x86: zboot: Set up a sub-command structure

Add subcommands to zboot. At present there is only one called 'start'
which does the whole boot. It is the default command so is optional.

Change the 's' string variable to const while we are here.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
[bmeng: reduce maxargs to 6 of 'zboot start' subcommand]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/lib/zimage.c

@@ -63,6 +63,12 @@ struct zboot_state {
 	ulong load_address;
 } state;
 
+enum {
+	ZBOOT_STATE_START	= BIT(0),
+
+	ZBOOT_STATE_COUNT	= 1,
+};
+
 static void build_command_line(char *command_line, int auto_boot)
 {
 	char *env_command_line;
@@ -328,10 +334,11 @@ int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot,
 	return 0;
 }
 
-int do_zboot(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
+static int do_zboot_start(struct cmd_tbl *cmdtp, int flag, int argc,
+			  char *const argv[])
 {
 	struct boot_params *base_ptr;
-	char *s;
+	const char *s;
 
 	memset(&state, '\0', sizeof(state));
 	if (argc >= 2) {
@@ -373,9 +380,54 @@ int do_zboot(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 	return boot_linux_kernel((ulong)base_ptr, state.load_address, false);
 }
 
-U_BOOT_CMD(
+/* Note: This defines the complete_zboot() function */
-	zboot, 5, 0,	do_zboot,
+U_BOOT_SUBCMDS(zboot,
-	"Boot bzImage",
+	U_BOOT_CMD_MKENT(start, 6, 1, do_zboot_start, "", ""),
+)
+
+int do_zboot_states(struct cmd_tbl *cmdtp, int flag, int argc,
+		    char *const argv[], int state_mask)
+{
+	int i;
+
+	for (i = 0; i < ZBOOT_STATE_COUNT; i++) {
+		struct cmd_tbl *cmd = &zboot_subcmds[i];
+		int mask = 1 << i;
+		int ret;
+
+		if (mask & state_mask) {
+			ret = cmd->cmd(cmd, flag, argc, argv);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+int do_zboot_parent(struct cmd_tbl *cmdtp, int flag, int argc,
+		    char *const argv[], int *repeatable)
+{
+	/* determine if we have a sub command */
+	if (argc > 1) {
+		char *endp;
+
+		simple_strtoul(argv[1], &endp, 16);
+		/*
+		 * endp pointing to nul means that argv[1] was just a valid
+		 * number, so pass it along to the normal processing
+		 */
+		if (*endp)
+			return do_zboot(cmdtp, flag, argc, argv, repeatable);
+	}
+
+	do_zboot_states(cmdtp, flag, argc, argv, ZBOOT_STATE_START);
+
+	return CMD_RET_FAILURE;
+}
+
+U_BOOT_CMDREP_COMPLETE(
+	zboot, 6, do_zboot_parent, "Boot bzImage",
 	"[addr] [size] [initrd addr] [initrd size]\n"
 	"      addr -        The optional starting address of the bzimage.\n"
 	"                    If not set it defaults to the environment\n"
@@ -384,4 +436,8 @@ U_BOOT_CMD(
 	"                    zero.\n"
 	"      initrd addr - The address of the initrd image to use, if any.\n"
 	"      initrd size - The size of the initrd image to use, if any.\n"
+	"\n"
+	"Sub-commands to do part of the zboot sequence:\n"
+	"\tstart [addr [arg ...]] - specify arguments\n",
+	complete_zboot
 );