[PATCH 10/12] partitions: dos: implement partition manipulation support
Sascha Hauer
s.hauer at pengutronix.de
Mon Feb 19 00:31:38 PST 2024
This fills in the msdos specific function hooks to add/remove
partitions.
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
common/partitions/dos.c | 256 ++++++++++++++++++++++++++++++++++++++--
1 file changed, 243 insertions(+), 13 deletions(-)
diff --git a/common/partitions/dos.c b/common/partitions/dos.c
index e5ff59f71a..9bb51bce85 100644
--- a/common/partitions/dos.c
+++ b/common/partitions/dos.c
@@ -15,10 +15,26 @@
#include <common.h>
#include <disks.h>
#include <init.h>
+#include <stdlib.h>
#include <asm/unaligned.h>
#include <linux/err.h>
#include <partitions.h>
+struct dos_partition_desc {
+ struct partition_desc pd;
+ uint32_t signature;
+};
+
+struct dos_partition {
+ struct partition part;
+ bool extended;
+ bool logical;
+
+ uint8_t boot_indicator;
+ uint8_t chs_begin[3];
+ uint8_t type;
+ uint8_t chs_end[3];
+};
enum {
/* These three have identical behaviour; use the second one if DOS FDISK gets
@@ -105,13 +121,14 @@ static int dos_get_disk_signature(struct param_d *p, void *_priv)
return 0;
}
-static void dos_extended_partition(struct block_device *blk, struct partition_desc *pd,
+static void dos_extended_partition(struct block_device *blk, struct dos_partition_desc *dpd,
struct partition *partition, uint32_t signature)
{
uint8_t *buf = malloc(SECTOR_SIZE);
uint32_t ebr_sector = partition->first_sec;
struct partition_entry *table = (struct partition_entry *)&buf[0x1be];
unsigned partno = 5;
+ struct dos_partition *dpart;
struct partition *pentry;
while (1) {
@@ -138,7 +155,14 @@ static void dos_extended_partition(struct block_device *blk, struct partition_de
}
/* /sanity checks */
- pentry = xzalloc(sizeof(*pentry));
+ dpart = xzalloc(sizeof(*dpart));
+ dpart->logical = true;
+ dpart->boot_indicator = table[0].boot_indicator;
+ memcpy(dpart->chs_begin, table[0].chs_begin, sizeof(table[0].chs_begin));
+ dpart->type = table[0].type;
+ memcpy(dpart->chs_end, table[0].chs_end, sizeof(table[0].chs_end));
+
+ pentry = &dpart->part;
/* the first entry defines the extended partition */
pentry->first_sec = ebr_sector +
@@ -150,7 +174,7 @@ static void dos_extended_partition(struct block_device *blk, struct partition_de
sprintf(pentry->partuuid, "%08x-%02u",
signature, partno);
- list_add_tail(&pentry->list, &pd->partitions);
+ list_add_tail(&pentry->list, &dpd->pd.partitions);
partno++;
/* the second entry defines the start of the next ebr if != 0 */
@@ -177,13 +201,14 @@ static void dos_extended_partition(struct block_device *blk, struct partition_de
static struct partition_desc *dos_partition(void *buf, struct block_device *blk)
{
struct partition_entry *table;
+ struct dos_partition *dpart;
struct partition *pentry;
struct partition *extended_partition = NULL;
uint8_t *buffer = buf;
int i;
struct disk_signature_priv *dsp;
uint32_t signature = get_unaligned_le32(buf + 0x1b8);
- struct partition_desc *pd;
+ struct dos_partition_desc *dpd;
if (signature)
sprintf(blk->cdev.diskuuid, "%08x", signature);
@@ -192,8 +217,8 @@ static struct partition_desc *dos_partition(void *buf, struct block_device *blk)
table = (struct partition_entry *)&buffer[446];
- pd = xzalloc(sizeof(*pd));
