Merge pull request #164 from nix-community/rust-2024

add riscv64 port

Author: Mic92

flake.nix

@@ -11,6 +11,7 @@
         "i686-linux"
         "x86_64-linux"
         "aarch64-linux"
+        "riscv64-linux"
       ];
       lib = nixpkgs.lib;
       forAllSystems =
@@ -30,6 +31,10 @@
           nix-ld = pkgs.callPackage ./package.nix { };
           nolibc = pkgs.callPackage ./vendor/nolibc.nix { };
           default = self.packages.${system}.nix-ld;
+
+          # Cross-compiled package for riscv64 (only available on x86_64-linux)
+        } // lib.optionalAttrs (system == "x86_64-linux") {
+          nix-ld-riscv64 = pkgs.pkgsCross.riscv64.callPackage ./package.nix { };
         }
       );
 
@@ -54,7 +59,7 @@
       );
 
       devShells = forAllSystems (
-        { pkgs, ... }:
+        { pkgs, system, ... }:
         {
           nix-ld = pkgs.mkShell {
             nativeBuildInputs = [
@@ -64,6 +69,7 @@
               pkgs.cargo-bloat
               pkgs.cargo-nextest
               pkgs.just
+
             ];
 
             hardeningDisable = [ "stackprotector" ];
@@ -73,7 +79,20 @@
             NIX_LD = pkgs.stdenv.cc.bintools.dynamicLinker;
 
             RUSTC_BOOTSTRAP = "1";
+
+            shellHook = ''
+              echo "nix-ld development environment"
+            '' + lib.optionalString (system == "x86_64-linux") ''
+              echo "Available cross-compilation shell:"
+              echo "  nix develop .#cross-riscv64  - Cross compile to riscv64"
+            '';
           };
+
+          # Default cross shell for current system
+          default = self.devShells.${system}.nix-ld;
+        } // lib.optionalAttrs (system == "x86_64-linux") {
+          # Cross compilation shell for riscv64 (only available on x86_64-linux)
+          cross-riscv64 = pkgs.pkgsCross.riscv64.callPackage ./riscv64-shell.nix { };
         }
       );
     }

riscv64-shell.nix

@@ -0,0 +1,43 @@
+{ mkShell
+, rustc
+, cargo
+, cargo-watch
+, cargo-bloat
+, cargo-nextest
+, just
+, stdenv
+, qemu
+}:
+
+mkShell {
+  nativeBuildInputs = [
+    rustc
+    cargo
+    cargo-watch
+    cargo-bloat
+    cargo-nextest
+    just
+    qemu
+  ];
+
+  hardeningDisable = [ "stackprotector" ];
+
+  RUSTC_BOOTSTRAP = "1";
+
+  # Cross compilation environment
+  CARGO_TARGET_RISCV64GC_UNKNOWN_LINUX_GNU_LINKER = "${stdenv.cc}/bin/${stdenv.cc.targetPrefix}cc";
+  CARGO_TARGET_RISCV64GC_UNKNOWN_LINUX_GNU_RUNNER = "qemu-riscv64 -L /";
+  CC_riscv64gc_unknown_linux_gnu = "${stdenv.cc}/bin/${stdenv.cc.targetPrefix}cc";
+  NIX_LD_TEST_TARGET = "riscv64gc-unknown-linux-gnu";
+  NIX_LD = "${stdenv.cc.libc}/lib/ld-linux-riscv64-lp64d.so.1";
+  TARGET_CC = "${stdenv.cc}/bin/${stdenv.cc.targetPrefix}cc";
+
+  shellHook = ''
+    echo "RISC-V 64-bit cross-compilation environment"
+    echo "Target: riscv64gc-unknown-linux-gnu"
+    echo "Cross compiler: ${stdenv.cc}/bin/${stdenv.cc.targetPrefix}cc"
+    echo "Usage:"
+    echo "  cargo build --target riscv64gc-unknown-linux-gnu"
+    echo "  cargo test --target riscv64gc-unknown-linux-gnu"
+  '';
+}

src/arch.rs

@@ -26,6 +26,8 @@ pub const EM_SELF: u16 = {
     const VALUE: u16 = EM_386;
     #[cfg(target_arch = "aarch64")]
     const VALUE: u16 = EM_AARCH64;
+    #[cfg(target_arch = "riscv64")]
+    const VALUE: u16 = EM_RISCV;
     VALUE
 };
 
