[yocto] build a toolchain compiler with ARM hard-float support

[Mark Hatle]

On 9/29/16 5:31 AM, Richard Purdie wrote:
> On Thu, 2016-09-29 at 09:10 +0000, Karim ATIKI wrote:
>> Hi,
>>
>> I'm using Poky Jethro to build on Toradex Colibri-T20 (armv7).
>>
>> I want to build my own SDK Installer to have  a toolchain and a
>> sysroot.
>>
>> Currently, I realied that the toolchain installer files do not
>> provide an arm-poky-linux-gnuabi compiler with hard-float support.
>> For example, while compiling my project:
>>
>> /opt/poky/2.0.1/sysroots/armv7a-vfp-neon-poky-linux-
>> gnueabi/usr/include/gnu/stubs.h:10:29: fatal error: gnu/stubs-hard.h: 
>> No such file or directory
>>
>> Therefore:
>>
>>  How to be sure that the compiler generated by "bitbake -c
>> populate_sdk" will support hard-float ? Is there a configuration file
>> ?
> 
> You need to choose a MACHINE which uses hard-float.

The machine configuration file should be setting the 'DEFAULTTUNE' variable to
an appropriate ISA and ABI (hard float) for your configuration.  If it is not,
you may have to create your own variant and change the DEFAULTTUNE setting --
assuming the board supports the necessary hard float components.  (And yes,
there are some armv7a variants that people removed the VFP instructions from --
even though it's theoretically against spec.)

--Mark

> Cheers,
> 
> Richard
>