[PATCH v2 1/4] partitions: efi: add support to specify gpt-location

[Marco Felsch <m.felsch@pengutronix.de>]

The actual GPT partition entries array can be placed everywhere, only
the GPT header needs to be placed at LBA1. Add support for this feature
to allow platform like i.MX3/5/6 to create a GPT partition table without
overriding the actual barebox image.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
v2:
- new

 commands/parted.c       |  3 ++-
 common/partitions.c     |  5 +++--
 common/partitions/dos.c |  3 ++-
 common/partitions/efi.c | 15 +++++++++++----
 include/partitions.h    |  5 +++--
 5 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/commands/parted.c b/commands/parted.c
index 68b056a0758a..90cee1ede10e 100644
--- a/commands/parted.c
+++ b/commands/parted.c
@@ -217,13 +217,14 @@ static int do_rmpart(struct block_device *blk, int argc, char *argv[])
 static int do_mklabel(struct block_device *blk, int argc, char *argv[])
 {
 	struct partition_desc *pdesc;
+	uint64_t gpt_location = 2;
 
 	if (argc < 2) {
 		printf("Error: Expecting a disk label type.\n");
 		return -EINVAL;
 	}
 
-	pdesc = partition_table_new(blk, argv[1]);
+	pdesc = partition_table_new(blk, argv[1], gpt_location);
 	if (IS_ERR(pdesc)) {
 		printf("Error: Cannot create partition table: %pe\n", pdesc);
 		return PTR_ERR(pdesc);
diff --git a/common/partitions.c b/common/partitions.c
index bc90f51f6112..ec50368c3e98 100644
--- a/common/partitions.c
+++ b/common/partitions.c
@@ -101,7 +101,8 @@ static struct partition_parser *partition_parser_get_by_filetype(uint8_t *buf)
 	return NULL;
 }
 
-struct partition_desc *partition_table_new(struct block_device *blk, const char *type)
+struct partition_desc *
+partition_table_new(struct block_device *blk, const char *type, sector_t gpt_location)
 {
 	struct partition_desc *pdesc;
 	struct partition_parser *parser;
@@ -116,7 +117,7 @@ struct partition_desc *partition_table_new(struct block_device *blk, const char
 	return ERR_PTR(-ENOSYS);
 
 found:
-	pdesc = parser->create(blk);
+	pdesc = parser->create(blk, gpt_location);
 	if (IS_ERR(pdesc))
 		return ERR_CAST(pdesc);
 
diff --git a/common/partitions/dos.c b/common/partitions/dos.c
index 6204fdabc81f..fcd43bf6aaa8 100644
--- a/common/partitions/dos.c
+++ b/common/partitions/dos.c
@@ -316,7 +316,8 @@ static void dos_partition_free(struct partition_desc *pd)
 	free(pd);
 }
 
-static __maybe_unused struct partition_desc *dos_partition_create_table(struct block_device *blk)
+static __maybe_unused struct partition_desc *
+dos_partition_create_table(struct block_device *blk, sector_t gpt_location)
 {
 	struct dos_partition_desc *dpd = xzalloc(512);
 
diff --git a/common/partitions/efi.c b/common/partitions/efi.c
index 840d6a83b795..8f9f9665c75b 100644
--- a/common/partitions/efi.c
+++ b/common/partitions/efi.c
@@ -579,11 +579,18 @@ static void efi_partition_free(struct partition_desc *pd)
 	free(epd);
 }
 
-static __maybe_unused struct partition_desc *efi_partition_create_table(struct block_device *blk)
+static __maybe_unused struct partition_desc *
+efi_partition_create_table(struct block_device *blk, sector_t gpt_location)
 {
 	struct efi_partition_desc *epd = xzalloc(sizeof(*epd));
 	gpt_header *gpt;
 
+	if (gpt_location < 2) {
+		pr_err("Invalid starting LBA (%llu) of array of partition entries\n",
+		       gpt_location);
+		return ERR_PTR(-EINVAL);
+	}
+
 	partition_desc_init(&epd->pd, blk);
 
 	epd->gpt = xzalloc(512);
@@ -594,10 +601,10 @@ static __maybe_unused struct partition_desc *efi_partition_create_table(struct b
 	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->first_usable_lba = cpu_to_le64(gpt_location + 32);
 	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->partition_entry_lba = cpu_to_le64(gpt_location);
 	gpt->num_partition_entries = cpu_to_le32(128);
 	gpt->sizeof_partition_entry = cpu_to_le32(sizeof(gpt_entry));
 
@@ -710,7 +717,7 @@ static int efi_protective_mbr(struct block_device *blk)
 	struct partition_desc *pdesc;
 	int ret;
 
-	pdesc = partition_table_new(blk, "msdos");
+	pdesc = partition_table_new(blk, "msdos", 0);
 	if (IS_ERR(pdesc)) {
 		printf("Error: Cannot create partition table: %pe\n", pdesc);
 		return PTR_ERR(pdesc);
diff --git a/include/partitions.h b/include/partitions.h
index 785fb77ab167..f893f94b259f 100644
--- a/include/partitions.h
+++ b/include/partitions.h
@@ -41,7 +41,7 @@ struct partition_desc {
 struct partition_parser {
 	struct partition_desc *(*parse)(void *buf, struct block_device *blk);
 	void (*partition_free)(struct partition_desc *pd);
-	struct partition_desc *(*create)(struct block_device *blk);
+	struct partition_desc *(*create)(struct block_device *blk, sector_t gpt_location);
 	int (*mkpart)(struct partition_desc *pd, const char *name, const char *fs_type,
 		      uint64_t start, uint64_t end);
 	int (*rmpart)(struct partition_desc *pd, struct partition *part);
@@ -58,7 +58,8 @@ struct partition_parser {
 void partition_desc_init(struct partition_desc *pd, struct block_device *blk);
 int partition_parser_register(struct partition_parser *p);
 struct partition_desc *partition_table_read(struct block_device *blk);
-struct partition_desc *partition_table_new(struct block_device *blk, const char *type);
+struct partition_desc *
+partition_table_new(struct block_device *blk, const char *type, sector_t gpt_location);
 int partition_table_write(struct partition_desc *pdesc);
 int partition_create(struct partition_desc *pdesc, const char *name,
 		     const char *fs_type, uint64_t lba_start, uint64_t lba_end);
-- 
2.39.5