mbr_sig);
- free(buf);
+ is_me = (mbr->disk_sig == mbr_sig);
+ free(mbr);
if (is_me)
return drive;
}
return -1;
}
-/* A DOS partition table entry */
-struct part_entry {
- uint8_t active_flag; /* 0x80 if "active" */
- uint8_t start_head;
- uint8_t start_sect;
- uint8_t start_cyl;
- uint8_t ostype;
- uint8_t end_head;
- uint8_t end_sect;
- uint8_t end_cyl;
- uint32_t start_lba;
- uint32_t length;
-} __attribute__ ((packed));
-
-/* Search for a logical partition. Logical partitions are actually implemented
- as recursive partition tables; theoretically they're supposed to form a
- linked list, but other structures have been seen.
-
- To make things extra confusing: data partition offsets are relative to where
- the data partition record is stored, whereas extended partition offsets
- are relative to the beginning of the extended partition all the way back
- at the MBR... but still not absolute! */
+/* 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;
+ /* Count of entries in GPT */
+ int parts;
+ /* Partition record size */
+ uint32_t size;
+ } gpt;
+ } private;
+};
-int nextpart; /* Number of the next logical partition */
+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;
+#if DEBUG
+ mbr_part_dump(ebr_table);
+#endif
+ /*
+ * 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) {
+ error("Insane logical partition!\n");
+ goto err_insane;
+ }
+ }
+ /* Success */
+ part->lba_data = ebr_table[0].start_lba + ebr_lba;
+ 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 part_entry *find_logical_partition(int whichpart, char *table,
- struct part_entry *self,
- struct part_entry *root)
+static struct disk_part_iter *next_mbr_part(struct disk_part_iter *part)
{
- static struct part_entry ltab_entry;
- struct part_entry *ptab = (struct part_entry *)(table + 0x1be);
- struct part_entry *found;
- char *sector;
+ struct disk_part_iter *ebr_part;
+ /* Look at the partition table */
+ struct part_entry *table = ((struct mbr *)part->block)->table;
- int i;
+ /* 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);
+ }
+#if DEBUG
+ mbr_part_dump(table + part->private.mbr_index);
+#endif
+ /* Update parameters to reflect this new partition. Re-use iterator */
+ part->lba_data = table[part->private.mbr_index].start_lba;
+ part->index++;
+ part->record = table + part->private.mbr_index;
+ return part;
+
+ free(ebr_part);
+err_alloc:
+
+ free(part->block);
+ free(part);
+ return NULL;
+}
- if (*(uint16_t *) (table + 0x1fe) != 0xaa55)
- return NULL; /* Signature missing */
+/*
+ * 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));
- /* We are assumed to already having enumerated all the data partitions
- in this table if this is the MBR. For MBR, self == NULL. */
+#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)
+{
+ /*
+ * This walk-map effectively reverses the little-endian
+ * portions of the GUID in the output text
+ */
+ static const char le_walk_map[] = {
+ 3, -1, -1, -1, 0,
+ 5, -1, 0,
+ 3, -1, 0,
+ 2, 1, 0,
+ 1, 1, 1, 1, 1, 1
+ };
+ unsigned int i = 0;
+ const char *walker = (const char *)id;
+
+ while (i < sizeof(le_walk_map)) {
+ walker += le_walk_map[i];
+ if (!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
+
+/* 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));
- if (self) {
- /* Scan the data partitions. */
+#if DEBUG
+static void gpt_part_dump(const struct gpt_part *gpt_part)
+{
+ unsigned int i;
+ char guid_text[37];
+
+ printf("----------------------------------\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])
+ printf("%c", gpt_part->name[i]);
+ }
+ puts("'");
+ guid_to_str(guid_text, &gpt_part->type);
+ printf("GPT part. type GUID __ : {%s}\n", guid_text);
+ guid_to_str(guid_text, &gpt_part->uid);
+ printf("GPT part. unique ID __ : {%s}\n", guid_text);
+}
+#endif
+
+/* 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";
- for (i = 0; i < 4; i++) {
- if (ptab[i].ostype == 0x00 || ptab[i].ostype == 0x05 ||
- ptab[i].ostype == 0x0f || ptab[i].ostype == 0x85)
- continue; /* Skip empty or extended partitions */
+#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
- if (!ptab[i].length)
- continue;
+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;
+ /* Update our index */
+ part->index++;
+#if DEBUG
+ gpt_part_dump(gpt_part);
+#endif
+ /* In a GPT scheme, we re-use the iterator */
+ return part;
+
+err_last:
+ free(part->block);
+ free(part);
- /* Adjust the offset to account for the extended partition itself */
- ptab[i].start_lba += self->start_lba;
+ return NULL;
+}
- /*
- * Sanity check entry: must not extend outside the
- * extended partition. This is necessary since some OSes
- * put crap in some entries. Note that root is non-NULL here.
