[RFC 3/3] cmd: efidebug: handle booting from removable media

[AKASHI Takahiro <takahiro.akashi@linaro.org>]

Support for booting from removable media is now added to UEFI boot
manager. Here we should modify efidebug command in order to define
a proper "BootXXXX" variable.

With this patch applied, you will be able to specify the boot order,
usb and scsi:
=> efidebug -b 1 SCSI scsi 0:1
=> efidebug boot dump
Boot0001:
attributes: A-- (0x00000001)
  label: SCSI
  file_path: /VenHw(e61d73b9-a384-4acc-aeab-82e828f3628b)/Scsi(0,0)/
	HD(1,GPT,0ed48d12-1b4c-4e08-b3ee-decf20428036,0x800,0xa000)
  data:
    00000000: 00 00
=> efideubg -b 2 USB usb 0:1
=> efidebug boot order 2 1
=> bootefi bootmgr

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
---
 cmd/efidebug.c | 46 ++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 40 insertions(+), 6 deletions(-)

diff --git a/cmd/efidebug.c b/cmd/efidebug.c
index a977ca9c72f5..aaf269cdf47d 100644
--- a/cmd/efidebug.c
+++ b/cmd/efidebug.c
@@ -933,6 +933,29 @@ out:
 	return initrd_dp;
 }
 
+/**
+ * count_arguments - count the number of arguments
+ * @argc:	Total number of arguments
+ * @argv:	Argument array
+ * Return:	Number of arguments
+ *
+ * Count the number of arguments for a given option, "-?"
+ * Specifically if the first argument is not "-?", return 0;
+ */
+static int count_arguments(int argc, char *const argv[])
+{
+	int i;
+
+	if (argv[0][0] != '-')
+		return 0;
+
+	for (i = 1; i < argc; i++)
+		if (argv[i][0] == '-')
+			break;
+
+	return i;
+}
+
 /**
  * do_efi_boot_add() - set UEFI load option
  *
@@ -945,7 +968,7 @@ out:
  *
  * Implement efidebug "boot add" sub-command. Create or change UEFI load option.
  *
- * efidebug boot add -b <id> <label> <interface> <devnum>[:<part>] <file>
+ * efidebug boot add -b <id> <label> <interface> <devnum>[:<part>] [<file>]
  *                   -i <file> <interface2> <devnum2>[:<part>] <initrd>
  *                   -s '<options>'
  */
@@ -979,7 +1002,10 @@ static int do_efi_boot_add(struct cmd_tbl *cmdtp, int flag,
 	argv++; /* 'add' */
 	for (; argc > 0; argc--, argv++) {
 		if (!strcmp(argv[0], "-b")) {
-			if (argc <  5 || lo.label) {
+			int num_args;
+
+			num_args = count_arguments(argc, argv);
+			if (num_args <  5 || num_args > 6 || lo.label) {
 				r = CMD_RET_USAGE;
 				goto out;
 			}
@@ -1000,7 +1026,8 @@ static int do_efi_boot_add(struct cmd_tbl *cmdtp, int flag,
 			utf8_utf16_strncpy(&label, argv[2], label_len);
 
 			/* file path */
-			ret = efi_dp_from_name(argv[3], argv[4], argv[5],
+			ret = efi_dp_from_name(argv[3], argv[4],
+					       num_args == 5 ? "" : argv[5],
 					       &device_path, &file_path);
 			if (ret != EFI_SUCCESS) {
 				printf("Cannot create device path for \"%s %s\"\n",
@@ -1008,10 +1035,16 @@ static int do_efi_boot_add(struct cmd_tbl *cmdtp, int flag,
 				r = CMD_RET_FAILURE;
 				goto out;
 			}
+			/* if no file name is given, use device_path */
+			if (num_args == 5) {
+				efi_free_pool(file_path);
+				file_path = device_path;
+				device_path = NULL;
+			}
 			fp_size += efi_dp_size(file_path) +
 				sizeof(struct efi_device_path);
-			argc -= 5;
-			argv += 5;
+			argc -= num_args;
+			argv += num_args;
 		} else if (!strcmp(argv[0], "-i")) {
 			if (argc < 3 || initrd_dp) {
 				r = CMD_RET_USAGE;
@@ -1078,7 +1111,8 @@ out:
 	free(data);
 	efi_free_pool(final_fp);
 	efi_free_pool(initrd_dp);
-	efi_free_pool(device_path);
+	if (device_path)
+		efi_free_pool(device_path);
 	efi_free_pool(file_path);
 	free(lo.label);
 
-- 
2.33.0