[RFC PATCH v3 1/2] efi_loader: introduce "bootefi bootindex" command

[Masahisa Kojima]

This commit introduces the new command "bootefi bootindex".
With this command, user can select which "Boot####" option
to load and execute.

Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
---
Changes in v3:
- newly created

 cmd/bootefi.c                | 42 ++++++++++++++++++++++++++++++++++++
 include/efi_loader.h         |  1 +
 lib/efi_loader/efi_bootmgr.c |  7 +++---
 3 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index 46eebd5ee2..df86438fec 100644
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -416,6 +416,30 @@ static int do_efibootmgr(void)
 	return CMD_RET_SUCCESS;
 }
 
+/**
+ * do_efibootindex() - load and execute the specified Boot#### option
+ *
+ * Return:	status code
+ */
+static int do_efibootindex(u16 boot_index)
+{
+	efi_handle_t handle;
+	efi_status_t ret;
+	void *load_options;
+
+	ret = efi_try_load_entry(boot_index, &handle, &load_options);
+	if (ret != EFI_SUCCESS) {
+		log_notice("EFI boot manager: failed to load Boot%04X\n", boot_index);
+		return CMD_RET_FAILURE;
+	}
+
+	ret = do_bootefi_exec(handle, load_options);
+
+	if (ret != EFI_SUCCESS)
+		return CMD_RET_FAILURE;
+
+	return CMD_RET_SUCCESS;
+}
 /**
  * do_bootefi_image() - execute EFI binary
  *
@@ -654,6 +678,22 @@ static int do_bootefi(struct cmd_tbl *cmdtp, int flag, int argc,
 		return CMD_RET_FAILURE;
 	}
 
+	if (IS_ENABLED(CONFIG_CMD_BOOTEFI_BOOTMGR)) {
+		if (!strcmp(argv[1], "bootindex")) {
+			char *endp;
+			int boot_index;
+
+			if (argc < 3)
+				return CMD_RET_USAGE;
+
+			boot_index = (int)hextoul(argv[2], &endp);
+			if (*endp != '\0' || boot_index > 0xffff)
+				return CMD_RET_USAGE;
+
+			return do_efibootindex((u16)boot_index);
+		}
+	}
+
 	if (argc > 2) {
 		uintptr_t fdt_addr;
 
@@ -702,6 +742,8 @@ static char bootefi_help_text[] =
 	"\n"
 	"    If specified, the device tree located at <fdt address> gets\n"
 	"    exposed as EFI configuration table.\n"
+	"bootefi bootindex <boot option>\n"
+	"  - load and boot EFI payload based on the specified BootXXXX variable.\n"
 #endif
 	;
 #endif
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 80a5f1ec01..e5972f5fee 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -861,6 +861,7 @@ efi_status_t efi_set_load_options(efi_handle_t handle,
 				  efi_uintn_t load_options_size,
 				  void *load_options);
 efi_status_t efi_bootmgr_load(efi_handle_t *handle, void **load_options);
+efi_status_t efi_try_load_entry(u16 n, efi_handle_t *handle, void **load_options);
 
 /**
  * struct efi_image_regions - A list of memory regions
diff --git a/lib/efi_loader/efi_bootmgr.c b/lib/efi_loader/efi_bootmgr.c
index 8c04ecbdc8..a3060b5c62 100644
--- a/lib/efi_loader/efi_bootmgr.c
+++ b/lib/efi_loader/efi_bootmgr.c
@@ -42,8 +42,7 @@ static const struct efi_runtime_services *rs;
  * @load_options:	load options set on the loaded image protocol
  * Return:		status code
  */
-static efi_status_t try_load_entry(u16 n, efi_handle_t *handle,
-				   void **load_options)
+efi_status_t efi_try_load_entry(u16 n, efi_handle_t *handle, void **load_options)
 {
 	struct efi_load_option lo;
 	u16 varname[] = u"Boot0000";
@@ -165,7 +164,7 @@ efi_status_t efi_bootmgr_load(efi_handle_t *handle, void **load_options)
 		/* load BootNext */
 		if (ret == EFI_SUCCESS) {
 			if (size == sizeof(u16)) {
-				ret = try_load_entry(bootnext, handle,
+				ret = efi_try_load_entry(bootnext, handle,
 						     load_options);
 				if (ret == EFI_SUCCESS)
 					return ret;
@@ -189,7 +188,7 @@ efi_status_t efi_bootmgr_load(efi_handle_t *handle, void **load_options)
 	for (i = 0; i < num; i++) {
 		log_debug("%s trying to load Boot%04X\n", __func__,
 			  bootorder[i]);
-		ret = try_load_entry(bootorder[i], handle, load_options);
+		ret = efi_try_load_entry(bootorder[i], handle, load_options);
 		if (ret == EFI_SUCCESS)
 			break;
 	}
-- 
2.17.1