u-boot/disk/part_dos.c
Marek Szyprowski 20bd5ac6e4 disk: dos: add code for creating MBR partition layout
Add a code for creating and writing MBR partition layout. The code generates
similar layout of EBRs (Exteneded Block Records) and logical volumes as
Linux's fdisk utility.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
2021-01-15 15:33:09 -05:00

514 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2001
* Raymond Lo, lo@routefree.com
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*/
/*
* Support for harddisk partitions.
*
* To be compatible with LinuxPPC and Apple we use the standard Apple
* SCSI disk partitioning scheme. For more information see:
* http://developer.apple.com/techpubs/mac/Devices/Devices-126.html#MARKER-14-92
*/
#include <common.h>
#include <blk.h>
#include <command.h>
#include <ide.h>
#include <memalign.h>
#include <asm/unaligned.h>
#include <linux/compiler.h>
#include "part_dos.h"
#include <part.h>
#ifdef CONFIG_HAVE_BLOCK_DEVICE
#define DOS_PART_DEFAULT_SECTOR 512
/* should this be configurable? It looks like it's not very common at all
* to use large numbers of partitions */
#define MAX_EXT_PARTS 256
static inline int is_extended(int part_type)
{
return (part_type == DOS_PART_TYPE_EXTENDED ||
part_type == DOS_PART_TYPE_EXTENDED_LBA ||
part_type == DOS_PART_TYPE_EXTENDED_LINUX);
}
static int get_bootable(dos_partition_t *p)
{
int ret = 0;
if (p->sys_ind == 0xef)
ret |= PART_EFI_SYSTEM_PARTITION;
if (p->boot_ind == 0x80)
ret |= PART_BOOTABLE;
return ret;
}
static void print_one_part(dos_partition_t *p, lbaint_t ext_part_sector,
int part_num, unsigned int disksig)
{
lbaint_t lba_start = ext_part_sector + get_unaligned_le32(p->start4);
lbaint_t lba_size = get_unaligned_le32(p->size4);
printf("%3d\t%-10" LBAFlength "u\t%-10" LBAFlength
"u\t%08x-%02x\t%02x%s%s\n",
part_num, lba_start, lba_size, disksig, part_num, p->sys_ind,
(is_extended(p->sys_ind) ? " Extd" : ""),
(get_bootable(p) ? " Boot" : ""));
}
static int test_block_type(unsigned char *buffer)
{
int slot;
struct dos_partition *p;
int part_count = 0;
if((buffer[DOS_PART_MAGIC_OFFSET + 0] != 0x55) ||
(buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) ) {
return (-1);
} /* no DOS Signature at all */
p = (struct dos_partition *)&buffer[DOS_PART_TBL_OFFSET];
/* Check that the boot indicators are valid and count the partitions. */
for (slot = 0; slot < 4; ++slot, ++p) {
if (p->boot_ind != 0 && p->boot_ind != 0x80)
break;
if (p->sys_ind)
++part_count;
}
/*
* If the partition table is invalid or empty,
* check if this is a DOS PBR
*/
if (slot != 4 || !part_count) {
if (!strncmp((char *)&buffer[DOS_PBR_FSTYPE_OFFSET],
"FAT", 3) ||
!strncmp((char *)&buffer[DOS_PBR32_FSTYPE_OFFSET],
"FAT32", 5))
return DOS_PBR; /* This is a DOS PBR and not an MBR */
}
if (slot == 4)
return DOS_MBR; /* This is an DOS MBR */
/* This is neither a DOS MBR nor a DOS PBR */
return -1;
}
static int part_test_dos(struct blk_desc *dev_desc)
{
#ifndef CONFIG_SPL_BUILD
ALLOC_CACHE_ALIGN_BUFFER(legacy_mbr, mbr,
DIV_ROUND_UP(dev_desc->blksz, sizeof(legacy_mbr)));
if (blk_dread(dev_desc, 0, 1, (ulong *)mbr) != 1)
return -1;
if (test_block_type((unsigned char *)mbr) != DOS_MBR)
return -1;
