Initinal commit

.cargo/config

+ [target.mipsel-unknown-none]
+ rustflags = [
+        "-C", "link-arg=-Tlink.ld",
+        # "-C", "link-arg=-nostartfiles",
+        "-C", "relocation-model=static",
+        "-C", "inline-threshold=275",
+        "-C", "lto"
+ ]
+
+[build]
+target = "mipsel-unknown-none"
\ No newline at end of file

.gitignore

+/target
+**/*.rs.bk

Cargo.lock

+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "reverse"
+version = "0.1.0"
+

Cargo.toml

+[package]
+name = "reverse"
+version = "0.1.0"
+authors = ["pln <Per Lindgren>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
+
+[profile.release]
+#opt-level = 'z'     # Optimize for size.
+opt-level = 3       # Aggressive optimization
+debug = true        # keep debug symbols
+lto = true          # Enable Link Time Optimization
+codegen-units = 1   # Reduce number of codegen units to increase optimizations.
+panic = 'abort'     # Abort on panic
\ No newline at end of file

link.ld

+START_ADDR = 0x00000000;
+MEMORY_SIZE = 0x80000000;
+ASSERT(DEFINED(_start), "Cannot find entry point: fn _start() -> !");
+ENTRY(_start);
+
+SECTIONS
+{
+    . = START_ADDR;
+
+    .text :
+    {
+        *(.init)
+        *(.text*)
+    }
+
+    .rodata :
+    {
+        *(.rodata*)
+    }
+
+    _gp = ALIGN(16);
+
+    .data :
+    {
+        *(.data*)
+    }
+
+    _BSS_START = .;
+    .bss :
+    {
+        *(.bss*)
+    }
+    _BSS_END = .;
+
+    .vectors ALIGN(0x1000) :
+    {
+        _VECTOR_START = .;
+        KEEP(*(.tlb_exception))
+        . = _VECTOR_START + 0x180;
+        KEEP(*(.exception))
+    }
+
+    _STACK_END = .;
+    _STACK_START =  START_ADDR + MEMORY_SIZE;
+}
\ No newline at end of file

link.x.in

+START_ADDR = 0x00000000;
+MEMORY_SIZE = 0x80000000;
+ASSERT(DEFINED(_start), "Cannot find entry point: fn _start() -> !");
+ENTRY(_start);
+
+SECTIONS
+{
+    . = START_ADDR;
+
+    .text :
+    {
+        *(.init)
+        *(.text*)
+    }
+
+    .rodata :
+    {
+        *(.rodata*)
+    }
+
+    _gp = ALIGN(16);
+
+    .data :
+    {
+        *(.data*)
+    }
+
+    _BSS_START = .;
+    .bss :
+    {
+        *(.bss*)
+    }
+    _BSS_END = .;
+
+    .vectors ALIGN(0x1000) :
+    {
+        _VECTOR_START = .;
+        KEEP(*(.tlb_exception))
+        . = _VECTOR_START + 0x180;
+        KEEP(*(.exception))
+    }
+
+    _STACK_END = .;
+    _STACK_START =  START_ADDR + MEMORY_SIZE;
+}
\ No newline at end of file

mipsel-unknown-none.json

+{
+    "llvm-target": "mipsel-unknown-none",
+    "arch": "mips",
+    "cpu": "mips32r3",
+    "data-layout": "e-m:m-p:32:32-i8:8:32-i16:16:32-i64:64-n32-S64",
+    "executables": true,
+    "features": "+mips32r3,+soft-float",
+    "linker-flavor": "ld.lld",
+    "linker": "rust-lld",
+    "panic-strategy": "abort",
+    "max-atomic-width": 32,
+    "os": "none",
+    "target-c-int-width": "32",
+    "target-endian": "little",
+    "target-pointer-width": "32"
+}
\ No newline at end of file

