[U-Boot] [PATCH 3/6] efi_loader: bootmgr: add load option helper functions

[AKASHI Takahiro]

In this patch, helper functions for an load option variable (BootXXXX)
are added:
* efi_parse_load_option(): parse a string into load_option data
			   (renamed from parse_load_option and exported)
* efi_marshel_load_option(): convert load_option data into a string

Those functions will be used to implement efishell command.

Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
---
 include/efi_loader.h         | 25 +++++++++++++
 lib/efi_loader/efi_bootmgr.c | 68 ++++++++++++++++++++++++------------
 2 files changed, 70 insertions(+), 23 deletions(-)

diff --git a/include/efi_loader.h b/include/efi_loader.h
index b73fbb6de23f..1cabb1680d20 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -502,6 +502,31 @@ efi_status_t EFIAPI efi_set_variable(u16 *variable_name, efi_guid_t *vendor,
 				     u32 attributes, efi_uintn_t data_size,
 				     void *data);
 
+/*
+ * See section 3.1.3 in the v2.7 UEFI spec for more details on
+ * the layout of EFI_LOAD_OPTION.  In short it is:
+ *
+ *    typedef struct _EFI_LOAD_OPTION {
+ *        UINT32 Attributes;
+ *        UINT16 FilePathListLength;
+ *        // CHAR16 Description[];   <-- variable length, NULL terminated
+ *        // EFI_DEVICE_PATH_PROTOCOL FilePathList[];
+ *						 <-- FilePathListLength bytes
+ *        // UINT8 OptionalData[];
+ *    } EFI_LOAD_OPTION;
+ */
+struct load_option {
+	u32 attributes;
+	u16 file_path_length;
+	u16 *label;
+	struct efi_device_path *file_path;
+	u8 *optional_data;
+};
+
+void efi_parse_load_option(struct load_option *lo, void *ptr);
+unsigned long efi_marshal_load_option(u32 attr, u16 *label,
+				      struct efi_device_path *file_path,
+				      char *option, void **data);
 void *efi_bootmgr_load(struct efi_device_path **device_path,
 		       struct efi_device_path **file_path);
 
diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
index 0c5764db127b..c2d29f956065 100644
--- a/lib/efi_loader/efi_bootmgr.c
+++ b/lib/efi_loader/efi_bootmgr.c
@@ -30,28 +30,8 @@ static const struct efi_runtime_services *rs;
  */
 
 
-/*
- * See section 3.1.3 in the v2.7 UEFI spec for more details on
- * the layout of EFI_LOAD_OPTION.  In short it is:
- *
- *    typedef struct _EFI_LOAD_OPTION {
- *        UINT32 Attributes;
- *        UINT16 FilePathListLength;
- *        // CHAR16 Description[];   <-- variable length, NULL terminated
- *        // EFI_DEVICE_PATH_PROTOCOL FilePathList[];  <-- FilePathListLength bytes
- *        // UINT8 OptionalData[];
- *    } EFI_LOAD_OPTION;
- */
-struct load_option {
-	u32 attributes;
-	u16 file_path_length;
-	u16 *label;
-	struct efi_device_path *file_path;
-	u8 *optional_data;
-};
-
 /* parse an EFI_LOAD_OPTION, as described above */
-static void parse_load_option(struct load_option *lo, void *ptr)
+void efi_parse_load_option(struct load_option *lo, void *ptr)
 {
 	lo->attributes = *(u32 *)ptr;
 	ptr += sizeof(u32);
@@ -60,7 +40,7 @@ static void parse_load_option(struct load_option *lo, void *ptr)
 	ptr += sizeof(u16);
 
 	lo->label = ptr;
-	ptr += (u16_strlen(lo->label) + 1) * 2;
+	ptr += (u16_strlen(lo->label) + 1) * sizeof(u16);
 
 	lo->file_path = ptr;
 	ptr += lo->file_path_length;
@@ -68,6 +48,48 @@ static void parse_load_option(struct load_option *lo, void *ptr)
 	lo->optional_data = ptr;
 }
 
+unsigned long efi_marshal_load_option(u32 attr, u16 *label,
+				      struct efi_device_path *file_path,
+				      char *option, void **data)
+{
+	unsigned long size;
+	unsigned long label_len, option_len;
+	u16 file_path_len;
+	void *p;
+
+	label_len = (u16_strlen(label) + 1) * sizeof(u16);
+	file_path_len = efi_dp_size(file_path)
+			+ sizeof(struct efi_device_path); /* for END */
+	option_len = strlen(option);
+
+	/* total size */
+	size = sizeof(attr);
+	size += file_path_len;
+	size += label_len;
+	size += option_len + 1;
+	p = malloc(size);
+	if (!p)
+		return 0;
+
+	/* copy data */
+	*data = p;
+	memcpy(p, &attr, sizeof(attr));
+	p += sizeof(attr);
+	memcpy(p, &file_path_len, sizeof(file_path_len));
+	p += sizeof(file_path_len);
+	memcpy(p, label, label_len);
+	p += label_len;
+
+	memcpy(p, file_path, file_path_len);
+	p += file_path_len;
+
+	memcpy(p, option, option_len);
+	p += option_len;
+	*(char *)p = '\0';
+
+	return size;
+}
+
 /* free() the result */
 static void *get_var(u16 *name, const efi_guid_t *vendor,
 		     efi_uintn_t *size)
@@ -115,7 +137,7 @@ static void *try_load_entry(uint16_t n, struct efi_device_path **device_path,
 	if (!load_option)
 		return NULL;
 
-	parse_load_option(&lo, load_option);
+	efi_parse_load_option(&lo, load_option);
 
 	if (lo.attributes & LOAD_OPTION_ACTIVE) {
 		efi_status_t ret;
-- 
2.19.0