video: add video_printf

video_printf prints strings on the screen with specified foreground and
background color.

BUG=none
BRANCH=smaug
TEST=verified messages printed on Smaug

Change-Id: I619625f7d4c5bc19cd9de64a0ba07899cf9ba289
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Original-Commit-Id: e0ac4cb4c0d43b40f5c8f8f5a90eac45b0263b77
Original-Reviewed-on: https://chromium-review.googlesource.com/290130
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-(cherry picked from commit 75ea2c025d629c8fabc0cb859c4e8ab8ba6ce6e3)
Original-Change-Id: Ief6d1fc820330b54f37ad9260cf3119853460b70
Original-Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/290373
Reviewed-on: http://review.coreboot.org/11407
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

payloads/libpayload/drivers/video/video.c

@@ -162,6 +162,27 @@ void video_console_putchar(unsigned int ch)
 	video_console_fixup_cursor();
 }
 
+void video_printf(int foreground, int background, const char *fmt, ...)
+{
+	int i = 0, len;
+	char str[200];
+
+	va_list ap;
+	va_start(ap, fmt);
+	len = vsnprintf(str, ARRAY_SIZE(str), fmt, ap);
+	va_end(ap);
+	if (len <= 0)
+		return;
+
+	foreground &= 0xf;
+	foreground <<= 8;
+	background &= 0xf;
+	background <<= 12;
+
+	while (str[i])
+		video_console_putchar(str[i++] | foreground | background);
+}
+
 void video_console_get_cursor(unsigned int *x, unsigned int *y, unsigned int *en)
 {
 	*x=0;

payloads/libpayload/include/libpayload.h

@@ -206,6 +206,11 @@ void video_console_clear(void);
 void video_console_cursor_enable(int state);
 void video_console_get_cursor(unsigned int *x, unsigned int *y, unsigned int *en);
 void video_console_set_cursor(unsigned int cursorx, unsigned int cursory);
+/*
+ * print characters on video console with colors. note that there is a size
+ * restriction for the internal buffer. so, output string can be truncated.
+ */
+void video_printf(int foreground, int background, const char *fmt, ...);
 /** @} */
 
 /**