[PATCH 11/12] partitions: efi: implement partition manipulation support
Sascha Hauer
s.hauer at pengutronix.de
Mon Feb 19 00:31:39 PST 2024
This fills in the partition manipulation function hooks to add/remove
efi (GPT) partitions and to write a GPT partition table. This depends on
te msdos partition writing support for generating a protective MBR.
Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
---
common/partitions/Kconfig | 1 +
common/partitions/efi.c | 277 ++++++++++++++++++++++++++++++++++++--
2 files changed, 265 insertions(+), 13 deletions(-)
diff --git a/common/partitions/Kconfig b/common/partitions/Kconfig
index 7f12383082..3bbcceedc1 100644
--- a/common/partitions/Kconfig
+++ b/common/partitions/Kconfig
@@ -19,6 +19,7 @@ config PARTITION_DISK_EFI
depends on PARTITION_DISK
select CRC32
select PRINTF_UUID
+ select PARTITION_DISK_DOS if PARTITION_MANIPULATION
bool "EFI: GPT partition support"
help
Add support to handle partitions in GUID Partition Table style.
diff --git a/common/partitions/efi.c b/common/partitions/efi.c
index 407c1a4d08..67d4978244 100644
--- a/common/partitions/efi.c
+++ b/common/partitions/efi.c
@@ -23,13 +23,14 @@
#include <partitions.h>
struct efi_partition_desc {
- struct partition_desc pd; /* must be first */
- gpt_header gpt;
+ struct partition_desc pd;
+ gpt_header *gpt;
+ gpt_entry *ptes;
};
struct efi_partition {
- struct partition part; /* must be first */
- gpt_entry pte;
+ struct partition part;
+ gpt_entry *pte;
};
static const int force_gpt = IS_ENABLED(CONFIG_PARTITION_DISK_EFI_GPT_NO_FORCE);
@@ -90,6 +91,7 @@ static gpt_entry *alloc_read_gpt_entries(struct block_device *blk,
if (!count)
return NULL;
+
pte = kzalloc(count, GFP_KERNEL);
if (!pte)
return NULL;
@@ -216,7 +218,8 @@ static int is_gpt_valid(struct block_device *blk, u64 lba,
le32_to_cpu((*gpt)->sizeof_partition_entry));
if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) {
- dev_dbg(blk->dev, "GUID Partitition Entry Array CRC check failed.\n");
+ dev_dbg(blk->dev, "GUID Partitition Entry Array CRC check failed: 0x%08x 0x%08x\n",
+ crc, le32_to_cpu((*gpt)->partition_entry_array_crc32));
goto fail_ptes;
}
@@ -441,6 +444,19 @@ static void part_set_efi_name(gpt_entry *pte, char *dest)
dest[i] = 0;
}
+static void part_get_efi_name(gpt_entry *pte, const char *src)
+{
+ int i;
+ int len = strlen(src);
+
+ for (i = 0; i < GPT_PARTNAME_MAX_SIZE ; i++) {
+ if (i <= len)
+ pte->partition_name[i] = src[i];
+ else
+ pte->partition_name[i] = 0;
+ }
+}
+
static struct partition_desc *efi_partition(void *buf, struct block_device *blk)
{
gpt_header *gpt = NULL;
@@ -468,8 +484,10 @@ static struct partition_desc *efi_partition(void *buf, struct block_device *blk)
}
epd = xzalloc(sizeof(*epd));
- INIT_LIST_HEAD(&epd->pd.partitions);
- epd->gpt = *gpt;
+ partition_desc_init(&epd->pd, blk);
+
+ epd->gpt = gpt;
+ epd->ptes = ptes;
for (i = 0; i < nb_part; i++) {
if (!is_pte_valid(&ptes[i], last_lba(blk))) {
@@ -478,6 +496,7 @@ static struct partition_desc *efi_partition(void *buf, struct block_device *blk)
}
epart = xzalloc(sizeof(*epart));
+ epart->pte = &ptes[i];
pentry = &epart->part;
pentry->first_sec = le64_to_cpu(ptes[i].starting_lba);
pentry->size = le64_to_cpu(ptes[i].ending_lba) - pentry->first_sec;
@@ -485,30 +504,262 @@ static struct partition_desc *efi_partition(void *buf, struct block_device *blk)
part_set_efi_name(&ptes[i], pentry->name);
snprintf(pentry->partuuid, sizeof(pentry->partuuid), "%pUl", &ptes[i].unique_partition_guid);