if (dev_desc->sig_type == SIG_TYPE_NONE &&
mbr->unique_mbr_signature != 0) {
dev_desc->sig_type = SIG_TYPE_MBR;
dev_desc->mbr_sig = mbr->unique_mbr_signature;
}
#else
ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
if (blk_dread(dev_desc, 0, 1, (ulong *)buffer) != 1)
return -1;
if (test_block_type(buffer) != DOS_MBR)
return -1;
#endif
return 0;
}
/* Print a partition that is relative to its Extended partition table
*/
static void print_partition_extended(struct blk_desc *dev_desc,
lbaint_t ext_part_sector,
lbaint_t relative,
int part_num, unsigned int disksig)
{
ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
dos_partition_t *pt;
int i;
/* set a maximum recursion level */
if (part_num > MAX_EXT_PARTS)
{
printf("** Nested DOS partitions detected, stopping **\n");
return;
}
if (blk_dread(dev_desc, ext_part_sector, 1, (ulong *)buffer) != 1) {
printf ("** Can't read partition table on %d:" LBAFU " **\n",
dev_desc->devnum, ext_part_sector);
return;
}
i=test_block_type(buffer);
if (i != DOS_MBR) {
printf ("bad MBR sector signature 0x%02x%02x\n",
buffer[DOS_PART_MAGIC_OFFSET],
buffer[DOS_PART_MAGIC_OFFSET + 1]);
return;
}
if (!ext_part_sector)
disksig = get_unaligned_le32(&buffer[DOS_PART_DISKSIG_OFFSET]);
/* Print all primary/logical partitions */
pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
for (i = 0; i < 4; i++, pt++) {
/*
* fdisk does not show the extended partitions that
* are not in the MBR
*/
if ((pt->sys_ind != 0) &&
(ext_part_sector == 0 || !is_extended (pt->sys_ind)) ) {
print_one_part(pt, ext_part_sector, part_num, disksig);
}
/* Reverse engr the fdisk part# assignment rule! */
if ((ext_part_sector == 0) ||
(pt->sys_ind != 0 && !is_extended (pt->sys_ind)) ) {
part_num++;
}
}
/* Follows the extended partitions */
pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
for (i = 0; i < 4; i++, pt++) {
if (is_extended (pt->sys_ind)) {
lbaint_t lba_start
= get_unaligned_le32 (pt->start4) + relative;
print_partition_extended(dev_desc, lba_start,
ext_part_sector == 0 ? lba_start : relative,
part_num, disksig);
}
}
return;
}
/* Print a partition that is relative to its Extended partition table
*/
static int part_get_info_extended(struct blk_desc *dev_desc,
lbaint_t ext_part_sector, lbaint_t relative,
int part_num, int which_part,
struct disk_partition *info, uint disksig)
{
ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
dos_partition_t *pt;
int i;
int dos_type;
/* set a maximum recursion level */
if (part_num > MAX_EXT_PARTS)
{
printf("** Nested DOS partitions detected, stopping **\n");
return -1;
}
if (blk_dread(dev_desc, ext_part_sector, 1, (ulong *)buffer) != 1) {
printf ("** Can't read partition table on %d:" LBAFU " **\n",
dev_desc->devnum, ext_part_sector);
return -1;
}
if (buffer[DOS_PART_MAGIC_OFFSET] != 0x55 ||
buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) {
printf ("bad MBR sector signature 0x%02x%02x\n",
buffer[DOS_PART_MAGIC_OFFSET],
buffer[DOS_PART_MAGIC_OFFSET + 1]);
return -1;
}
#if CONFIG_IS_ENABLED(PARTITION_UUIDS)
if (!ext_part_sector)
disksig = get_unaligned_le32(&buffer[DOS_PART_DISKSIG_OFFSET]);
#endif
/* Print all primary/logical partitions */
pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
for (i = 0; i < 4; i++, pt++) {
