Re: building a multilb ARM toolchain for softfp and hard float

[Peter Barada <peter dot barada at logicpd dot com>]

On 09/18/2012 10:06 PM, Zhenqiang Chen wrote:
> On 19 September 2012 01:54, Peter Barada <peter.barada@logicpd.com> wrote:
>> I'm having a tough time trying to come up with a newer toolchain for
>> cortex-a8 that has support for both hard and soft floating point.  I've
>> tried building a toolchain using
>> crosstool-ng-linaro-1.13.1-2012.08-20120827.tar.bz2 but when I try to
>> compile u-boot it complains with:
> Linaro prebuilt toolchain does support both hard and soft floating
> point. You can get it from
> https://launchpad.net/linaro-toolchain-binaries/+milestone/2012.08
>
> try: ./arm-linux-gnueabihf-gcc -print-multi-lib
>
> The default configure is --with-arch=armv7-a --with-tune=cortex-a9
> --with-fpu=vfpv3-d16 --with-float=hard  --with-mode=thumb
>
> To use soft floating, you need options: -marm -march=armv4t -mfloat-abi=soft.
>
> In your case, please try to change  -march=armv5 to "-march=armv4t"
>
> If you want to change to configure to cortex-a8 and armv5. You need
> * Change cortex-a9 to cortex-a8 in
> samples/linaro-arm-linux-gnueabihf/crosstool.config
> * Change armv4t to armv5 in
> contrib/linaro/patches/gcc/linaro-4.7-2012.08/multilib.patch,
>
> Then follow the instructions to rebuild the toolchain
> (contrib/linaro/doc/README.txt)
>
> BTW: crosstool-ng-linaro does not support multilib for eglibc. It uses
> the prebuilt sysroot from Ubuntu Precise. If it does not work for you,
> please use the latest crosstool-ng from http://crosstool-ng.org/.
Thanks for the response. So far things are building, taking a bit of
work in LTIB to use this toolchain to build all its packages.  I'll
shove the result off the cliff when I it (finally) completes building to
see if it actually runs.

One problem is when running LTIB's base_libs.spec script to create an
RPM of the toolchain libraries to install on the target rootfs, RPM
fails with:

error: failed dependencies:
    ld-linux.so.3(GLIBC_2.4)   is needed by base_libs-1.2-1

Digging into it, RPM can't find ld-linux.so.3 since ld-linux.so.3 is a
symbolic link to ld-linux-armhf.so.3, but libattr.so.1.1.0 and
libacl.so.1.1.0 require ld-linux.so.3 (but no other shared object
library), and no library claims to provide ld-linux.so.3.

Why do libacl and libattr require ld-linux.so.3, but libc.so requires
ld-2.15.s0?  Is there anyway to modify the build such that libacl and
libattr require ld-2.15.so (instead of ld-linux.so.3) to fix this?

Thanks in advance!

-- 
Peter Barada
peter.barada@logicpd.com


--
For unsubscribe information see http://sourceware.org/lists.html#faq