sandbox: Sort the help options

At present options are presented in essentially random order. It is easier
to browse them if they are sorted into alphabetical order. Adjust the
help function to handle this.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sandbox/cpu/start.c b/arch/sandbox/cpu/start.c
index 5b7d548..01adaeb 100644
--- a/arch/sandbox/cpu/start.c
+++ b/arch/sandbox/cpu/start.c
@@ -9,13 +9,45 @@
 #include <os.h>
 #include <cli.h>
 #include <malloc.h>
+#include <sort.h>
 #include <asm/getopt.h>
 #include <asm/io.h>
 #include <asm/sections.h>
 #include <asm/state.h>
+#include <linux/ctype.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
+/* Compare two options so that they can be sorted into alphabetical order */
+static int h_compare_opt(const void *p1, const void *p2)
+{
+	const struct sandbox_cmdline_option *opt1 = p1;
+	const struct sandbox_cmdline_option *opt2 = p2;
+	const char *str1, *str2;
+	char flag1[2], flag2[2];
+
+	opt1 = *(struct sandbox_cmdline_option **)p1;
+	opt2 = *(struct sandbox_cmdline_option **)p2;
+	flag1[1] = '\0';
+	flag2[1] = '\0';
+
+	*flag1 = opt1->flag_short < 0x100 ? opt1->flag_short : '\0';
+	*flag2 = opt2->flag_short < 0x100 ? opt2->flag_short : '\0';
+
+	str1 = *flag1 ? flag1 : opt1->flag;
+	str2 = *flag2 ? flag2 : opt2->flag;
+
+	/*
+	 * Force lower-case flags to come before upper-case ones. We only
+	 * support upper-case for short flags.
+	 */
+	if (isalpha(*str1) && isalpha(*str2) &&
+	    tolower(*str1) == tolower(*str2))
+		return isupper(*str1) - isupper(*str2);
+
+	return strcasecmp(str1, str2);
+}
+
 int sandbox_early_getopt_check(void)
 {
 	struct sandbox_state *state = state_get_current();
@@ -23,6 +55,8 @@
 	size_t num_options = __u_boot_sandbox_option_count();
 	size_t i;
 	int max_arg_len, max_noarg_len;
+	struct sandbox_cmdline_option **sorted_opt;
+	int size;
 
 	/* parse_err will be a string of the faulting option */
 	if (!state->parse_err)
@@ -45,8 +79,18 @@
 		max_arg_len = max((int)strlen(sb_opt[i]->flag), max_arg_len);
 	max_noarg_len = max_arg_len + 7;
 
+	/* Sort the options */
+	size = sizeof(*sorted_opt) * num_options;
+	sorted_opt = malloc(size);
+	if (!sorted_opt) {
+		printf("No memory to sort options\n");
+		os_exit(1);
+	}
+	memcpy(sorted_opt, sb_opt, size);
+	qsort(sorted_opt, num_options, sizeof(*sorted_opt), h_compare_opt);
+
 	for (i = 0; i < num_options; ++i) {
-		struct sandbox_cmdline_option *opt = sb_opt[i];
+		struct sandbox_cmdline_option *opt = sorted_opt[i];
 
 		/* first output the short flag if it has one */
 		if (opt->flag_short >= 0x100)