Clarify bootm OS arguments

At present the arguments to bootm are processed in a somewhat confusing
way. Sub-functions must know how many arguments their calling functions
have processed, and the OS boot function must also have this information.
Also it isn't obvious that 'bootm' and 'bootm start' provide arguments in
the same way.

Adjust the code so that arguments are removed from the list before calling
a sub-function. This means that all functions can know that argv[0] is the
first argument of which they need to take notice.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/microblaze/lib/bootm.c b/arch/microblaze/lib/bootm.c
index 3842709..b328f94 100644
--- a/arch/microblaze/lib/bootm.c
+++ b/arch/microblaze/lib/bootm.c
@@ -62,8 +62,8 @@
 
 	bootstage_mark(BOOTSTAGE_ID_RUN_OS);
 
-	if (!of_flat_tree && argc > 3)
-		of_flat_tree = (char *)simple_strtoul(argv[3], NULL, 16);
+	if (!of_flat_tree && argc > 1)
+		of_flat_tree = (char *)simple_strtoul(argv[1], NULL, 16);
 
 	/* fixup the initrd now that we know where it should be */
 	if (images->rd_start && images->rd_end && of_flat_tree)
diff --git a/arch/nios2/lib/bootm.c b/arch/nios2/lib/bootm.c
index f32be52..114e146 100644
--- a/arch/nios2/lib/bootm.c
+++ b/arch/nios2/lib/bootm.c
@@ -40,8 +40,8 @@
 	if (images->ft_len)
 		of_flat_tree = images->ft_addr;
 #endif
-	if (!of_flat_tree && argc > 3)
-		of_flat_tree = (char *)simple_strtoul(argv[3], NULL, 16);
+	if (!of_flat_tree && argc > 1)
+		of_flat_tree = (char *)simple_strtoul(argv[1], NULL, 16);
 	if (of_flat_tree)
 		initrd_end = (ulong)of_flat_tree;
 
diff --git a/arch/openrisc/lib/bootm.c b/arch/openrisc/lib/bootm.c
index 2c5d9ae..7f716b8 100644
--- a/arch/openrisc/lib/bootm.c
+++ b/arch/openrisc/lib/bootm.c
@@ -63,8 +63,8 @@
 
 	show_boot_progress(15);
 
-	if (!of_flat_tree && argc > 3)
-		of_flat_tree = (char *)simple_strtoul(argv[3], NULL, 16);
+	if (!of_flat_tree && argc > 1)
+		of_flat_tree = (char *)simple_strtoul(argv[1], NULL, 16);
 #ifdef DEBUG
 	printf("## Transferring control to Linux (at address 0x%08lx) " \
 				"ramdisk 0x%08lx, FDT 0x%08lx...\n",
diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c
index e452fca..6a6241d 100644
--- a/common/cmd_bootm.c
+++ b/common/cmd_bootm.c
@@ -104,9 +104,18 @@
  *  - verified image architecture (PPC) and type (KERNEL or MULTI),
  *  - loaded (first part of) image to header load address,
  *  - disabled interrupts.
+ *
+ * @flag: Command flags (CMD_FLAG_...)
+ * @argc: Number of arguments. Note that the arguments are shifted down
+ *	 so that 0 is the first argument not processed by U-Boot, and
+ *	 argc is adjusted accordingly. This avoids confusion as to how
+ *	 many arguments are available for the OS.
+ * @images: Pointers to os/initrd/fdt
+ * @return 1 on error. On success the OS boots so this function does
+ * not return.
  */
 typedef int boot_os_fn(int flag, int argc, char * const argv[],
-			bootm_headers_t *images); /* pointers to os/initrd/fdt */
+			bootm_headers_t *images);
 
 #ifdef CONFIG_BOOTM_LINUX
 extern boot_os_fn do_bootm_linux;
@@ -457,7 +466,7 @@
 		return 0;
 	}
 	appl = (int (*)(int, char * const []))(ulong)ntohl(images.ep);
-	(*appl)(argc-1, &argv[1]);
+	(*appl)(argc, argv);
 	return 0;
 }
 
