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authorHeinrich Schuchardt <xypron.glpk@gmx.de>2018-01-19 20:24:49 +0100
committerAlexander Graf <agraf@suse.de>2018-01-22 23:09:14 +0100
commit65436f91c5ba76f176a1f1d20801837c9746bb82 (patch)
treed5b114d2154ae83ac332409a2362fc9cd2b62d53
parent4f94865b30e07a8c140751b0c0b238960fa27b8c (diff)
downloadu-boot-65436f91c5ba76f176a1f1d20801837c9746bb82.tar.gz
efi_loader: provide function to get last node of a device path
On a block device and its partitions the same protocols can be installed. To tell the apart we can use the type of the last node of the device path which is not the end node. The patch provides a utility function to find this last node. Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de> Signed-off-by: Alexander Graf <agraf@suse.de>
-rw-r--r--include/efi_loader.h3
-rw-r--r--lib/efi_loader/efi_device_path.c20
2 files changed, 23 insertions, 0 deletions
diff --git a/include/efi_loader.h b/include/efi_loader.h
index ff59005ff4..2db4e9c09b 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -312,6 +312,9 @@ struct efi_device_path *efi_dp_from_eth(void);
struct efi_device_path *efi_dp_from_mem(uint32_t mem_type,
uint64_t start_address,
uint64_t end_address);
+/* Determine the last device path node that is not the end node. */
+const struct efi_device_path *efi_dp_last_node(
+ const struct efi_device_path *dp);
efi_status_t efi_dp_split_file_path(struct efi_device_path *full_path,
struct efi_device_path **device_path,
struct efi_device_path **file_path);
diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
index f00a0ce645..c941ea7717 100644
--- a/lib/efi_loader/efi_device_path.c
+++ b/lib/efi_loader/efi_device_path.c
@@ -208,6 +208,26 @@ struct efi_object *efi_dp_find_obj(struct efi_device_path *dp,
return efiobj;
}
+/*
+ * Determine the last device path node that is not the end node.
+ *
+ * @dp device path
+ * @return last node before the end node if it exists
+ * otherwise NULL
+ */
+const struct efi_device_path *efi_dp_last_node(const struct efi_device_path *dp)
+{
+ struct efi_device_path *ret;
+
+ if (!dp || dp->type == DEVICE_PATH_TYPE_END)
+ return NULL;
+ while (dp) {
+ ret = (struct efi_device_path *)dp;
+ dp = efi_dp_next(dp);
+ }
+ return ret;
+}
+
/* return size not including End node: */
unsigned efi_dp_size(const struct efi_device_path *dp)
{