[MIPS] Qemu: Add early printk, your friend in a cold night.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 26 insertions, 0 deletions

diff --git a/arch/mips/qemu/q-console.c b/arch/mips/qemu/q-console.c
new file mode 100644
index 000000000000..81101ae5017a
--- /dev/null
+++ b/arch/mips/qemu/q-console.c
@@ -0,0 +1,26 @@
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/serial_reg.h>
+#include <asm/io.h>
+
+#define PORT(offset) (0x3f8 + (offset))
+
+static inline unsigned int serial_in(int offset)
+{
+	return inb(PORT(offset));
+}
+
+static inline void serial_out(int offset, int value)
+{
+	outb(value, PORT(offset));
+}
+
+int prom_putchar(char c)
+{
+	while ((serial_in(UART_LSR) & UART_LSR_THRE) == 0)
+		;
+
+	serial_out(UART_TX, c);
+
+	return 1;
+}