[PATCH v2 1/2] part: Add a function to find ESP partition

Mayuresh Chitale
2024-01-16T12:37:09Z

If a disk has an EFI system partition (ESP) then it can be used to
locate the boot files. Add a function to find the ESP.

Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
---
disk/part.c | 16 ++++++++++++++++
include/part.h | 11 +++++++++++
2 files changed, 27 insertions(+)

diff --git a/disk/part.c b/disk/part.c
index 36b88205eca..6b1fbc18637 100644
--- a/disk/part.c
+++ b/disk/part.c
@@ -848,3 +848,19 @@ int part_get_bootable(struct blk_desc *desc)

return 0;
}
+
+int part_get_esp(struct blk_desc *desc)
+{
+ struct disk_partition info;
+ int p;
+
+ for (p = 1; p <= MAX_SEARCH_PARTITIONS; p++) {
+ int ret;
+
+ ret = part_get_info(desc, p, &info);
+ if (!ret && (info.bootable & PART_EFI_SYSTEM_PARTITION))
+ return p;
+ }
+
+ return 0;
+}
diff --git a/include/part.h b/include/part.h
index db34bc6bb7d..30e049c8f19 100644
--- a/include/part.h
+++ b/include/part.h
@@ -690,6 +690,14 @@ int part_get_type_by_name(const char *name);
*/
int part_get_bootable(struct blk_desc *desc);

+/**
+ * part_get_esp() - Find the EFI system partition
+ *
+ * @desc: Block-device descriptor
+ * @Return the EFI system partition, or 0 if there is none
+ */
+int part_get_esp(struct blk_desc *desc);
+
#else
static inline int part_driver_get_count(void)
{ return 0; }
@@ -700,6 +708,9 @@ static inline struct part_driver *part_driver_get_first(void)
static inline bool part_get_bootable(struct blk_desc *desc)
{ return false; }

+static inline bool part_get_esp(struct blk_desc *desc)
+{ return false; }
+
#endif /* CONFIG_PARTITIONS */

#endif /* _PART_H */
--
2.34.1