- INIT_LIST_HEAD(&pd->partitions);
+ dpd = xzalloc(sizeof(*dpd));
+ partition_desc_init(&dpd->pd, blk);
for (i = 0; i < 4; i++) {
uint64_t first_sec = get_unaligned_le32(&table[i].partition_start);
@@ -203,16 +228,26 @@ static struct partition_desc *dos_partition(void *buf, struct block_device *blk)
continue;
}
- pentry = xzalloc(sizeof(*pentry));
+ dpart = xzalloc(sizeof(*dpart));
+ dpart->boot_indicator = table[i].boot_indicator;
+ memcpy(dpart->chs_begin, table[i].chs_begin, sizeof(table[i].chs_begin));
+ dpart->type = table[i].type;
+ memcpy(dpart->chs_end, table[i].chs_end, sizeof(table[i].chs_end));
+
+ pentry = &dpart->part;
pentry->first_sec = first_sec;
pentry->size = get_unaligned_le32(&table[i].partition_size);
pentry->dos_partition_type = table[i].type;
+ pentry->num = i + 1;
- if (signature)
+ if (signature) {
sprintf(pentry->partuuid, "%08x-%02d", signature, i + 1);
+ dpd->signature = signature;
+ }
if (is_extended_partition(pentry)) {
+ dpart->extended = true;
pentry->size = 2;
if (!extended_partition)
@@ -226,11 +261,11 @@ static struct partition_desc *dos_partition(void *buf, struct block_device *blk)
dev_warn(blk->dev, "Skipping additional extended partition\n");
}
- list_add_tail(&pentry->list, &pd->partitions);
+ list_add_tail(&pentry->list, &dpd->pd.partitions);
}
if (extended_partition)
- dos_extended_partition(blk, pd, extended_partition, signature);
+ dos_extended_partition(blk, dpd, extended_partition, signature);
dsp = xzalloc(sizeof(*dsp));
dsp->blk = blk;
@@ -249,23 +284,218 @@ static struct partition_desc *dos_partition(void *buf, struct block_device *blk)
dos_set_disk_signature, dos_get_disk_signature,
&dsp->signature, "%08x", dsp);
- return pd;
+ return &dpd->pd;
}
static void dos_partition_free(struct partition_desc *pd)
{
struct partition *part, *tmp;
- list_for_each_entry_safe(part, tmp, &pd->partitions, list)
- free(part);
+ list_for_each_entry_safe(part, tmp, &pd->partitions, list) {
+ struct dos_partition *dpart = container_of(part, struct dos_partition, part);
+
+ free(dpart);
+ }
free(pd);
}
+static __maybe_unused struct partition_desc *dos_partition_create_table(struct block_device *blk)
+{
+ struct dos_partition_desc *dpd = xzalloc(512);
+
+ partition_desc_init(&dpd->pd, blk);
+
+ dpd->signature = random32();
+
+ return &dpd->pd;
+}
+
+static int fs_type_to_type(const char *fstype)
+{
+ unsigned long type;
+ int ret;
+
+ if (!strcmp(fstype, "ext2"))
+ return 0x83;
+ if (!strcmp(fstype, "ext3"))
+ return 0x83;
+ if (!strcmp(fstype, "ext4"))
+ return 0x83;
+ if (!strcmp(fstype, "fat16"))
+ return 0xe;
+ if (!strcmp(fstype, "fat32"))
+ return 0xc;
+
+ ret = kstrtoul(fstype, 16, &type);
+ if (ret)
+ return ret;
+
+ if (type > 0xff)
+ return -EINVAL;
+
+ return type;
+}
+
+static __maybe_unused int dos_partition_mkpart(struct partition_desc *pd,
+ const char *name, const char *fs_type,
+ uint64_t start_lba, uint64_t end_lba)
+{
+ struct dos_partition *dpart;
+ struct partition *part, *part_extended = NULL;
+ int npart = 0, npart_logical = 0;
+ uint64_t size;
+ int mask_free = 0xf;
+ int type = fs_type_to_type(fs_type);
+
+ if (type < 0) {
+ pr_err("invalid fs_type \"%s\"\n", fs_type);
+ return -EINVAL;
+ }
+
+ if (start_lba < 1) {
+ pr_err("invalid start LBA, minimum is 1\n");
+ return -EINVAL;
+ }
+