- */
- if (ptab[i].start_lba + ptab[i].length <= root->start_lba ||
- ptab[i].start_lba >= root->start_lba + root->length)
- continue;
+static struct disk_part_iter *get_first_partition(struct disk_part_iter *part)
+{
+ const struct gpt *gpt_candidate;
- /* OK, it's a data partition. Is it the one we're looking for? */
- if (nextpart++ == whichpart) {
- memcpy(&ltab_entry, &ptab[i], sizeof ltab_entry);
- return &ltab_entry;
- }
+ /*
+ * 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);
- /* Scan the extended partitions. */
- for (i = 0; i < 4; i++) {
- if (ptab[i].ostype != 0x05 &&
- ptab[i].ostype != 0x0f && ptab[i].ostype != 0x85)
- continue; /* Skip empty or data partitions */
+err_gpt_table:
- if (!ptab[i].length)
- continue;
+err_mbr:
- /* Adjust the offset to account for the extended partition itself */
- if (root)
- ptab[i].start_lba += root->start_lba;
-
- /* Sanity check entry: must not extend outside the extended partition.
- This is necessary since some OSes put crap in some entries. */
- if (root)
- if (ptab[i].start_lba + ptab[i].length <= root->start_lba ||
- ptab[i].start_lba >= root->start_lba + root->length)
- continue;
-
- /* Process this partition */
- if (!(sector = read_sector(ptab[i].start_lba)))
- continue; /* Read error, must be invalid */
-
- found = find_logical_partition(whichpart, sector, &ptab[i],
- root ? root : &ptab[i]);
- free(sector);
- if (found)
- return found;
- }
+ free(part->block);
+ part->block = NULL;
+err_read_mbr:
+
+ free(part);
+err_alloc_iter:
- /* If we get here, there ain't nothing... */
return NULL;
}
@@ -495,7 +899,7 @@ static void do_boot(struct data_area *data, int ndata,
for (i = 0; i < ndata; i++) {
if (syslinux_add_movelist(&mlist, data[i].base,
- (addr_t)data[i].data, data[i].size))
+ (addr_t) data[i].data, data[i].size))
goto enomem;
}
@@ -587,16 +991,16 @@ static void do_boot(struct data_area *data, int ndata,
error("Chainboot failed!\n");
return;
- too_big:
+too_big:
error("Loader file too large\n");
return;
- enomem:
+enomem:
error("Out of memory\n");
return;
}
-static int hide_unhide(char *mbr, int part)
+static int hide_unhide(struct mbr *mbr, int part)
{
int i;
struct part_entry *pt;
@@ -609,7 +1013,7 @@ static int hide_unhide(char *mbr, int part)
bool write_back = false;
for (i = 1; i <= 4; i++) {
- pt = (struct part_entry *)&mbr[0x1be + 16 * (i - 1)];
+ pt = mbr->table + i - 1;
t = pt->ostype;
if ((t <= 0x1f) && ((mask >> (t & ~0x10)) & 1)) {
/* It's a hideable partition type */
@@ -673,34 +1077,39 @@ static uint32_t get_file_lba(const char *filename)
static void usage(void)
{
- error("Usage: chain.c32 hd<disk#> [<partition>] [options]\n"
- " chain.c32 fd<disk#> [options]\n"
- " chain.c32 mbr:<id> [<partition>] [options]\n"
- " chain.c32 boot [<partition>] [options]\n"
- "Options: file=<loader> load 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\n"
- " freedos=<loader> load FreeDOS kernel.sys\n"
- " msdos=<loader> load MS-DOS io.sys\n"
- " pcdos=<loader> load PC-DOS ibmbio.com\n"
- " grub=<loader> load GRUB stage2\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"