/*
* fdisk does not show the extended partitions that
* are not in the MBR
*/
if (((pt->boot_ind & ~0x80) == 0) &&
(pt->sys_ind != 0) &&
(part_num == which_part) &&
(ext_part_sector == 0 || is_extended(pt->sys_ind) == 0)) {
info->blksz = DOS_PART_DEFAULT_SECTOR;
info->start = (lbaint_t)(ext_part_sector +
get_unaligned_le32(pt->start4));
info->size = (lbaint_t)get_unaligned_le32(pt->size4);
part_set_generic_name(dev_desc, part_num,
(char *)info->name);
/* sprintf(info->type, "%d, pt->sys_ind); */
strcpy((char *)info->type, "U-Boot");
info->bootable = get_bootable(pt);
#if CONFIG_IS_ENABLED(PARTITION_UUIDS)
sprintf(info->uuid, "%08x-%02x", disksig, part_num);
#endif
info->sys_ind = pt->sys_ind;
return 0;
}
/* Reverse engr the fdisk part# assignment rule! */
if ((ext_part_sector == 0) ||
(pt->sys_ind != 0 && !is_extended (pt->sys_ind)) ) {
part_num++;
}
}
/* Follows the extended partitions */
pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
for (i = 0; i < 4; i++, pt++) {
if (is_extended (pt->sys_ind)) {
lbaint_t lba_start
= get_unaligned_le32 (pt->start4) + relative;
return part_get_info_extended(dev_desc, lba_start,
ext_part_sector == 0 ? lba_start : relative,
part_num, which_part, info, disksig);
}
}
/* Check for DOS PBR if no partition is found */
dos_type = test_block_type(buffer);
if (dos_type == DOS_PBR) {
info->start = 0;
info->size = dev_desc->lba;
info->blksz = DOS_PART_DEFAULT_SECTOR;
info->bootable = 0;
strcpy((char *)info->type, "U-Boot");
#if CONFIG_IS_ENABLED(PARTITION_UUIDS)
info->uuid[0] = 0;
#endif
return 0;
}
return -1;
}
static void __maybe_unused part_print_dos(struct blk_desc *dev_desc)
{
printf("Part\tStart Sector\tNum Sectors\tUUID\t\tType\n");
print_partition_extended(dev_desc, 0, 0, 1, 0);
}
static int __maybe_unused part_get_info_dos(struct blk_desc *dev_desc, int part,
struct disk_partition *info)
{
return part_get_info_extended(dev_desc, 0, 0, 1, part, info, 0);
}
int is_valid_dos_buf(void *buf)
{
return test_block_type(buf) == DOS_MBR ? 0 : -1;
}
#if CONFIG_IS_ENABLED(CMD_MBR)
static void lba_to_chs(lbaint_t lba, unsigned char *rc, unsigned char *rh,
unsigned char *rs)
{
unsigned int c, h, s;
/* use fixed CHS geometry */
unsigned int sectpertrack = 63;
unsigned int heads = 255;
c = (lba + 1) / sectpertrack / heads;
h = (lba + 1) / sectpertrack - c * heads;
s = (lba + 1) - (c * heads + h) * sectpertrack;
if (c > 1023) {
c = 1023;
h = 254;
s = 63;
}
*rc = c & 0xff;
*rh = h;
*rs = s + ((c & 0x300) >> 2);
}
static void mbr_fill_pt_entry(dos_partition_t *pt, lbaint_t start,
lbaint_t relative, lbaint_t size, uchar sys_ind, bool bootable)
{
pt->boot_ind = bootable ? 0x80 : 0x00;
pt->sys_ind = sys_ind;
lba_to_chs(start, &pt->cyl, &pt->head, &pt->sector);
lba_to_chs(start + size - 1, &pt->end_cyl, &pt->end_head, &pt->end_sector);
put_unaligned_le32(relative, &pt->start4);
put_unaligned_le32(size, &pt->size4);
}
int write_mbr_partitions(struct blk_desc *dev,
struct disk_partition *p, int count, unsigned int disksig)
{
ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev->blksz);
lbaint_t ext_part_start = 0, ext_part_size = 0, ext_part_sect = 0;
dos_partition_t *pt;
int i;
memset(buffer, 0, dev->blksz);
buffer[DOS_PART_MAGIC_OFFSET] = 0x55;