objdump_mips.s

+
+target/mipsel-unknown-none/release/reverse:	file format ELF32-mips
+
+
+Disassembly of section .text:
+
+00000000 _start:
+; pub extern "C" fn _start() -> ! {
+       0: f0 ff bd 27                  	addiu	$sp, $sp, -16
+       4: 0c 00 bf af                  	sw	$ra, 12($sp)
+;     rev(&FROM[..], &mut to);
+       8: 00 00 01 3c                  	lui	$1, 0
+       c: 00 00 a6 27                  	addiu	$6, $sp, 0
+      10: 0b 00 05 24                  	addiu	$5, $zero, 11
+      14: 0b 00 07 24                  	addiu	$7, $zero, 11
+;     let mut to: [u8; SIZE] = [0; SIZE];
+      18: 0a 00 a0 ab                  	swl	$zero, 10($sp)
+      1c: 07 00 a0 bb                  	swr	$zero, 7($sp)
+      20: 04 00 a0 af                  	sw	$zero, 4($sp)
+      24: 00 00 a0 af                  	sw	$zero, 0($sp)
+;     rev(&FROM[..], &mut to);
+      28: 19 00 00 0c                  	jal	100 <reverse.a07il72d-cgu.0+0x64>
+      2c: f8 00 24 24                  	addiu	$4, $1, 248
+;     intrinsics::volatile_load(src)
+      30: 0a 00 a1 93                  	lbu	$1, 10($sp)
+      34: 09 00 a1 93                  	lbu	$1, 9($sp)
+      38: 08 00 a1 93                  	lbu	$1, 8($sp)
+      3c: 07 00 a1 93                  	lbu	$1, 7($sp)
+      40: 06 00 a1 93                  	lbu	$1, 6($sp)
+      44: 05 00 a1 93                  	lbu	$1, 5($sp)
+      48: 04 00 a1 93                  	lbu	$1, 4($sp)
+      4c: 03 00 a1 93                  	lbu	$1, 3($sp)
+      50: 02 00 a1 93                  	lbu	$1, 2($sp)
+      54: 01 00 a1 93                  	lbu	$1, 1($sp)
+      58: 00 00 a1 93                  	lbu	$1, 0($sp)
+;     loop {}
+      5c: 17 00 00 08                  	j	92 <reverse.a07il72d-cgu.0+0x5c>
+      60: 00 00 00 00                  	nop
+
+00000064 reverse::rev::h99451ae97e77db4d:
+; }
+      64: 15 00 a0 10                  	beqz	$5, 88 <reverse.a07il72d-cgu.0+0xbc>
+;     if len > 0 {
+      68: 00 00 00 00                  	nop
+      6c: f0 ff bd 27                  	addiu	$sp, $sp, -16
+      70: 0c 00 bf af                  	sw	$ra, 12($sp)
+      74: 08 00 b2 af                  	sw	$18, 8($sp)
+      78: 04 00 b1 af                  	sw	$17, 4($sp)
+      7c: 00 00 b0 af                  	sw	$16, 0($sp)
+;         from_raw_parts(slice.as_ptr().add(self.start), self.end - self.start)
+      80: ff ff b2 24                  	addiu	$18, $5, -1
+      84: 25 88 80 00                  	move	$17, $4
+;         intrinsics::offset(self, count)
+      88: 01 00 84 24                  	addiu	$4, $4, 1
+      8c: 25 80 c0 00                  	move	$16, $6
+;         rev(&from[1..], &mut to[..len - 1]);
+      90: 25 28 40 02                  	move	$5, $18
+      94: 19 00 00 0c                  	jal	100 <reverse.a07il72d-cgu.0+0x64>
+      98: 25 38 40 02                  	move	$7, $18
+;         to[len - 1] = from[0];
+      9c: 21 08 12 02                  	addu	$1, $16, $18
+      a0: 00 00 22 92                  	lbu	$2, 0($17)
+      a4: 00 00 b0 8f                  	lw	$16, 0($sp)
+      a8: 04 00 b1 8f                  	lw	$17, 4($sp)
+      ac: 08 00 b2 8f                  	lw	$18, 8($sp)
+      b0: 0c 00 bf 8f                  	lw	$ra, 12($sp)
+      b4: 00 00 22 a0                  	sb	$2, 0($1)
+      b8: 10 00 bd 27                  	addiu	$sp, $sp, 16
+; }
+      bc: 08 00 e0 03                  	jr	$ra
+      c0: 00 00 00 00                  	nop

