platform_system_core/gpttool/gpttool.c

374 lines
7.2 KiB
C

/*
** Copyright 2011, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <unistd.h>
#include <zlib.h>
#include <linux/fs.h>
typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned int u32;
typedef unsigned long long u64;
const u8 partition_type_uuid[16] = {
0xa2, 0xa0, 0xd0, 0xeb, 0xe5, 0xb9, 0x33, 0x44,
0x87, 0xc0, 0x68, 0xb6, 0xb7, 0x26, 0x99, 0xc7,
};
#define EFI_VERSION 0x00010000
#define EFI_MAGIC "EFI PART"
#define EFI_ENTRIES 128
#define EFI_NAMELEN 36
struct efi_header {
u8 magic[8];
u32 version;
u32 header_sz;
u32 crc32;
u32 reserved;
u64 header_lba;
u64 backup_lba;
u64 first_lba;
u64 last_lba;
u8 volume_uuid[16];
u64 entries_lba;
u32 entries_count;
u32 entries_size;
u32 entries_crc32;
} __attribute__((packed));
struct efi_entry {
u8 type_uuid[16];
u8 uniq_uuid[16];
u64 first_lba;
u64 last_lba;
u64 attr;
u16 name[EFI_NAMELEN];
};
struct ptable {
u8 mbr[512];
union {
struct efi_header header;
u8 block[512];
};
struct efi_entry entry[EFI_ENTRIES];
};
void get_uuid(u8 *uuid)
{
int fd;
fd = open("/dev/urandom", O_RDONLY);
read(fd, uuid, 16);
close(fd);
}
void init_mbr(u8 *mbr, u32 blocks)
{
mbr[0x1be] = 0x00; // nonbootable
mbr[0x1bf] = 0xFF; // bogus CHS
mbr[0x1c0] = 0xFF;
mbr[0x1c1] = 0xFF;
mbr[0x1c2] = 0xEE; // GPT partition
mbr[0x1c3] = 0xFF; // bogus CHS
mbr[0x1c4] = 0xFF;
mbr[0x1c5] = 0xFF;
mbr[0x1c6] = 0x01; // start
mbr[0x1c7] = 0x00;
mbr[0x1c8] = 0x00;
mbr[0x1c9] = 0x00;
memcpy(mbr + 0x1ca, &blocks, sizeof(u32));
mbr[0x1fe] = 0x55;
mbr[0x1ff] = 0xaa;
}
int add_ptn(struct ptable *ptbl, u64 first, u64 last, const char *name)
{
struct efi_header *hdr = &ptbl->header;
struct efi_entry *entry = ptbl->entry;
unsigned n;
if (first < 34) {
fprintf(stderr,"partition '%s' overlaps partition table\n", name);
return -1;
}
if (last > hdr->last_lba) {
fprintf(stderr,"partition '%s' does not fit on disk\n", name);
return -1;
}
for (n = 0; n < EFI_ENTRIES; n++, entry++) {
if (entry->type_uuid[0])
continue;
memcpy(entry->type_uuid, partition_type_uuid, 16);
get_uuid(entry->uniq_uuid);
entry->first_lba = first;
entry->last_lba = last;
for (n = 0; (n < EFI_NAMELEN) && *name; n++)
entry->name[n] = *name++;
return 0;
}
fprintf(stderr,"out of partition table entries\n");
return -1;
}
int usage(void)
{
fprintf(stderr,
"usage: gpttool write <disk> [ <partition> ]*\n"
" gpttool read <disk>\n"
" gpttool test [ <partition> ]*\n"
"\n"
"partition: [<name>]:<size>[kmg] | @<file-of-partitions>\n"
);
return 0;
}
void show(struct ptable *ptbl)
{
struct efi_entry *entry = ptbl->entry;
unsigned n, m;
char name[EFI_NAMELEN + 1];
fprintf(stderr,"ptn start block end block name\n");
fprintf(stderr,"---- ------------- ------------- --------------------\n");
for (n = 0; n < EFI_ENTRIES; n++, entry++) {
if (entry->type_uuid[0] == 0)
break;
for (m = 0; m < EFI_NAMELEN; m++) {
name[m] = entry->name[m] & 127;
}
name[m] = 0;
fprintf(stderr,"#%03d %13lld %13lld %s\n",
n + 1, entry->first_lba, entry->last_lba, name);
}
}
u64 find_next_lba(struct ptable *ptbl)
{
struct efi_entry *entry = ptbl->entry;
unsigned n;
u64 a = 0;
