cbmem: add and use a function to dump console buffer

The new function can be compiled in only when serial console is
disabled.

When invoked, this function initializes the serial interface and dumps
the contents of the CBMEM console buffer to serial output.

BRANCH=none
BUG=chromium:475347
TEST=compiled for different platforms with and without serial console
     enabled. No actual test of this function yet.

Change-Id: Ia8d16649dc9d09798fa6970f2cfd893438e00dc5
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: a38a8254dd788ad188ba2509b9ae117d6f699579
Original-Change-Id: Ib85759a2727e31ba1ca21da7e6c346e434f83b52
Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/265293
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/9984
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/lib/cbmem_console.c b/src/lib/cbmem_console.c
index 628d3b9..9d292bf 100644
--- a/src/lib/cbmem_console.c
+++ b/src/lib/cbmem_console.c
@@ -19,6 +19,7 @@
 
 #include <console/console.h>
 #include <console/cbmem_console.h>
+#include <console/uart.h>
 #include <cbmem.h>
 #include <arch/early_variables.h>
 #include <symbols.h>
@@ -236,5 +237,21 @@
 	init_console_ptr(cbm_cons_p, size, flags);
 }
 
+#if IS_ENABLED(CONFIG_CONSOLE_CBMEM_DUMP_TO_UART)
+void cbmem_dump_console(void)
+{
+	struct cbmem_console *cbm_cons_p;
+	int cursor;
+
+	cbm_cons_p = current_console();
+	if (!cbm_cons_p)
+		return;
+
+	uart_init(0);
+	for (cursor = 0; cursor < cbm_cons_p->buffer_cursor; cursor++)
+		uart_tx_byte(0, cbm_cons_p->buffer_body[cursor]);
+}
+#endif
+
 /* Call cbmemc_reinit() at CAR migration time. */
 CAR_MIGRATE(cbmemc_reinit)