src/build.rs

+use std::env;
+use std::fs::{self, File};
+use std::io::Write;
+use std::path::PathBuf;
+
+fn main() {
+    // let target = env::var("TARGET").unwrap();
+    // let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap());
+
+    // has_fpu(&target);
+
+    // if target.starts_with("thumbv") {
+    //     fs::copy(
+    //         format!("bin/{}.a", target),
+    //         out_dir.join("libcortex-m-rt.a"),
+    //     )
+    //     .unwrap();
+    //     println!("cargo:rustc-link-lib=static=cortex-m-rt");
+    // }
+
+    // Put the linker script somewhere the linker can find it
+    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    let link_x = include_bytes!("link.x.in");
+    let mut f = if env::var_os("CARGO_FEATURE_DEVICE").is_some() {
+        let mut f = File::create(out.join("link.x")).unwrap();
+
+        f.write_all(link_x).unwrap();
+
+        // *IMPORTANT*: The weak aliases (i.e. `PROVIDED`) must come *after* `EXTERN(__INTERRUPTS)`.
+        // Otherwise the linker will ignore user defined interrupts and always populate the table
+        // with the weak aliases.
+//         writeln!(
+//             f,
+//             r#"
+// /* Provides weak aliases (cf. PROVIDED) for device specific interrupt handlers */
+// /* This will usually be provided by a device crate generated using svd2rust (see `device.x`) */
+// INCLUDE device.x"#
+//         )
+//         .unwrap();
+//         f
+//     } else {
+//         let mut f = File::create(out.join("link.x")).unwrap();
+//         f.write_all(link_x).unwrap();
+//         f
+//     };
+    }
+//     let max_int_handlers = if target.starts_with("thumbv6m-") {
+//         println!("cargo:rustc-cfg=cortex_m");
+//         println!("cargo:rustc-cfg=armv6m");
+//         32
+//     } else if target.starts_with("thumbv7m-") || target.starts_with("thumbv7em-") {
+//         println!("cargo:rustc-cfg=cortex_m");
+//         println!("cargo:rustc-cfg=armv7m");
+//         240
+//     } else if target.starts_with("thumbv8m") {
+//         println!("cargo:rustc-cfg=cortex_m");
+//         println!("cargo:rustc-cfg=armv8m");
+//         240
+//     } else {
+//         // Non ARM target. We assume you're just testing the syntax.
+//         // This value seems as soon as any
+//         240
+//     };
+
+//     // checking the size of the interrupts portion of the vector table is sub-architecture dependent
+//     writeln!(
+//         f,
+//         r#"
+// ASSERT(SIZEOF(.vector_table) <= 0x{:x}, "
+// There can't be more than {1} interrupt handlers. This may be a bug in
+// your device crate, or you may have registered more than {1} interrupt
+// handlers.");
+// "#,
+//         max_int_handlers * 4 + 0x40,
+//         max_int_handlers
+//     )
+//     .unwrap();
+
+    println!("cargo:rustc-link-search={}", out.display());
+
+    println!("cargo:rerun-if-changed=build.rs");
+    println!("cargo:rerun-if-changed=link.x.in");
+}
+
+// fn has_fpu(target: &str) {
+//     if target.ends_with("eabihf") {
+//         println!("cargo:rustc-cfg=has_fpu");
+//     }
+// }

src/main.rs

+// #![feature(const_generics)]
+// fn rev<const X: usize>(from: &[u8; X], to: &mut [u8; X]) {
+//     if from.len() > 0 {}
+// }
+#![feature(lang_items)]
+#![no_std]
+#![no_main]
+
+// use panic_abort;
+// use libc;
+
+fn rev(from: &[u8], to: &mut [u8]) {
+    let len = from.len();
+    if len > 0 {
+        rev(&from[1..], &mut to[..len - 1]);
+        to[len - 1] = from[0];
+    }
+}
+
+const FROM: &[u8] = b"Hello Word!";
+const SIZE: usize = FROM.len();
+
+#[no_mangle]
+pub extern "C" fn main() {
+    let mut to: [u8; SIZE] = [0; SIZE];
+    rev(&FROM[..], &mut to);
+    unsafe {
+        core::ptr::read_volatile(&to);
+    }
+
+    // println!("from : {:?}", std::str::from_utf8(FROM).unwrap());
+    // println!("to   : {:?}", std::str::from_utf8(&to).unwrap());
+}
+
+#[panic_handler]
+fn my_panic(_info: &core::panic::PanicInfo) -> ! {
+    loop {}
+}
+
+// The reset vector, a pointer into the reset handler
+#[link_section = ".init"]
+#[no_mangle]
+pub extern "C" fn _start() -> ! {
+    main();
+    loop {}
+}
+
+#[lang = "eh_personality"]
+extern "C" fn eh_personality() {}
+// #[lang = "panic_fmt"]
+// extern "C" fn panic_fmt() -> ! {
+//     loop {}
+// }