- );
+ 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 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\
+ grub=<loader> Load GRUB stage2\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\
+See syslinux/com32/modules/chain.c for more information\n";
+ error(usage);
}
-
int main(int argc, char *argv[])
{
- char *mbr, *p;
- struct part_entry *partinfo;
+ 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;
+ int hd, drive, whichpart = 0; /* MBR by default */
int i;
+ uint64_t fs_lba = 0; /* Syslinux partition */
uint32_t file_lba = 0;
unsigned char *isolinux_bin;
uint32_t *checksum, *chkhead, *chktail;
@@ -735,7 +1144,7 @@ int main(int argc, char *argv[])
opt.loadfile = argv[i] + 6;
opt.sethidden = true;
} else if (!strncmp(argv[i], "cmldr=", 6)) {
- opt.seg = 0x2000; /* CMLDR wants this address */
+ opt.seg = 0x2000; /* CMLDR wants this address */
opt.loadfile = argv[i] + 6;
opt.cmldr = true;
opt.sethidden = true;
@@ -771,7 +1180,8 @@ int main(int argc, char *argv[])
|| !strncmp(argv[i], "mbr:", 4)
|| !strncmp(argv[i], "mbr=", 4)
|| !strcmp(argv[i], "boot")
- || !strncmp(argv[i], "boot,", 5)) {
+ || !strncmp(argv[i], "boot,", 5)
+ || !strncmp(argv[i], "fs", 2)) {
drivename = argv[i];
p = strchr(drivename, ',');
if (p) {
@@ -805,13 +1215,19 @@ int main(int argc, char *argv[])
hd = drivename[0] == 'h';
drivename += 2;
drive = (hd ? 0x80 : 0) | strtoul(drivename, NULL, 0);
- } else if (!strcmp(drivename, "boot")) {
+ } 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))
+ /* We should lookup the Syslinux partition number and use it */
+ fs_lba = ((struct part_entry *)sdi->disk.ptab_ptr)->start_lba;
} else {
error("Unparsable drive specification\n");
goto bail;
@@ -820,33 +1236,50 @@ int main(int argc, char *argv[])
/* DOS kernels want the drive number in BL instead of DL. Indulge them. */
regs.ebx.b[0] = regs.edx.b[0] = drive;
- whichpart = 0; /* Default */
+ /* 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);
+ /* Boot the MBR by default */
+ if (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:
+ * GRLDR of GRUB4DOS wants the partition number in DH:
* -1: whole drive (default)
* 0-3: primary partitions
* 4-*: logical partitions
*/
- regs.edx.b[1] = whichpart-1;
-
- /* 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_sector(0))) {
- error("Cannot read Master Boot Record\n");
- goto bail;
- }
+ regs.edx.b[1] = whichpart - 1;
if (opt.hide) {
if (whichpart < 1 || whichpart > 4)
@@ -855,30 +1288,6 @@ int main(int argc, char *argv[])
error("WARNING: failed to write MBR for 'hide'\n");
}
- if (whichpart == 0) {
- /* Boot the MBR */
-
- partinfo = NULL;
- } else if (whichpart <= 4) {
- /* Boot a primary partition */
-
- partinfo = &((struct part_entry *)(mbr + 0x1be))[whichpart - 1];
- if (partinfo->ostype == 0) {
- error("Invalid primary partition\n");
- goto bail;
- }
- } else {
- /* Boot a logical partition */
-
- nextpart = 5;
- partinfo = find_logical_partition(whichpart, mbr, NULL, NULL);
-
- if (!partinfo || partinfo->ostype == 0) {
