[U-Boot] powerpc: FOO uses hard float, BAR uses soft float

[Kumar Gala]

On Dec 8, 2011, at 4:09 PM, Wolfgang Denk wrote:

> Hi,
> 
> I'm looking for help to get rid of linker warnigns like these:
> 
> -> ./MAKEALL sequoia
> Configuring for sequoia - Board: sequoia, Options: SEQUOIA
> powerpc-linux-ld: Warning: 20010226-1.o uses hard float, libpostpowerpcfpu.o uses soft float
> powerpc-linux-ld: Warning: acc1.o uses hard float, libpostpowerpcfpu.o uses soft float
> powerpc-linux-ld: Warning: /opt/eldk-5.1/powerpc/sysroots/powerpc-linux/usr/lib/powerpc-linux/4.6.1/libgcc.a(darwin-ldouble.o) uses hard float, u-boot uses soft float
> 
> These warnings are cause by the fact that we always build U-Boot with
> "-msoft-float", but boards that have POST enabled may pull in the FPU
> test code, which naturally will have to be compiled with
> "-mhard-float" instead.
> 
> 
> Is there any way to silence these warnings (ideally only for these
> specific set of files, where we know they are to be expected) ?
> 
> 
> I tried playing tricks to get rid of them - the information about
> using the FPU is envoded in the ".gnu.attributes" section of the ELF
> file:
> 
> -> readelf -A /work/wd/tmp-ppc/post/lib_powerpc/fpu/acc1.o
> Attribute Section: gnu
> File Attributes
>  Tag_GNU_Power_ABI_FP: Hard float
> 
> -> readelf -e /work/wd/tmp-ppc/post/lib_powerpc/fpu/acc1.o | grep gnu.attributes
>  [129] .gnu.attributes   LOOS+ffffff5    00000000 004e5c 000010 00      0   0  1
> 
> 
> We can remove this information using brute force, like
> 
> 	${CROSS_COMPILE}objcopy -R .gnu.attributes
> 
> which indeed gets rid of most of the warnings - but it will still
> result in the
> 
> powerpc-linux-ld: Warning: /opt/eldk-5.1/powerpc/sysroots/powerpc-linux/usr/lib/powerpc-linux/4.6.1/libgcc.a(darwin-ldouble.o) uses hard float, u-boot uses soft float
> 
> warning.
> 
> 
> Anybody any ideas?
> 

Look at commit, we dealt with this in the past

commit ce82ff05388b5ddafdf6082ef0776cce72c40b1c
Author: Yuri Tikhonov <yur at emcraft.com>
Date:   Sat Dec 20 14:54:21 2008 +0300

    FPU POST: fix warnings when building with 2.18 binutils

Also:

commit e009cdeb63308f291c54b173484401aab4a3fe54
Author: Kumar Gala <galak at kernel.crashing.org>
Date:   Tue Jan 25 03:00:08 2011 -0600

    powerpc: Fix FPU post related link warnings

- k