@@ -486,17 +495,15 @@
 	cmd_tbl_t *c;
 	boot_os_fn *boot_fn;
 
-	c = find_cmd_tbl(argv[1], &cmd_bootm_sub[0], ARRAY_SIZE(cmd_bootm_sub));
+	c = find_cmd_tbl(argv[0], &cmd_bootm_sub[0], ARRAY_SIZE(cmd_bootm_sub));
+	argc--; argv++;
 
 	if (c) {
 		state = (long)c->cmd;
 
 		/* treat start special since it resets the state machine */
-		if (state == BOOTM_STATE_START) {
-			argc--;
-			argv++;
+		if (state == BOOTM_STATE_START)
 			return bootm_start(cmdtp, flag, argc, argv);
-		}
 	} else {
 		/* Unrecognized command */
 		return CMD_RET_USAGE;
@@ -611,11 +618,12 @@
 #endif
 
 	/* determine if we have a sub command */
-	if (argc > 1) {
+	argc--; argv++;
+	if (argc > 0) {
 		char *endp;
 
-		simple_strtoul(argv[1], &endp, 16);
-		/* endp pointing to NULL means that argv[1] was just a
+		simple_strtoul(argv[0], &endp, 16);
+		/* endp pointing to NULL means that argv[0] was just a
 		 * valid number, pass it along to the normal bootm processing
 		 *
 		 * If endp is ':' or '#' assume a FIT identifier so pass
@@ -816,22 +824,22 @@
 #endif
 
 	/* find out kernel image address */
-	if (argc < 2) {
+	if (argc < 1) {
 		img_addr = load_addr;
 		debug("*  kernel: default image load address = 0x%08lx\n",
 				load_addr);
 #if defined(CONFIG_FIT)
-	} else if (fit_parse_conf(argv[1], load_addr, &img_addr,
+	} else if (fit_parse_conf(argv[0], load_addr, &img_addr,
 							&fit_uname_config)) {
 		debug("*  kernel: config '%s' from image at 0x%08lx\n",
 				fit_uname_config, img_addr);
-	} else if (fit_parse_subimage(argv[1], load_addr, &img_addr,
+	} else if (fit_parse_subimage(argv[0], load_addr, &img_addr,
 							&fit_uname_kernel)) {
 		debug("*  kernel: subimage '%s' from image at 0x%08lx\n",
 				fit_uname_kernel, img_addr);
 #endif
 	} else {
-		img_addr = simple_strtoul(argv[1], NULL, 16);
+		img_addr = simple_strtoul(argv[0], NULL, 16);
 		debug("*  kernel: cmdline image address = 0x%08lx\n", img_addr);
 	}
 
@@ -1401,16 +1409,16 @@
 	consdev = "scc3";
 #endif
 
-	if (argc > 2) {
+	if (argc > 0) {
 		ulong len;
 		int   i;
 
-		for (i = 2, len = 0; i < argc; i += 1)
+		for (i = 0, len = 0; i < argc; i += 1)
 			len += strlen(argv[i]) + 1;
 		cmdline = malloc(len);
 
-		for (i = 2, len = 0; i < argc; i += 1) {
-			if (i > 2)
+		for (i = 0, len = 0; i < argc; i += 1) {
+			if (i > 0)
 				cmdline[len++] = ' ';
 			strcpy(&cmdline[len], argv[i]);
 			len += strlen(argv[i]);
diff --git a/common/image-fdt.c b/common/image-fdt.c
index 0d421d9..d99f444 100644
--- a/common/image-fdt.c
+++ b/common/image-fdt.c
@@ -248,13 +248,16 @@
 	ulong		default_addr;
 	int		fdt_noffset;
 #endif
+	const char *select = NULL;
 
 	*of_flat_tree = NULL;
 	*of_size = 0;
 