pentry->typeuuid = ptes[i].partition_type_guid;
- pentry->num = i;
+ pentry->num = i + 1;
list_add_tail(&pentry->list, &epd->pd.partitions);
}
out:
- kfree(gpt);
- kfree(ptes);
return &epd->pd;
}
static void efi_partition_free(struct partition_desc *pd)
{
+ struct efi_partition_desc *epd = container_of(pd, struct efi_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 efi_partition *epart = container_of(part, struct efi_partition, part);
+
+ free(epart);
+ }
+
+ free(epd->ptes);
+ free(epd->gpt);
+ free(epd);
+}
+
+static __maybe_unused struct partition_desc *efi_partition_create_table(struct block_device *blk)
+{
+ struct efi_partition_desc *epd = xzalloc(sizeof(*epd));
+ gpt_header *gpt;
+
+ partition_desc_init(&epd->pd, blk);
+
+ epd->gpt = xzalloc(512);
+ gpt = epd->gpt;
+
+ gpt->signature = cpu_to_le64(GPT_HEADER_SIGNATURE);
+ gpt->revision = cpu_to_le32(0x100);
+ gpt->header_size = cpu_to_le32(sizeof(*gpt));
+ gpt->my_lba = cpu_to_le64(1);
+ gpt->alternate_lba = cpu_to_le64(last_lba(blk));
+ gpt->first_usable_lba = cpu_to_le64(34);
+ gpt->last_usable_lba = cpu_to_le64(last_lba(blk) - 34);;
+ generate_random_guid((unsigned char *)&gpt->disk_guid);
+ gpt->partition_entry_lba = cpu_to_le64(2);
+ gpt->num_partition_entries = cpu_to_le32(128);
+ gpt->sizeof_partition_entry = cpu_to_le32(sizeof(gpt_entry));
+
+ pr_info("Created new disk label with GUID %pU\n", &gpt->disk_guid);
+
+ epd->ptes = xzalloc(128 * sizeof(gpt_entry));
+
+ return &epd->pd;
+}
+
+static guid_t partition_linux_data_guid = PARTITION_LINUX_DATA_GUID;
+static guid_t partition_basic_data_guid = PARTITION_BASIC_DATA_GUID;
+
+static const guid_t *fs_type_to_guid(const char *fstype)
+{
+ if (!strcmp(fstype, "ext2"))
+ return &partition_linux_data_guid;
+ if (!strcmp(fstype, "ext3"))
+ return &partition_linux_data_guid;
+ if (!strcmp(fstype, "ext4"))
+ return &partition_linux_data_guid;
+ if (!strcmp(fstype, "fat16"))
+ return &partition_basic_data_guid;
+ if (!strcmp(fstype, "fat32"))
+ return &partition_basic_data_guid;
+
+ return NULL;
+}
+
+static __maybe_unused int efi_partition_mkpart(struct partition_desc *pd,
+ const char *name, const char *fs_type,
+ uint64_t start_lba, uint64_t end_lba)
+{
+ struct efi_partition_desc *epd = container_of(pd, struct efi_partition_desc, pd);
+ struct efi_partition *epart;
+ struct partition *part;
+ gpt_header *gpt = epd->gpt;
+ int num_parts = le32_to_cpu(gpt->num_partition_entries);
+ gpt_entry *pte;
+ int i;
+ const guid_t *guid;
+
+ if (start_lba < 34) {
+ pr_err("invalid start LBA %lld, minimum is 34\n", start_lba);
+ return -EINVAL;
+ }
+
+ if (end_lba >= last_lba(pd->blk) - 33) {
+ pr_err("invalid end LBA %lld, maximum is %lld\n", start_lba,
+ last_lba(pd->blk) - 33);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < num_parts; i++) {
+ if (!is_pte_valid(&epd->ptes[i], last_lba(pd->blk)))
+ break;
+ }
+
+ if (i == num_parts) {
+ pr_err("partition table is full\n");
+ return -ENOSPC;
+ }
+
+ guid = fs_type_to_guid(fs_type);
+ if (!guid) {
+ pr_err("Unknown fs type %s\n", fs_type);
+ return -EINVAL;
+ }
+
+ pte = &epd->ptes[i];
+ epart = xzalloc(sizeof(*epart));
+ part = &epart->part;
+
+ part->first_sec = start_lba;
+ part->size = end_lba - start_lba + 1;
+ part->typeuuid = *guid;
+
+ pte->partition_type_guid = *guid;
+ generate_random_guid((unsigned char *)&pte->unique_partition_guid);
+ pte->starting_lba = cpu_to_le64(start_lba);
+ pte->ending_lba = cpu_to_le64(end_lba);
+ part_get_efi_name(pte, name);
+ part_set_efi_name(pte, part->name);
+ part->num = i;
