Re: some question about aarch32 for ARM64

From: Catalin Marinas
Date: Mon Feb 23 2015 - 08:27:56 EST


On Mon, Feb 23, 2015 at 12:28:57PM +0000, loody wrote:
> I follow below instructions to compile a simple c file as aarch32 but in vain.
>
> https://gcc.gnu.org/onlinedocs/gcc-4.9.1/gcc/AArch64-Options.html#AArch64-Options

On the above link, there are no instructions on how to compile an
AArch32 application with the AArch64 compiler. You need an AArch32 gcc
(e.g. arm-linux-gnu-gcc, not aarch64-linux-gnu-gcc).

> I saw there are aarch32 support in arm64 kernel porting.

Yes, that's to support AArch32 binaries (ARMv8/v7/...).

> Would you mind to let us know how to get aarch32 ELF for running on
> ARM64 processors?

Just use the right compiler.

> PS:Below is my compile error message:
> #aarch64-linux-gnu-gcc -mabi=ilp32 test.c

-mabi=ilp32 is entirely different from an AArch32 compiler. The above
still generates AArch64 but with the ILP32 ABI (sizeof int/long/pointer
is 32-bit).

--
Catalin
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