Re: [PATCH v2 7/8] travis: Add ARM thumb target to tests

[Alexander Graf]

On 14.05.19 16:06, Leif Lindholm wrote:
> On Tue, May 14, 2019 at 06:32:06AM -0700, Alexander Graf wrote:
>>> But, wait...
>>> arm-linux-gnueabi is the softfloat (v5te) toolchain - if we want to
>>> test that, fine - but we definitely need to test arm-linux-gnueabihf.
>>>
>>> First of all, I would expect that this toolchain will not use T32
>>> (Thumb-2) instructions by default, so much of the code will end up
>>> being compiled as A32 anyway.
>>
>> Yeah, that's why we don't need to pass in -marm I guess. But I also
>> don't see an explicit hardfloat cross gcc on kernel.org?
>>
>>   https://mirrors.kernel.org/pub/tools/crosstool/files/bin/x86_64/8.1.0/
> Urgh.
> Yeah, so the default output of that toolchain gives
>   File Attributes
>   Tag_CPU_name: "5T"
>   Tag_CPU_arch: v5T
>   Tag_ARM_ISA_use: Yes
>   Tag_THUMB_ISA_use: Thumb-1
>
> In theory, you should be OK just adding
> "-mfloat-abi=hard -march=armv7-a+vfpv3-d16" to CFLAGS, since we're not
> using any toolchain-provided libraries:


In configure we're already forcing soft float, so there's little point
in adding these cflags :). In fact, when I do add them, I only get
configure errors because setting both -mhard-float and -msoft-float at
the same time confuses gcc.


Alex