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Merged
mkroening merged 2 commits into from
Sep 4, 2025
Merged

Add support for aarch64_be #476

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3bae807
CI: Add aarch64_be hello_world binary
Gelbpunkt Aug 22, 2025
37c4eb9
feat: Add support for aarch64_be
Gelbpunkt Aug 19, 2025
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9 changes: 6 additions & 3 deletions .github/workflows/ci.yml
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Original file line number Diff line number Diff line change
Expand Up @@ -42,7 +42,7 @@ jobs:
name: Run
strategy:
matrix:
target: [x86_64, aarch64, riscv64]
target: [x86_64, aarch64, aarch64_be, riscv64]
os: [ubuntu-latest, macos-latest, windows-latest]
include:
- target: x86_64
Expand Down Expand Up @@ -83,8 +83,11 @@ jobs:
- uses: actions/checkout@v5
with:
lfs: true
- name: Install stable Rust toolchain
uses: dtolnay/rust-toolchain@stable
- name: Install Rust toolchain
uses: dtolnay/rust-toolchain@master
with:
toolchain: ${{ matrix.target == 'aarch64_be' && 'nightly' || 'stable' }}
components: ${{ matrix.target == 'aarch64_be' && 'rust-src' || '' }}
- name: Dowload OpenSBI
if: matrix.target == 'riscv64'
run: |
Expand Down
3 changes: 3 additions & 0 deletions data/aarch64_be/hello_world
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10 changes: 7 additions & 3 deletions src/arch/aarch64/entry.rs
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Expand Up @@ -165,10 +165,13 @@ unsafe fn pre_init() -> ! {
or if loading and not setting them would be the appropriate action.
*/

#[cfg(target_endian = "big")]
let endian = SCTLR_EL1::EE::BigEndian + SCTLR_EL1::E0E::BigEndian;
#[cfg(target_endian = "little")]
let endian = SCTLR_EL1::EE::LittleEndian + SCTLR_EL1::E0E::LittleEndian;

SCTLR_EL1.write(
SCTLR_EL1::UCI::DontTrap
+ SCTLR_EL1::EE::LittleEndian
+ SCTLR_EL1::E0E::LittleEndian
+ SCTLR_EL1::WXN::Disable
+ SCTLR_EL1::NTWE::DontTrap
+ SCTLR_EL1::NTWI::DontTrap
Expand All @@ -181,7 +184,8 @@ unsafe fn pre_init() -> ! {
+ SCTLR_EL1::SA::Enable
+ SCTLR_EL1::C::Cacheable
+ SCTLR_EL1::A::Disable
+ SCTLR_EL1::M::Disable,
+ SCTLR_EL1::M::Disable
+ endian,
);

// Enter loader
Expand Down
2 changes: 0 additions & 2 deletions src/arch/aarch64/link.ld
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Expand Up @@ -2,8 +2,6 @@
* https://github.com/rust-embedded/rust-raspberrypi-OS-tutorials/blob/master/16_virtual_mem_part4_higher_half_kernel/src/bsp/raspberrypi/link.ld
*/

OUTPUT_FORMAT("elf64-littleaarch64")
OUTPUT_ARCH("aarch64")
Comment on lines -5 to -6

@mkroening mkroening Sep 3, 2025

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This seems to work, but do you happen to have any knowledge on where the default value comes from and what it is now?

@Gelbpunkt Gelbpunkt Sep 3, 2025

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No, I don't, but I imagine the linker is well aware of the architecture it is linking for and therefore doesn't need this explicit hint

ENTRY(_start)
phys = 0x40200000;

Expand Down
10 changes: 5 additions & 5 deletions xtask/src/ci/qemu.rs
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Expand Up @@ -63,8 +63,8 @@ impl Qemu {
}

let target = self.build.target();
let arch = target.arch();
let qemu = env::var("QEMU").unwrap_or_else(|_| format!("qemu-system-{arch}"));
let qemu = target.qemu();
let qemu = env::var("QEMU").unwrap_or_else(|_| format!("qemu-system-{qemu}"));
let program = if self.sudo { "sudo" } else { qemu.as_str() };
let arg = self.sudo.then_some(qemu.as_str());

