[Buildroot] [PATCH v2 1/1] toolchain/toolchain-buildroot: PPC64(LE) support in musl requires ALTIVEC

[Vincent Fazio <vfazio@xes-inc.com>]

Romain,

On 2/4/20 10:11 AM, Romain Naour wrote:
> Hi Vincent,
>
> Le 31/01/2020 ? 16:39, Vincent Fazio a ?crit?:
>> musl currently assumes all PPC64(LE) CPUs support ALTIVEC instructions.
>>
>> However, there are exceptions (such as the e5500) for which musl builds
>> ultimately generate illegal instructions for the targets.
>>
>> Disable musl if the PPC64(LE) CPU does not support ALTIVEC instructions.
>>
>> This patch addresses the issues seen here:
>>    https://gitlab.com/kubu93/toolchains-builder/-/jobs/418092743
>>    https://gitlab.com/kubu93/toolchains-builder/-/jobs/418092744
> I reported this issue to the musl mailing list. I'm not sure the e5500 support
> will be added in the end.
>
> https://www.openwall.com/lists/musl/2020/02/03/10
>
>> Signed-off-by: Vincent Fazio <vfazio@xes-inc.com>
>> ---
>>   toolchain/toolchain-buildroot/Config.in | 6 ++++--
>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/toolchain/toolchain-buildroot/Config.in b/toolchain/toolchain-buildroot/Config.in
>> index a980f766ac..09a46822c9 100644
>> --- a/toolchain/toolchain-buildroot/Config.in
>> +++ b/toolchain/toolchain-buildroot/Config.in
>> @@ -83,8 +83,10 @@ config BR2_TOOLCHAIN_BUILDROOT_MUSL
>>   	bool "musl"
>>   	depends on BR2_aarch64	   || BR2_arm   || BR2_armeb   || BR2_i386 || \
>>   		   BR2_microblaze  || BR2_mips  || BR2_mipsel  || BR2_mips64 || \
>> -		   BR2_mips64el    || BR2_or1k  || BR2_powerpc || BR2_powerpc64 || \
>> -		   BR2_powerpc64le || BR2_RISCV_64 || BR2_sh   || BR2_x86_64
>> +		   BR2_mips64el    || BR2_or1k  || BR2_powerpc || BR2_RISCV_64 || \
>> +		   BR2_sh	   || BR2_x86_64 || \
>> +		   ((BR2_powerpc64 || BR2_powerpc64le) && BR2_POWERPC_CPU_HAS_ALTIVEC)
>> +		   # musl assumes all PPC64 targets support ALTIVEC instructions
> Well, previously the architectures was sorted alphabetically. Please keep it.
>
> You can add the dependency this way:
>
> # musl assumes all PPC64 targets support ALTIVEC instructions
> depends on !(BR2_powerpc64 || BR2_powerpc64le) || BR2_POWERPC_CPU_HAS_ALTIVEC
Ack, i didn't even notice they were alpha-sorted. i'll fix this in v3. 
Thanks
> Best regards,
> Romain
>
>>   	depends on !BR2_powerpc_SPE # not supported, build breaks
>>   	# sh2 nommu is supported by musl, but we don't have support
>>   	# for it in Buildroot.
>>
-- 
Vincent Fazio
Embedded Software Engineer - Linux
Extreme Engineering Solutions, Inc
http://www.xes-inc.com