@@ -37,6 +39,8 @@ pub const R_RELATIVE: u32 = {
     const VALUE: u32 = R_386_RELATIVE;
     #[cfg(target_arch = "aarch64")]
     const VALUE: u32 = R_AARCH64_RELATIVE;
+    #[cfg(target_arch = "riscv64")]
+    const VALUE: u32 = R_RISCV_RELATIVE;
     VALUE
 };
 
@@ -49,6 +53,8 @@ pub const NIX_SYSTEM: &str = match option_env!("NIX_SYSTEM") {
         const VALUE: &str = "i686_linux";
         #[cfg(target_arch = "aarch64")]
         const VALUE: &str = "aarch64_linux";
+        #[cfg(target_arch = "riscv64")]
+        const VALUE: &str = "riscv64_linux";
         VALUE
     }
 };
@@ -70,6 +76,8 @@ macro_rules! main_relocate_stack {
         core::arch::asm!("mov esp, {}; call {}", in(reg) $sp, sym $func, options(noreturn));
         #[cfg(target_arch = "aarch64")]
         core::arch::asm!("mov sp, {}; bl {}", in(reg) $sp, sym $func, options(noreturn));
+        #[cfg(target_arch = "riscv64")]
+        core::arch::asm!("mv sp, {}; call {}", in(reg) $sp, sym $func, options(noreturn));
     };
 }
 pub(crate) use main_relocate_stack;
@@ -82,6 +90,8 @@ macro_rules! elf_jmp {
         core::arch::asm!("mov esp, {}; jmp {}", in(reg) $sp, in(reg) $target, options(noreturn));
         #[cfg(target_arch = "aarch64")]
         core::arch::asm!("mov sp, {}; br {}", in(reg) $sp, in(reg) $target, options(noreturn));
+        #[cfg(target_arch = "riscv64")]
+        core::arch::asm!("mv sp, {}; jr {}", in(reg) $sp, in(reg) $target, options(noreturn));
     };
 }
 pub(crate) use elf_jmp;
@@ -131,6 +141,9 @@ pub const ENTRY_TRAMPOLINE: Option<unsafe extern "C" fn() -> !> = None;
 #[cfg(target_arch = "x86_64")]
 pub const ENTRY_TRAMPOLINE: Option<unsafe extern "C" fn() -> !> = Some(entry_trampoline);
 
+#[cfg(target_arch = "riscv64")]
+pub const ENTRY_TRAMPOLINE: Option<unsafe extern "C" fn() -> !> = Some(entry_trampoline);
+
 #[cfg(target_arch = "x86_64")]
 #[naked]
 unsafe extern "C" fn entry_trampoline() -> ! {
@@ -173,13 +186,36 @@ unsafe extern "C" fn entry_trampoline() -> ! {
     }
 }
 
+#[cfg(target_arch = "riscv64")]
+#[naked]
+unsafe extern "C" fn entry_trampoline() -> ! {
+    unsafe {
+        core::arch::naked_asm!(
+            "1:",
+            "auipc t0, %pcrel_hi({context})",
+            "addi t0, t0, %pcrel_lo(1b)",
+            "ld t1, {env_entry_off}(t0)", // .env_entry
+            "beqz t1, 2f",
+            "ld t2, {env_string_off}(t0)", // .env_string
+            "sd t2, 0(t1)",
+            "2:",
+            "ld t0, 0(t0)",
+            "jr t0",
+            context = sym TRAMPOLINE_CONTEXT,
+            env_entry_off = const TrampolineContext::ENV_ENTRY_OFFSET,
+            env_string_off = const TrampolineContext::ENV_STRING_OFFSET,
+        )
+    }
+}
+
 // !!!!
 // After adding a trampoline, remember to enable test_ld_path_restore for
 // the target_arch in tests/tests.rs as well
 // !!!!
 #[cfg(all(
     feature = "entry_trampoline",
     not(target_arch = "x86_64"),
-    not(target_arch = "aarch64")
+    not(target_arch = "aarch64"),
+    not(target_arch = "riscv64")
 ))]
 pub const ENTRY_TRAMPOLINE: Option<unsafe extern "C" fn() -> !> = None;

tests/tests.rs

@@ -84,7 +84,11 @@ fn test_dlopen(libtest: &str) {
 /// Check that LD_LIBRARY_PATH is restored.
 #[cfg(all(
     feature = "entry_trampoline",
-    any(target_arch = "x86_64", target_arch = "aarch64")
+    any(
+        target_arch = "x86_64",
+        target_arch = "aarch64",
+        target_arch = "riscv64"
+    )
 ))]
 #[rstest]
 fn test_ld_path_restore(libtest: &str, _dt_needed_bin: &Path) {