console: Add printk helper for ChromeOS

Do not expose console_tx_flush() to ChromeOS as that function
is part of lower-level implementation.

Change-Id: I1e31662da88a60e83f8e5d307a4b53441c130aab
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/5347
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

src/console/printk.c

@@ -40,3 +40,11 @@ int do_printk(int msg_level, const char *fmt, ...)
 
 	return i;
 }
+
+#if CONFIG_CHROMEOS
+void do_vtxprintf(const char *fmt, va_list args)
+{
+	vtxprintf(console_tx_byte, fmt, args);
+	console_tx_flush();
+}
+#endif

src/include/console/console.h

@@ -82,6 +82,16 @@ static inline void printk(int LEVEL, const char *fmt, ...) {
 
 #endif /* defined(__PRE_RAM__) && !CONFIG_EARLY_CONSOLE */
 
+#if CONFIG_CHROMEOS
+/* FIXME: Collision of varargs with AMD headers without guard. */
+#include <console/vtxprintf.h>
+#if !defined(__PRE_RAM__) || CONFIG_EARLY_CONSOLE
+void do_vtxprintf(const char *fmt, va_list args);
+#else
+static inline void do_vtxprintf(const char *fmt, va_list args) {};
+#endif
+#endif
+
 #define print_emerg(STR)         printk(BIOS_EMERG,  "%s", (STR))
 #define print_alert(STR)         printk(BIOS_ALERT,  "%s", (STR))
 #define print_crit(STR)          printk(BIOS_CRIT,   "%s", (STR))

src/vendorcode/google/chromeos/vboot_loader.c

@@ -64,8 +64,7 @@ out:
 /* Helper routines for the vboot stub. */
 static void log_msg(const char *fmt, va_list args)
 {
-	vtxprintf(console_tx_byte, fmt, args);
+	do_vtxprintf(fmt, args);
-	console_tx_flush();
 }
 
 static void fatal_error(void)