AArch32 gcc mode

[Vyacheslav Barinov]

Hello,

James Greenhalgh <james.greenhalgh@arm.com> writes:

> On Tue, Oct 28, 2014 at 05:29:15AM +0000, Slava Barinov wrote:
>> Hello,
>> 
>>   I work now with ARM64 CPUs and wanted to check AArch32 mode, I can see
>>   several mentions in GCC source code but can't find flag which switches on
>>   AArch32 code generation.
>> 
>>   Is it possible to make current GCC generate it?
>
> AArch32 is the 32-bit execution state in the ARMv8 architecture. It is
> closely related to the ARMv7 architecture, which in GCC is implemented as
> the "arm" target. Code generation for the AArch64 execution state of the
> ARMv8 architecture is implemented as the "aarch64" target.
>
> GCC has a model whereby the compiler can be built for only one target at
> any time, so there is no flag which will generate AArch32 code from an
> AArch64 compiler. You will need a compiler built to target "arm".
>
> For your use case that will mean installing two cross-compilers, one for
> (for example) arm-none-linux-gnueabi, and one for aarch64-none-linux-gnu.
>
> Thanks,
> James

  That was the first thing I tried and it works partially.
  But my initial idea was to use armv8 hardware extensions like accelerated
  crypto engine.

  Will setting CPU model to armv8 in arm-none-linux-gnueabi toolchain make it
  possible to use all its features in 32bit code?

Best Regards,
Vyacheslav Barinov