u-boot.git/lib/tiny-printf.c, branch v2018.11-rc3

SPDX: Convert all of our single license tags to Linux Kernel style

2018-05-07T13:34:12+00:00

When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini

Consolidate __assert_failed into one implementation

2018-04-28T22:32:23+00:00

We had two implementations of __assert_failed which were almost identical,
combine them into one.

Signed-off-by: Alex Kiernan

spl: Disable printf if not required

2018-04-28T22:32:23+00:00

Now we have a guard for printf, disable it in the build if it's not
selected.

Signed-off-by: Alex Kiernan

tiny-printf: Add support for %p format

2017-04-13T13:41:09+00:00

Add support for %p, %pa[p], %pM, %pm and %pI4 formats to tiny-printf.
%pM and %pI4 are widely used by SPL networking stack and is required if
networking support is desired in SPL.
%p, %pa and %pap are mostly used by debug prints and hence supported
only when DEBUG is enabled.

Before this patch:
$ size spl/u-boot-spl
   text	   data	    bss	    dec	    hex	filename
  99325	   4899	 218584	 322808	  4ecf8	spl/u-boot-spl

After this patch (with CONFIG_SPL_NET_SUPPORT):
$ size spl/u-boot-spl
   text	   data	    bss	    dec	    hex	filename
  99666	   4899	 218584	 323149	  4ee4d	spl/u-boot-spl

So, this patch adds ~350 bytes to code size.

If CONFIG_SPL_NET_SUPPORT is not enabled, this adds ~25 bytes.

If CONFIG_USE_TINY_PRINTF is disabled then:
$ size spl/u-boot-spl
  text	   data	    bss	    dec	    hex	filename
 101116	   4899	 218584	 324599	  4f3f7	spl/u-boot-spl

So, there is still ~1.4K space saved even with support for %pM/%pI4.

Compiler used is to build is:
arm-linux-gnueabihf-gcc (Linaro GCC 6.2-2016.11) 6.2.1 20161016

Signed-off-by: Vignesh R 
Reviewed-by: Tom Rini 
Reviewed-by: Simon Glass

tiny-printf: add static to locally used functions

2017-03-15T00:40:22+00:00

These two functions are only used in lib/tiny-printf.c .

Signed-off-by: Masahiro Yamada 
Tested-by: Andreas Färber 
Reviewed-by: Stefan Roese

SPL: tiny-printf: ignore "-" modifier

2017-01-04T15:37:41+00:00

tiny-printf does not know about the "-" modifier, which aligns numbers.
This is used by some SPL code, but as it's purely cosmetical, we just
ignore this modifier here to avoid changing correct printf strings.

Signed-off-by: Andre Przywara 
Reviewed-by: Simon Glass 
Reviewed-by: Jagan Teki

SPL: tiny-printf: add "l" modifier

2017-01-04T15:37:40+00:00

tiny-printf does not know about the "l" modifier so far, which breaks
the crash dump on AArch64, because it uses %lx to print the registers.
Add an easy way of handling longs correctly.

Using a relatively decent compiler (GCC 5.3.0) this does _not_ increase
the code size of tiny-printf.o for 32-bit builds (where long and int
are actually the same), actually it looses three (ARM Thumb2) instructions
from the actual SPL (numbers for orangepi_plus_defconfig):
  text    data     bss     dec     hex filename
   758       0       0     758     2f6 spl/lib/tiny-printf.o	before
 18839     488     232   19559    4c67 spl/u-boot-spl		before
   758       0       0     758     2f6 spl/lib/tiny-printf.o	after
 18833     488     232   19553    4c61 spl/u-boot-spl		after

This adds some substantial amount of code to a 64-bit build, though:
(taken after a later commit, which enables the ARM64 SPL build for sunxi)
  text    data     bss     dec     hex filename
  1542       0       0    1542     606 spl/lib/tiny-printf.o	before
 25830     392     360   26582    67d6 spl/u-boot-spl		before
  1758       0       0    1758     6de spl/lib/tiny-printf.o	after
 26040     392     360   26792    68a8 spl/u-boot-spl		after

Signed-off-by: Andre Przywara 
Reviewed-by: Simon Glass 
Reviewed-by: Jagan Teki

tiny-printf: Adjust to avoid using data section

2016-08-08T17:32:59+00:00

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 
Reviewed-by: Tom Rini 
Reviewed-by: Stefan Roese

tiny-printf: Support assert()

2016-07-15T02:40:24+00:00

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

SPL: tiny-printf: avoid any BSS usage

2016-07-08T16:50:34+00:00

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