for (n = 0; n < EFI_ENTRIES; n++, entry++) {
if ((entry->last_lba + 1) > a)
a = entry->last_lba + 1;
}
return a;
}
u64 next_lba = 0;
u64 parse_size(char *sz)
{
int l = strlen(sz);
u64 n = strtoull(sz, 0, 10);
if (l) {
switch(sz[l-1]){
case 'k':
case 'K':
n *= 1024;
break;
case 'm':
case 'M':
n *= (1024 * 1024);
break;
case 'g':
case 'G':
n *= (1024 * 1024 * 1024);
break;
}
}
return n;
}
int parse_ptn(struct ptable *ptbl, char *x)
{
char *y = strchr(x, ':');
u64 sz;
if (!y) {
fprintf(stderr,"invalid partition entry: %s\n", x);
return -1;
}
*y++ = 0;
if (*y == 0) {
sz = ptbl->header.last_lba - next_lba;
} else {
sz = parse_size(y);
if (sz & 511) {
fprintf(stderr,"partition size must be multiple of 512\n");
return -1;
}
sz /= 512;
}
if (sz == 0) {
fprintf(stderr,"zero size partitions not allowed\n");
return -1;
}
if (x[0] && add_ptn(ptbl, next_lba, next_lba + sz - 1, x))
return -1;
next_lba = next_lba + sz;
return 0;
}
int main(int argc, char **argv)
{
struct ptable ptbl;
struct efi_header *hdr = &ptbl.header;
u32 n;
u64 sz;
int fd;
const char *device;
int real_disk = 0;
if (argc < 2)
return usage();
if (!strcmp(argv[1], "write")) {
if (argc < 3)
return usage();
device = argv[2];
argc -= 2;
argv += 2;
real_disk = 1;
} else if (!strcmp(argv[1], "test")) {
argc -= 1;
argv += 1;
real_disk = 0;
sz = 2097152 * 16;
fprintf(stderr,"< simulating 16GB disk >\n\n");
} else {
return usage();
}
if (real_disk) {
if (!strcmp(device, "/dev/sda") ||
!strcmp(device, "/dev/sdb")) {
fprintf(stderr,"error: refusing to partition sda or sdb\n");
return -1;
}
fd = open(device, O_RDWR);
if (fd < 0) {
fprintf(stderr,"error: cannot open '%s'\n", device);
return -1;
}
if (ioctl(fd, BLKGETSIZE64, &sz)) {
fprintf(stderr,"error: cannot query block device size\n");
return -1;
}
sz /= 512;
fprintf(stderr,"blocks %lld\n", sz);
}
memset(&ptbl, 0, sizeof(ptbl));
init_mbr(ptbl.mbr, sz - 1);
memcpy(hdr->magic, EFI_MAGIC, sizeof(hdr->magic));
hdr->version = EFI_VERSION;
hdr->header_sz = sizeof(struct efi_header);
hdr->header_lba = 1;
hdr->backup_lba = sz - 1;
hdr->first_lba = 34;
hdr->last_lba = sz - 1;
get_uuid(hdr->volume_uuid);
hdr->entries_lba = 2;
hdr->entries_count = 128;
hdr->entries_size = sizeof(struct efi_entry);
while (argc > 1) {
if (argv[1][0] == '@') {
char line[256], *p;
FILE *f;
f = fopen(argv[1] + 1, "r");
if (!f) {
fprintf(stderr,"cannot read partitions from '%s\n", argv[1]);
return -1;
}
while (fgets(line, sizeof(line), f)) {
p = line + strlen(line);
while (p > line) {
p--;
if (*p > ' ')
break;
*p = 0;
}
p = line;
while (*p && (*p <= ' '))
p++;
if (*p == '#')
continue;
if (*p == 0)
continue;
if (parse_ptn(&ptbl, p))
return -1;
}
fclose(f);
} else {
if (parse_ptn(&ptbl, argv[1]))
return -1;
}
argc--;
argv++;
}
n = crc32(0, Z_NULL, 0);
n = crc32(n, (void*) ptbl.entry, sizeof(ptbl.entry));
hdr->entries_crc32 = n;
n = crc32(0, Z_NULL, 0);
n = crc32(n, (void*) &ptbl.header, sizeof(ptbl.header));
hdr->crc32 = n;
show(&ptbl);
if (real_disk) {
write(fd, &ptbl, sizeof(ptbl));
fsync(fd);
if (ioctl(fd, BLKRRPART, 0)) {
fprintf(stderr,"could not re-read partition table\n");
}
close(fd);
}
return 0;
}