+ list_for_each_entry(part, &pd->partitions, list) {
+ dpart = container_of(part, struct dos_partition, part);
+
+ mask_free &= ~(1 << npart);
+
+ if (dpart->extended)
+ part_extended = part;
+ if (dpart->logical)
+ npart_logical++;
+ else
+ npart++;
+ }
+
+ if (!strcmp(name, "extended")) {
+ if (part_extended) {
+ pr_err("extended partition already exists\n");
+ return -ENOSPC;
+ }
+ goto create;
+ } else if (!strcmp(name, "primary")) {
+ if (npart == 4) {
+ pr_err("Can't create any more partitions\n");
+ return -ENOSPC;
+ }
+
+ goto create;
+ } else if (!strcmp(name, "logical")) {
+ if (!part_extended) {
+ pr_err("No extended partition\n");
+ return -EINVAL;
+ }
+
+ if (npart_logical >= 4) {
+ pr_err("Can't create any more partitions\n");
+ return -ENOSPC;
+ }
+
+ pr_err("Can't create logical partitions yet\n");
+ return -EINVAL;
+ } else {
+ pr_err("Invalid name \"%s\"\n", name);
+ return -EINVAL;
+ }
+
+ return 0;
+
+create:
+ dpart = xzalloc(sizeof(*dpart));
+ part = &dpart->part;
+
+ if (start_lba > UINT_MAX)
+ return -ENOSPC;
+ size = end_lba - start_lba + 1;
+
+ if (size > UINT_MAX)
+ return -ENOSPC;
+
+ dpart->type = fs_type_to_type(fs_type);
+
+ part->first_sec = start_lba;
+ part->size = size;
+ part->num = ffs(mask_free);
+
+ list_add_tail(&part->list, &pd->partitions);
+
+ return 0;
+}
+
+static __maybe_unused int dos_partition_rmpart(struct partition_desc *pd, struct partition *part)
+{
+ struct dos_partition *dpart = container_of(part, struct dos_partition, part);
+
+ list_del(&part->list);
+ free(dpart);
+
+ return 0;
+}
+
+static __maybe_unused int dos_partition_write(struct partition_desc *pd)
+{
+ struct dos_partition_desc *dpd = container_of(pd, struct dos_partition_desc, pd);
+ struct dos_partition *dpart;
+ struct partition *part;
+ void *buf;
+ struct partition_entry *table, *entry;
+ int ret;
+
+ list_for_each_entry(part, &pd->partitions, list) {
+ dpart = container_of(part, struct dos_partition, part);
+ if (dpart->logical) {
+ pr_err("Cannot write tables with logical partitions yet\n");
+ return -EINVAL;
+ }
+ }
+
+ buf = read_mbr(pd->blk);
+ if (!buf)
+ return -EIO;
+
+ put_unaligned_le32(dpd->signature, buf + 0x1b8);
+
+ table = buf + 0x1be;
+ memset(table, 0x0, sizeof(*table) * 4);
+
+ *(u8 *)(buf + 0x1fe) = 0x55;
+ *(u8 *)(buf + 0x1ff) = 0xaa;
+
+ list_for_each_entry(part, &pd->partitions, list) {
+ dpart = container_of(part, struct dos_partition, part);
+
+ entry = &table[part->num - 1];
+
+ entry->boot_indicator = dpart->boot_indicator;
+ memcpy(entry->chs_begin, dpart->chs_begin, sizeof(entry->chs_begin));
+ entry->type = dpart->type;
+ memcpy(entry->chs_end, dpart->chs_end, sizeof(entry->chs_end));
+ put_unaligned_le32(part->first_sec, &entry->partition_start);
+ put_unaligned_le32(part->size, &entry->partition_size);
+ }
+
+ ret = block_write(pd->blk, buf, 0, 1);
+
+ free(buf);
+
+ return ret;
+}
+
static struct partition_parser dos = {
.parse = dos_partition,
.partition_free = dos_partition_free,
+#ifdef CONFIG_PARTITION_MANIPULATION
+ .create = dos_partition_create_table,
+ .mkpart = dos_partition_mkpart,
+ .rmpart = dos_partition_rmpart,
+ .write = dos_partition_write,
+#endif
.type = filetype_mbr,
+ .name = "msdos",
};
static int dos_partition_init(void)
--
2.39.2
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