-	if (argc > 3 || genimg_has_config(images)) {
+	if (argc > 2)
+		select = argv[2];
+	if (select || genimg_has_config(images)) {
 #if defined(CONFIG_FIT)
-		if (argc > 3) {
+		if (select) {
 			/*
 			 * If the FDT blob comes from the FIT image and the
 			 * FIT image address is omitted in the command line
@@ -268,18 +271,18 @@
 			else
 				default_addr = load_addr;
 
-			if (fit_parse_conf(argv[3], default_addr,
+			if (fit_parse_conf(select, default_addr,
 					   &fdt_addr, &fit_uname_config)) {
 				debug("*  fdt: config '%s' from image at 0x%08lx\n",
 				      fit_uname_config, fdt_addr);
-			} else if (fit_parse_subimage(argv[3], default_addr,
+			} else if (fit_parse_subimage(select, default_addr,
 				   &fdt_addr, &fit_uname_fdt)) {
 				debug("*  fdt: subimage '%s' from image at 0x%08lx\n",
 				      fit_uname_fdt, fdt_addr);
 			} else
 #endif
 			{
-				fdt_addr = simple_strtoul(argv[3], NULL, 16);
+				fdt_addr = simple_strtoul(select, NULL, 16);
 				debug("*  fdt: cmdline image address = 0x%08lx\n",
 				      fdt_addr);
 			}
diff --git a/common/image.c b/common/image.c
index f863502..1be384f 100644
--- a/common/image.c
+++ b/common/image.c
@@ -816,20 +816,23 @@
 	ulong		default_addr;
 	int		rd_noffset;
 #endif
+	const char *select = NULL;
 
 	*rd_start = 0;
 	*rd_end = 0;
 
+	if (argc >= 2)
+		select = argv[1];
 	/*
 	 * Look for a '-' which indicates to ignore the
 	 * ramdisk argument
 	 */
-	if ((argc >= 3) && (strcmp(argv[2], "-") ==  0)) {
+	if (select && strcmp(select, "-") ==  0) {
 		debug("## Skipping init Ramdisk\n");
 		rd_len = rd_data = 0;
-	} else if (argc >= 3 || genimg_has_config(images)) {
+	} else if (select || genimg_has_config(images)) {
 #if defined(CONFIG_FIT)
-		if (argc >= 3) {
+		if (select) {
 			/*
 			 * If the init ramdisk comes from the FIT image and
 			 * the FIT image address is omitted in the command
@@ -841,12 +844,12 @@
 			else
 				default_addr = load_addr;
 
-			if (fit_parse_conf(argv[2], default_addr,
-						&rd_addr, &fit_uname_config)) {
+			if (fit_parse_conf(select, default_addr,
+					   &rd_addr, &fit_uname_config)) {
 				debug("*  ramdisk: config '%s' from image at "
 						"0x%08lx\n",
 						fit_uname_config, rd_addr);
-			} else if (fit_parse_subimage(argv[2], default_addr,
+			} else if (fit_parse_subimage(select, default_addr,
 						&rd_addr, &fit_uname_ramdisk)) {
 				debug("*  ramdisk: subimage '%s' from image at "
 						"0x%08lx\n",
@@ -854,7 +857,7 @@
 			} else
 #endif
 			{
-				rd_addr = simple_strtoul(argv[2], NULL, 16);
+				rd_addr = simple_strtoul(select, NULL, 16);
 				debug("*  ramdisk: cmdline image address = "
 						"0x%08lx\n",
 						rd_addr);
@@ -918,7 +921,10 @@
 #endif
 		default:
 #ifdef CONFIG_SUPPORT_RAW_INITRD
-			if (argc >= 3 && (end = strchr(argv[2], ':'))) {
+			end = NULL;
+			if (select)
+				end = strchr(select, ':');
+			if (end) {
 				rd_len = simple_strtoul(++end, NULL, 16);
 				rd_data = rd_addr;
 			} else