lib/tiny-printf.c: Add tiny printf function for space limited environments

This patch adds a small printf() version that supports all basic formats.
Its intented to be used in U-Boot SPL versions on platforms with very
limited internal RAM sizes.

To enable it, just define CONFIG_USE_TINY_PRINTF in your defconfig. This
will result in the SPL using this tiny function and the main U-Boot
still using the full-blown printf() function.

This code was copied from:
http://www.sparetimelabs.com/printfrevisited
With mostly only coding style related changes so that its checkpatch
clean.

The size reduction is about 2.5KiB. Here a comparison for the db-mv784mp-gp
(Marvell AXP) SPL:

Without this patch:
  58963   18536    1928   79427   13643 ./spl/u-boot-spl

With this patch:
  56542   18536    1956   77034   12cea ./spl/u-boot-spl

Note:
To make it possible to compile tiny-printf.c instead of vsprintf.c when
CONFIG_USE_TINY_PRINTF is defined, the functions printf() and vprintf() are
moved from common/console.c into vsprintf.c in this patch.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Tom Rini <trini@konsulko.com>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>

1 files changed, 4 insertions, 36 deletions

diff --git a/examples/api/libgenwrap.c b/examples/api/libgenwrap.c
index c1afa5b..ba51007 100644
--- a/examples/api/libgenwrap.c
+++ b/examples/api/libgenwrap.c
@@ -16,46 +16,14 @@
 
 #include "glue.h"
 
-/*
- * printf() and vprintf() are stolen from u-boot/common/console.c
- */
-int printf (const char *fmt, ...)
-{
-	va_list args;
-	uint i;
-	char printbuffer[256];
-
-	va_start (args, fmt);
-
-	/* For this to work, printbuffer must be larger than
-	 * anything we ever want to print.
-	 */
-	i = vsprintf (printbuffer, fmt, args);
-	va_end (args);
-
-	/* Print the string */
-	ub_puts (printbuffer);
-	return i;
-}
-
-int vprintf (const char *fmt, va_list args)
+void putc(const char c)
 {
-	uint i;
-	char printbuffer[256];
-
-	/* For this to work, printbuffer must be larger than
-	 * anything we ever want to print.
-	 */
-	i = vsprintf (printbuffer, fmt, args);
-
-	/* Print the string */
-	ub_puts (printbuffer);
-	return i;
+	ub_putc(c);
 }
 
-void putc (const char c)
+void puts(const char *s)
 {
-	ub_putc(c);
+	ub_puts(s);
 }
 
 void __udelay(unsigned long usec)