On Tue,  7 May 2013 09:39:55 -0500 Robin Holt [off-list ref] wrote:

Merge together the unicore32, arm, and x86 reboot= command line
parameter handling.

...

+static int __init reboot_setup(char *str)
+{
+	for (;;) {
+		/*
+		 * Having anything passed on the command line via
+		 * reboot= will cause us to disable DMI checking
+		 * below.
+		 */
+		reboot_default = 0;
+
+		switch (*str) {
+#if defined(CONFIG_X86) || defined(CONFIG_X86_64)
+		case 'w':
+			reboot_mode = REBOOT_WARM;
+			break;
+
+		case 'c':
+			reboot_mode = REBOOT_COLD;
+			break;
+
+#ifdef CONFIG_SMP
+		case 's':
+			if (isdigit(*(str+1))) {
+				reboot_cpu = (int) (*(str+1) - '0');
+				if (isdigit(*(str+2)))
+					reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
+			}

Boy, that's some weird stuff.

What's wrong with doing

			if (isdigit(str[1])) {
				reboot_cpu = str[1] - '0';
				if (isdigit(str[2]))
					reboot_cpu = reboot_cpu * 10 +
							str[2] - '0';
			}

?

But it's still nonsense - we should eliminate its
you-have-less-than-101-CPUs restriction by using, you know, atoi().