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>

1 files changed, 26 insertions, 18 deletions

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 @@ static const void *boot_get_kernel(cmd_tbl_t *cmdtp, int flag, int argc,
  *  - 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 @@ static int bootm_start_standalone(ulong iflag, int argc, char * const argv[])
 		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 @@ static int do_bootm_subcommand(cmd_tbl_t *cmdtp, int flag, int argc,
 	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 @@ int do_bootm(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 #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 @@ static const void *boot_get_kernel(cmd_tbl_t *cmdtp, int flag, int argc,
 #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 @@ static int do_bootm_netbsd(int flag, int argc, char * const argv[],
 	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]);