We can pass all the variables down to the functions that need them, and
then everything is on the stack. This is safer than using the data section.

At least on firefly-rk3288, the code size is the same and the data size is
12 bytes smaller:

before:
  18865	   2636	     40	  21541	   5425	b/firefly-rk3288/spl/u-boot-spl
after:
  18865	   2624	     40	  21529	   5419	b/firefly-rk3288/spl/u-boot-spl

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Stefan Roese <sr@denx.de>

At present assert() is not supported with tiny-printf, so when DEBUG is
enabled a build error is generated for each assert().

Add an __assert_fail() function to correct this. It prints a message and
then hangs.

Signed-off-by: Simon Glass <sjg@chromium.org>

As printf calls may be executed quite early, we should avoid using any
BSS stored variables, since some boards put BSS in DRAM, which may not
have been initialised yet.
Explicitly mark those "static global" variables as belonging to the
.data section, to keep tiny-printf clear of any BSS usage.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>

vprintf is used by panic() which is used in various SPL paths on some
boards.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
Reviewed-by: Simon Glass <sjg@chromium.org>

This current code passes the variable arguments list to sprintf(). This is
not correct. Fix it by calling _vprintf() directly.

This makes firefly-rk3288 boot again.

Fixes: abeb272d ("tiny-printf: Support snprintf()")
Reviewed-by: Stefan Roese <sr@denx.de>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Simon Glass <sjg@chromium.org>

Add a simple version of this function for SPL. It does not check the buffer
size as this would add to the code size.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Stefan Roese <sr@denx.de>
Cc: Tom Rini <trini@konsulko.com>
Cc: lesne@alse-fr.com
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Sylvain Lesne <lesne@alse-fr.com>
Tested-by: Sylvain Lesne <lesne@alse-fr.com>

Add a simple version of this function for SPL. It does not check the buffer
size as this would add to the code size.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>

- Rename 'w' to 'width' to make it more obvious what it is used for
- Use bool and int types instead of char to avoid register-masking on
32-bit machines

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>

At present this does not print zero values in numeric format (hex and
decimal). Add a special case for this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>

Add a check for NULL strings to avoid printing junk to the console.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>

Implement both printf and vprintf for a bit more flexibility, e.g.
allows the panic() function to work with tiny-printf.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>

With this patch now, the tiny printf() function also supports numbers
bigger than 0xffff. Additionally the code is simplified a bit and
some static variables are moved to function parameters. Also the
upper case hex variable output support is removed, as its not really
needed in this simple printf version. And removing it reduces the
complexity and the code size again a bit.

Here the new numbers, again on the db-mv784mp-gp (Armada XP):

Without this patch:
  56542   18536    1956   77034   12cea ./spl/u-boot-spl

With this patch:
  56446   18536    1936   76918   12c76 ./spl/u-boot-spl

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>

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>