Provide MRC with a console printing callback function

Let memory initialization code use the coreboot romstage console. This
simplifies the code and makes sure that all output is available in
/sys/firmware/log.

The pei_data structure is modified to allow passing the console output
function pointer. Romstage console_tx_byte() is used for this purpose.

Change-Id: I722cfcb9ff0cf527c12cb6cac09d77ef17b588e0
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: http://review.coreboot.org/1823
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martin@se-eng.com>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/arch/x86/lib/romstage_console.c

@@ -29,7 +29,7 @@
 #include <console/ne2k.h>
 #endif
 
-static void console_tx_byte(unsigned char byte)
+void console_tx_byte(unsigned char byte)
 {
 	if (byte == '\n')
 		console_tx_byte('\r');

src/include/console/console.h

@@ -38,7 +38,6 @@
 #endif
 
 #ifndef __PRE_RAM__
-void console_tx_byte(unsigned char byte);
 void console_tx_flush(void);
 unsigned char console_rx_byte(void);
 int console_tst_byte(void);
@@ -68,6 +67,7 @@ extern int console_loglevel;
 
 #ifndef __ROMCC__
 void console_init(void);
+void console_tx_byte(unsigned char byte);
 void post_code(u8 value);
 /* this function is weak and can be overridden by a mainboard function. */
 void mainboard_post(u8 value);

src/northbridge/intel/sandybridge/pei_data.h

@@ -30,7 +30,8 @@
 #ifndef PEI_DATA_H
 #define PEI_DATA_H
 
-#define PEI_VERSION 1
+typedef void (*tx_byte_func)(unsigned char byte);
+#define PEI_VERSION 2
 struct pei_data
 {
 	uint32_t pei_version;
@@ -93,6 +94,7 @@ struct pei_data
 	 * spd_address for a given "DIMM".
 	 */
 	uint8_t spd_data[4][256];
+	tx_byte_func tx_byte;
 } __attribute__((packed));
 
 #endif

src/northbridge/intel/sandybridge/raminit.c

@@ -241,6 +241,9 @@ void sdram_initialize(struct pei_data *pei_data)
 		hlt();
 	}
 
+	/* Pass console handler in pei_data */
+	pei_data->tx_byte = console_tx_byte;
+
 	/* Locate and call UEFI System Agent binary. */
 	entry = (unsigned long)cbfs_find_file("mrc.bin", 0xab);
 	if (entry) {