Re: [PATCH v2 0/3] Rust enablement for AArch64

[Boqun Feng <boqun.feng@gmail.com>]

On Tue, Jun 06, 2023 at 03:56:03PM +0100, Jamie Cunliffe wrote:
> Enable Rust support for the AArch64 architecture.
> 

With the following diff on the whole series:

	diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
	index 4a2c807d65db..4562a8173e90 100644
	--- a/arch/arm64/Makefile
	+++ b/arch/arm64/Makefile
	@@ -41,7 +41,7 @@ KBUILD_CFLAGS += -mgeneral-regs-only  \
	 KBUILD_CFLAGS  += $(call cc-disable-warning, psabi)
	 KBUILD_AFLAGS  += $(compat_vdso)

	-KBUILD_RUSTFLAGS += --target aarch64-unknown-none -C target-feature="-neon,-fp-armv8"
	+KBUILD_RUSTFLAGS += --target aarch64-unknown-none -C target-feature="-neon"

	 KBUILD_CFLAGS  += $(call cc-option,-mabi=lp64)
	 KBUILD_AFLAGS  += $(call cc-option,-mabi=lp64)

I've built with RUST=y and boot it in one ARM64 Hyper-V VM. Also I tried
load/unload rust_minimal and rust_print modules, they all worked.

Tested-by: Boqun Feng <boqun.feng@gmail.com>

Regards,
Boqun
	

> The first patch enables the basic building of Rust for AArch64. Since
> v1 this has been rewritten to avoid the use of a target.json file for
> AArch64 and use the upstream rustc target definition. x86-64 still
> uses the target.json approach though.
> 
> The second patch enables the PAC ret and BTI options in the Rust build
> flags to match the options that are used when building C.
> 
> The third patch disables Rust support when building for big
> endian. Currently there is no `aarch64_be-unknown-none` target which
> would allow this. Support for this can come at a later time either by
> using the target.json approach, or upstreaming a new target definition
> to rustc (preferred). We also might be able to use the
> `aarch64_be-unknown-linux-gnu` target, however, this can be done at a
> later time.  It's worth noting that in Makefile.clang, it's
> recommended for arch/{arch}/Makefile to set the endianness based on
> arguments rather than the target triple. It's currently not possible
> to do this with rustc, a different target triple has to be used.
> 
> 
> Jamie Cunliffe (3):
>   arm64: rust: Enable Rust support for AArch64
>   arm64: rust: Enable PAC support for Rust.
>   arm64: Restrict Rust support to little endian only.
> 
>  Documentation/rust/arch-support.rst | 1 +
>  Makefile                            | 1 -
>  arch/arm64/Kconfig                  | 1 +
>  arch/arm64/Makefile                 | 4 ++++
>  arch/x86/Makefile                   | 1 +
>  rust/Makefile                       | 6 +++++-
>  scripts/Makefile                    | 5 +++--
>  scripts/generate_rust_target.rs     | 4 +++-
>  8 files changed, 18 insertions(+), 5 deletions(-)
> 
> -- 
> 2.30.2
> 
>