+
+ list_add_tail(&part->list, &pd->partitions);
+
+ return 0;
+}
+
+static __maybe_unused int efi_partition_rmpart(struct partition_desc *pd, struct partition *part)
+{
+ struct efi_partition *epart = container_of(part, struct efi_partition, part);
+
+ memset(epart->pte, 0, sizeof(*epart->pte));
+
+ list_del(&part->list);
+ free(epart);
+
+ return 0;
+}
+
+static int efi_protective_mbr(struct block_device *blk)
+{
+ struct partition_desc *pdesc;
+ int ret;
+
+ pdesc = partition_table_new(blk, "msdos");
+ if (IS_ERR(pdesc)) {
+ printf("Error: Cannot create partition table: %pe\n", pdesc);
+ return PTR_ERR(pdesc);
+ }
+
+ ret = partition_create(pdesc, "primary", "0xee", 1, last_lba(blk));
+ if (ret) {
+ pr_err("Cannot create partition: %pe\n", ERR_PTR(ret));
+ goto out;
+ }
+
+ ret = partition_table_write(pdesc);
+ if (ret) {
+ pr_err("Cannot write partition: %pe\n", ERR_PTR(ret));
+ goto out;
+ }
+out:
+ partition_table_free(pdesc);
+
+ return ret;
+}
+
+static __maybe_unused int efi_partition_write(struct partition_desc *pd)
+{
+ struct block_device *blk = pd->blk;
+ struct efi_partition_desc *epd = container_of(pd, struct efi_partition_desc, pd);
+ gpt_header *gpt = epd->gpt, *altgpt;
+ int ret;
+ uint32_t count;
+ uint64_t from, size;
+
+ if (le32_to_cpu(gpt->num_partition_entries) != 128) {
+ /*
+ * This is not yet properly implemented. At least writing of the
+ * alternative GPT is not correctly implemented for this case as
+ * we can't assume that the partition entries are written at
+ * last_lba() - 32, we would have to calculate that from the number
+ * of partition entries.
+ */
+ pr_err("num_partition_entries is != 128. This is not yet supported for writing\n");
+ return -EINVAL;
+ }
+
+ count = le32_to_cpu(gpt->num_partition_entries) *
+ le32_to_cpu(gpt->sizeof_partition_entry);
+
+ gpt->my_lba = cpu_to_le64(1);
+ gpt->partition_entry_array_crc32 = cpu_to_le32(efi_crc32(
+ (const unsigned char *)epd->ptes, count));
+ gpt->header_crc32 = 0;
+ gpt->header_crc32 = cpu_to_le32(efi_crc32((const unsigned char *)gpt,
+ le32_to_cpu(gpt->header_size)));
+
+ ret = efi_protective_mbr(blk);
+ if (ret)
+ return ret;
+
+ ret = block_write(blk, gpt, 1, 1);
+ if (ret)
+ goto err_block_write;
+
+ from = le64_to_cpu(gpt->partition_entry_lba);
+ size = count / GPT_BLOCK_SIZE;
+
+ ret = block_write(blk, epd->ptes, from, size);
+ if (ret)
+ goto err_block_write;
+
+ altgpt = xmemdup(gpt, SECTOR_SIZE);
+
+ altgpt->alternate_lba = cpu_to_le64(1);
+ altgpt->my_lba = cpu_to_le64(last_lba(blk));
+ altgpt->partition_entry_lba = cpu_to_le64(last_lba(blk) - 32);
+ altgpt->header_crc32 = 0;
+ altgpt->header_crc32 = cpu_to_le32(efi_crc32((const unsigned char *)altgpt,
+ le32_to_cpu(altgpt->header_size)));
+ ret = block_write(blk, altgpt, last_lba(blk), 1);
+
+ free(altgpt);
+
+ if (ret)
+ goto err_block_write;
+ ret = block_write(blk, epd->ptes, last_lba(blk) - 32, 32);
+ if (ret)
+ goto err_block_write;
+
+ return 0;
+
+err_block_write:
+ pr_err("Cannot write to block device: %pe\n", ERR_PTR(ret));
- free(pd);
+ return ret;
}
static struct partition_parser efi_partition_parser = {
.parse = efi_partition,
.partition_free = efi_partition_free,
+#ifdef CONFIG_PARTITION_MANIPULATION
+ .create = efi_partition_create_table,
+ .mkpart = efi_partition_mkpart,
+ .rmpart = efi_partition_rmpart,
+ .write = efi_partition_write,
+#endif
.type = filetype_gpt,
+ .name = "gpt",
};
static int efi_partition_init(void)
--
2.39.2
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