[PATCH v3 2/2] efi_loader: identify EFI system partition

[Heinrich Schuchardt]

In subsequent patches UEFI variables shalled be stored on the EFI system
partition. Hence we need to identify the EFI system partition.

Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
v3:
	adjust commit message
v2:
	no change
---
 include/efi_loader.h      |  7 +++++++
 lib/efi_loader/efi_disk.c | 20 ++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/include/efi_loader.h b/include/efi_loader.h
index 0ba9a1f702..b7bccf50b3 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -47,6 +47,13 @@ static inline void *guidcpy(void *dst, const void *src)
 /* Root node */
 extern efi_handle_t efi_root;

+/* EFI system partition */
+extern struct efi_system_partition {
+	enum if_type if_type;
+	int devnum;
+	u8 part;
+} efi_system_partition;
+
 int __efi_entry_check(void);
 int __efi_exit_check(void);
 const char *__efi_nesting(void);
diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
index fd8fe17567..fd3df80b0b 100644
--- a/lib/efi_loader/efi_disk.c
+++ b/lib/efi_loader/efi_disk.c
@@ -13,6 +13,8 @@
 #include <part.h>
 #include <malloc.h>

+struct efi_system_partition efi_system_partition;
+
 const efi_guid_t efi_block_io_guid = EFI_BLOCK_IO_PROTOCOL_GUID;

 /**
@@ -418,6 +420,24 @@ static efi_status_t efi_disk_add_dev(
 	diskobj->ops.media = &diskobj->media;
 	if (disk)
 		*disk = diskobj;
+
+	/* Store first EFI system partition */
+	if (part && !efi_system_partition.if_type) {
+		int r;
+		disk_partition_t info;
+
+		r = part_get_info(desc, part, &info);
+		if (r)
+			return EFI_DEVICE_ERROR;
+		if (info.bootable & PART_EFI_SYSTEM_PARTITION) {
+			efi_system_partition.if_type = desc->if_type;
+			efi_system_partition.devnum = desc->devnum;
+			efi_system_partition.part = part;
+			EFI_PRINT("EFI system partition: %s %d:%d\n",
+				  blk_get_if_type_name(desc->if_type),
+				  desc->devnum, part);
+		}
+	}
 	return EFI_SUCCESS;
 }

--
2.26.1