buffer[DOS_PART_MAGIC_OFFSET + 1] = 0xaa;
put_unaligned_le32(disksig, &buffer[DOS_PART_DISKSIG_OFFSET]);
pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
/* create all primary partitions */
for (i = 0; i < 4 && i < count; i++, pt++) {
mbr_fill_pt_entry(pt, p[i].start, p[i].start, p[i].size,
p[i].sys_ind, p[i].bootable);
if (is_extended(p[i].sys_ind)) {
ext_part_start = p[i].start;
ext_part_size = p[i].size;
ext_part_sect = p[i].start;
}
}
if (i < count && !ext_part_start) {
printf("%s: extended partition is needed for more than 4 partitions\n",
__func__);
return -1;
}
/* write MBR */
if (blk_dwrite(dev, 0, 1, buffer) != 1) {
printf("%s: failed writing 'MBR' (1 blks at 0x0)\n",
__func__);
return -1;
}
/* create extended volumes */
for (; i < count; i++) {
lbaint_t next_ebr = 0;
memset(buffer, 0, dev->blksz);
buffer[DOS_PART_MAGIC_OFFSET] = 0x55;
buffer[DOS_PART_MAGIC_OFFSET + 1] = 0xaa;
pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
mbr_fill_pt_entry(pt, p[i].start, p[i].start - ext_part_sect,
p[i].size, p[i].sys_ind, p[i].bootable);
if (i + 1 < count) {
pt++;
next_ebr = p[i].start + p[i].size;
mbr_fill_pt_entry(pt, next_ebr,
next_ebr - ext_part_start,
p[i+1].start + p[i+1].size - next_ebr,
DOS_PART_TYPE_EXTENDED, 0);
}
/* write EBR */
if (blk_dwrite(dev, ext_part_sect, 1, buffer) != 1) {
printf("%s: failed writing 'EBR' (1 blks at 0x%lx)\n",
__func__, ext_part_sect);
return -1;
}
ext_part_sect = next_ebr;
}
return 0;
}
int layout_mbr_partitions(struct disk_partition *p, int count,
lbaint_t total_sectors)
{
struct disk_partition *ext = NULL;
int i, j;
lbaint_t ext_vol_start;
/* calculate primary partitions start and size if needed */
if (!p[0].start)
p[0].start = DOS_PART_DEFAULT_GAP;
for (i = 0; i < 4 && i < count; i++) {
if (!p[i].start)
p[i].start = p[i - 1].start + p[i - 1].size;
if (!p[i].size) {
lbaint_t end = total_sectors;
lbaint_t allocated = 0;
for (j = i + 1; j < 4 && j < count; j++) {
if (p[j].start) {
end = p[j].start;
break;
}
allocated += p[j].size;
}
p[i].size = end - allocated - p[i].start;
}
if (p[i].sys_ind == 0x05)
ext = &p[i];
}
if (i >= 4 && !ext) {
printf("%s: extended partition is needed for more than 4 partitions\n",
__func__);
return -1;
}
/* calculate extended volumes start and size if needed */
ext_vol_start = ext->start;
for (i = 4; i < count; i++) {
if (!p[i].start)
p[i].start = ext_vol_start + DOS_PART_DEFAULT_GAP;
if (!p[i].size) {
lbaint_t end = ext->start + ext->size;
lbaint_t allocated = 0;
for (j = i + 1; j < count; j++) {
if (p[j].start) {
end = p[j].start - DOS_PART_DEFAULT_GAP;
break;
}
allocated += p[j].size + DOS_PART_DEFAULT_GAP;
}
p[i].size = end - allocated - p[i].start;
}
ext_vol_start = p[i].start + p[i].size;
}
return 0;
}
#endif
int write_mbr_sector(struct blk_desc *dev_desc, void *buf)
{
if (is_valid_dos_buf(buf))
return -1;
/* write MBR */
if (blk_dwrite(dev_desc, 0, 1, buf) != 1) {
printf("%s: failed writing '%s' (1 blks at 0x0)\n",
__func__, "MBR");
return 1;
}
return 0;
}
U_BOOT_PART_TYPE(dos) = {
.name = "DOS",
.part_type = PART_TYPE_DOS,
.max_entries = DOS_ENTRY_NUMBERS,
.get_info = part_get_info_ptr(part_get_info_dos),
.print = part_print_ptr(part_print_dos),
.test = part_test_dos,
};
#endif