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

Boqun Feng
2023-06-09T18:36:11Z

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