[Buildroot] [Bug 4634] New: Bigendian binary is output even if it is configured to output little endian

[Michael S. Zick <minimod@morethan.org>]

On Sat December 17 2011, bugzilla at busybox.net wrote:
> https://bugs.busybox.net/show_bug.cgi?id=4634
> 
>            Summary: Bigendian binary is output even if it is configured to
>                     output little endian
>            Product: buildroot
>            Version: 2011.11
>           Platform: PC
>         OS/Version: Linux
>             Status: NEW
>           Severity: major
>           Priority: P5
>          Component: Other
>         AssignedTo: unassigned at buildroot.uclibc.org
>         ReportedBy: matusita at k-micro.com
>                 CC: buildroot at uclibc.org
>    Estimated Hours: 0.0
> 
> 
> I set build options as below in "make menuconfig" to build root filesystem:
>   Target Architecture (mipsel)
>   Target Architecture Variant (mips 32r2)
>   Toolcain-Toolchain type (External toolchain)
>   Toolcain-Toolchain (CodeSourcery MIPS 2011.03)
> 
> I expected that little enfian binary will be output because "mipsel" is
> selected. But it was big endian.
> I confirmed it by objdump with "-f" option like below.
> 
>   % mips-linux-gnu-objdump -f busybox
>     busybox:     file format elf32-tradbigmips      <-- Big endian !!!
>     architecture: mips:isa32r2, flags 0x00000112:
>     EXEC_P, HAS_SYMS, D_PAGED
>     start address 0x00403f00
> 
> So, I saw following file:
>   toolchain/toolchain-external/ext-tool.mk
> 
> And I understand that this script get libraries' location by calling
> (prefix)-gcc with following options:
>   -print-sysroot
>   -print-file-name=libc.a
> 
> But as for this toolchain(CodeSourcery MIPS 2011.03), it is need to set "-EL"
> option as well to get correct location of little endian libraries.
> 

I think that the endian default is a gcc build-time option and some builders
do select (or it defaults to) little endian.

But the CS toolchains do default to big endian.
Too be more general purpose, perhaps there should also be a "knob" to pass
-mno-mips16 since the gcc default is to produce mixed 16/32 (or 16/64) bit
code and the mips16e decoder is not a core requirement.

http://openplayer.org/resource/tutorials/57-cs-multi-library-tour.html

Mike