Expand Down Expand Up @@ -96,7 +96,7 @@ impl Qemu {
"-append".to_string(),
format!("-freq {frequency}"),
]
} else if self.build.target() == Target::Aarch64 {
} else if matches!(self.build.target(), Target::Aarch64 | Target::Aarch64Be) {
vec!["-machine".to_string(), "virt,gic-version=3".to_string()]
} else if self.build.target() == Target::Riscv64 {
vec![
Expand Down Expand Up @@ -174,7 +174,7 @@ impl Qemu {
cpu_args
}
Target::X86_64Fc => panic!("unsupported"),
Target::Aarch64 => {
Target::Aarch64 | Target::Aarch64Be => {
let mut cpu_args = if self.accel {
todo!()
} else {
Expand Down Expand Up @@ -233,7 +233,7 @@ impl Qemu {
Target::X86_64Uefi => {
memory = memory.max(512);
}
Target::Aarch64 => {
Target::Aarch64 | Target::Aarch64Be => {
memory = memory.max(256);
}
Target::Riscv64 => {
Expand Down
32 changes: 29 additions & 3 deletions xtask/src/target.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -9,15 +9,18 @@ pub enum Target {
X86_64Fc,
X86_64Uefi,
Aarch64,
Aarch64Be,
Riscv64,
}

impl Target {
pub fn install(&self) -> xshell::Result<()> {
let sh = Shell::new()?;

let triple = self.triple();
cmd!(sh, "rustup target add {triple}").run()?;
if self.tier() <= 2 {
let triple = self.triple();
cmd!(sh, "rustup target add {triple}").run()?;
}

if self == &Self::X86_64 {
cmd!(sh, "rustup component add llvm-tools-preview").run()?;
Expand All @@ -32,6 +35,7 @@ impl Target {
Self::X86_64Fc => "x86_64",
Self::X86_64Uefi => "x86_64",
Self::Aarch64 => "aarch64",
Self::Aarch64Be => "aarch64_be",
Self::Riscv64 => "riscv64",
}
}
Expand All @@ -42,16 +46,28 @@ impl Target {
Self::X86_64Fc => "x86_64-unknown-none",
Self::X86_64Uefi => "x86_64-unknown-uefi",
Self::Aarch64 => "aarch64-unknown-none-softfloat",
Self::Aarch64Be => "aarch64_be-unknown-none-softfloat",
Self::Riscv64 => "riscv64imac-unknown-none-elf",
}
}

pub fn tier(&self) -> u8 {
match self {
Self::Aarch64Be => 3,
_ => 2,
}
}

pub fn cargo_args(&self) -> &'static [&'static str] {
match self {
Self::X86_64 => &["--target=x86_64-unknown-none"],
Self::X86_64Fc => &["--target=x86_64-unknown-none"],
Self::X86_64Uefi => &["--target=x86_64-unknown-uefi"],
Self::Aarch64 => &["--target=aarch64-unknown-none-softfloat"],
Self::Aarch64Be => &[
"--target=aarch64_be-unknown-none-softfloat",
"-Zbuild-std=core,alloc,panic_abort",
],
Self::Riscv64 => &["--target=riscv64imac-unknown-none-elf"],
}
}
Expand All @@ -67,7 +83,7 @@ impl Target {
"-Crelocation-model=static",
],
Self::X86_64Uefi => &[],
Self::Aarch64 => &["-Clink-arg=-Tsrc/arch/aarch64/link.ld"],
Self::Aarch64 | Self::Aarch64Be => &["-Clink-arg=-Tsrc/arch/aarch64/link.ld"],
Self::Riscv64 => &["-Clink-arg=-Tsrc/arch/riscv64/link.ld"],
}
}
Expand All @@ -92,9 +108,18 @@ impl Target {
Self::X86_64Fc => "hermit-loader-x86_64-fc",
Self::X86_64Uefi => "hermit-loader-x86_64.efi",
Self::Aarch64 => "hermit-loader-aarch64",
Self::Aarch64Be => "hermit-loader-aarch64_be",
Self::Riscv64 => "hermit-loader-riscv64",
}
}

pub fn qemu(&self) -> &'static str {
match self {
Self::X86_64 | Self::X86_64Fc | Self::X86_64Uefi => "x86_64",
Self::Aarch64 | Self::Aarch64Be => "aarch64",
Self::Riscv64 => "riscv64",
}
}
}

impl FromStr for Target {
Expand All @@ -106,6 +131,7 @@ impl FromStr for Target {
"x86_64-fc" => Ok(Self::X86_64Fc),
"x86_64-uefi" => Ok(Self::X86_64Uefi),
"aarch64" => Ok(Self::Aarch64),
"aarch64_be" => Ok(Self::Aarch64Be),
"riscv64" => Ok(Self::Riscv64),
s => Err(anyhow!("Unsupported target: {s}")),
}
Expand Down
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