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

[Zhenqiang Chen <zhenqiang dot chen at linaro dot org>]

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!
-Zhenqiang

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