- error("Requested logical partition not found\n");
- goto bail;
- }
- }
-
/* Do the actual chainloading */
load_base = opt.seg ? (opt.seg << 4) : 0x7c00;
@@ -926,15 +1335,15 @@ int main(int argc, char *argv[])
goto bail;
}
/* Set it */
- *((uint32_t *) &isolinux_bin[12]) = file_lba;
+ *((uint32_t *) & isolinux_bin[12]) = file_lba;
/* Set boot file length */
- *((uint32_t *) &isolinux_bin[16]) = data[ndata].size;
+ *((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 = (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++;
@@ -956,12 +1365,12 @@ int main(int argc, char *argv[])
}
if (opt.grub) {
- regs.ip = 0x200; /* jump 0x200 bytes into the loadfile */
+ regs.ip = 0x200; /* jump 0x200 bytes into the loadfile */
- /* 0xffffff00 seems to be GRUB ways to record that it's
- "root" is the whole disk (and not a partition). */
- *(uint32_t *) ((unsigned char *) data[ndata].data + 0x208) =
- 0xffffff00ul;
+ /* 0xffffff00 seems to be GRUB ways to record that it's
+ "root" is the whole disk (and not a partition). */
+ *(uint32_t *) ((unsigned char *)data[ndata].data + 0x208) =
+ 0xffffff00ul;
}
ndata++;
@@ -969,29 +1378,32 @@ int main(int argc, char *argv[])
if (!opt.loadfile || data[0].base >= 0x7c00 + SECTOR) {
/* Actually read the boot sector */
- if (!partinfo) {
+ if (!cur_part) {
data[ndata].data = mbr;
- } else if (!(data[ndata].data = read_sector(partinfo->start_lba))) {
+ } 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 &&
- *(uint16_t *)((char *)data[ndata].data +
- data[ndata].size - 2) != 0xaa55) {
- error("Boot sector signature not found (unbootable disk/partition?)\n");
- goto bail;
- }
+ 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 (partinfo && opt.cmldr) {
- memcpy((char *)data[ndata].data+3, cmldr_signature,
+ if (cur_part && opt.cmldr) {
+ memcpy((char *)data[ndata].data + 3, cmldr_signature,
sizeof cmldr_signature);
}
@@ -1000,25 +1412,77 @@ int main(int argc, char *argv[])
* this modifies the field used by FAT and NTFS filesystems, and
* possibly other boot loaders which use the same format.
*/
- if (partinfo && opt.sethidden) {
- *(uint32_t *)((char *)data[ndata].data + 28) =
- partinfo->start_lba;
+ if (cur_part && opt.sethidden) {
+ *(uint32_t *) ((char *)data[ndata].data + 28) = cur_part->lba_data;
}
ndata++;
}
- if (partinfo) {
+ /* Do GPT hand-over, if applicable (as per syslinux/doc/gpt.txt) */
+ if (cur_part && (cur_part->next == next_gpt_part)) {
+ 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' */
+#if DEBUG
+ mbr_part_dump(record);
+ gpt_part_dump((struct gpt_part *)(plen + 1));
+#endif
+ }
+
+ if (cur_part && cur_part->record) {
/* 0x7BE is the canonical place for the first partition entry. */
- data[ndata].data = partinfo;
+ data[ndata].data = (void *)cur_part->record;
data[ndata].base = 0x7be;
- data[ndata].size = sizeof *partinfo;
+ data[ndata].size = sizeof(*cur_part->record);
ndata++;
regs.esi.w[0] = 0x7be;
}
do_boot(data, ndata, &regs);
- bail:
+bail:
+ if (cur_part) {
+ free(cur_part->block);
+ free((void *)cur_part->record);
+ }
+ free(cur_part);
+ free(mbr);
return 255;
}