arm: introduce raw console device

arch/arm/kernel/Makefile

@@ -83,6 +83,7 @@ endif
 head-y			:= head$(MMUEXT).o
 obj-$(CONFIG_DEBUG_LL)	+= debug.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
+obj-$(CONFIG_RAW_PRINTK)	+= raw_printk.o
 obj-$(CONFIG_IPIPE)	+= ipipe.o
 obj-$(CONFIG_IPIPE_ARM_KUSER_TSC) += ipipe_tsc.o ipipe_tsc_asm.o
 

arch/arm/kernel/raw_printk.c

+#include <linux/kernel.h>
+#include <linux/console.h>
+#include <linux/init.h>
+
+void printch(int);
+
+static void raw_console_write(struct console *co,
+			      const char *s, unsigned count)
+{
+	while (count-- > 0) {
+		if (*s == '\n')
+			printch('\r');
+		printch(*s++);
+	}
+}
+
+static struct console raw_console = {
+	.name		= "rawcon",
+	.write		= raw_console_write,
+	.write_raw	= raw_console_write,
+	.flags		= CON_PRINTBUFFER | CON_RAW,
+	.index		= -1,
+};
+
+static int __init raw_console_init(void)
+{
+	register_console(&raw_console);
+
+	return 0;
+}
+
+console_initcall(raw_console_init);