Initial commit

src/arch/x86_64/linker.ld

@@ -0,0 +1,77 @@
+/* Tell the linker that we want an x86_64 ELF64 output file */
+OUTPUT_FORMAT(elf64-x86-64)
+OUTPUT_ARCH(i386:x86-64)
+
+/* We want the symbol _start to be our entry point */
+ENTRY(_start)
+
+/* Define the program headers we want so the bootloader gives us the right */
+/* MMU permissions; this also allows us to exert more control over the linking */
+/* process. */
+PHDRS
+{
+    headers PT_PHDR PHDRS;
+    text    PT_LOAD FILEHDR PHDRS;
+    rodata  PT_LOAD;
+    data    PT_LOAD;
+    dynamic PT_DYNAMIC;
+}
+
+SECTIONS
+{
+    /* We want to be placed in the topmost 2GiB of the address space, for optimisations */
+    /* and because that is what the Limine spec mandates. */
+    /* Any address in this region will do, but often 0xffffffff80000000 is chosen as */
+    /* that is the beginning of the region. */
+    /* Additionally, leave space for the ELF headers by adding SIZEOF_HEADERS to the */
+    /* base load address. */
+    . = 0xffffffff80000000 + SIZEOF_HEADERS;
+
+    .text : {
+        *(.text .text.*)
+    } :text
+
+    /* Move to the next memory page for .rodata */
+    . = ALIGN(CONSTANT(MAXPAGESIZE));
+
+    .rodata : {
+        *(.rodata .rodata.*)
+    } :rodata
+
+    /* Move to the next memory page for .data */
+    . = ALIGN(CONSTANT(MAXPAGESIZE));
+
+    .data : {
+        *(.data .data.*)
+
+        /* Place the sections that contain the Limine requests as part of the .data */
+        /* output section. */
+        KEEP(*(.requests_start_marker))
+        KEEP(*(.requests))
+        KEEP(*(.requests_end_marker))
+    } :data
+
+    /* Dynamic section for relocations, both in its own PHDR and inside data PHDR. */
+    .dynamic : {
+        *(.dynamic)
+    } :data :dynamic
+
+    /* NOTE: .bss needs to be the last thing mapped to :data, otherwise lots of */
+    /* unnecessary zeros will be written to the binary. */
+    /* If you need, for example, .init_array and .fini_array, those should be placed */
+    /* above this. */
+    .bss : {
+        *(.bss .bss.*)
+        *(COMMON)
+    } :data
+
+    /* Discard .note.* and .eh_frame* since they may cause issues on some hosts. */
+    /* Also discard the program interpreter section since we do not need one. This is */
+    /* more or less equivalent to the --no-dynamic-linker linker flag, except that it */
+    /* works with ld.gold. */
+    /DISCARD/ : {
+        *(.eh_frame*)
+        *(.note .note.*)
+        *(.interp)
+    }
+}

src/arch/x86_64/mod.rs

@@ -0,0 +1 @@
+pub mod port;

src/arch/x86_64/port.rs

@@ -0,0 +1,105 @@
+use core::arch::asm;
+
+#[inline(always)]
+pub unsafe fn read_u8(port: u16) -> u8 {
+    let value: u8;
+    unsafe {
+        asm!(
+            "in al, dx",
+            in("dx") port,
+            out("al") value,
+            options(nomem, nostack, preserves_flags),
+        );
+    }
+    value
+}
+
+#[inline(always)]
+pub unsafe fn read_u8_slice(port: u16, slice: &mut [u8]) {
+    unsafe {
+        asm!(
+            "rep insb",
+            in("dx") port,
+            inout("rdi") slice.as_mut_ptr() => _,
+            inout("rcx") slice.len() => _,
+            options(nostack, preserves_flags),
+        );
+    }
+}
+
+#[inline(always)]
+pub unsafe fn read_u16(port: u16) -> u16 {
+    let value: u16;
+    unsafe {
+        asm!(
+            "in ax, dx",
+            in("dx") port,
+            out("ax") value,
+            options(nomem, nostack, preserves_flags),
+        );
+    }
+    value
+}
+
+#[inline(always)]
+pub unsafe fn read_u32(port: u16) -> u32 {
+    let value: u32;
+    unsafe {
+        asm!(
+            "in eax, dx",
+            in("dx") port,
+            out("eax") value,
+            options(nomem, nostack, preserves_flags),
+        );
+    }
+    value
+}
+
+#[inline(always)]
+pub unsafe fn write_u8(port: u16, value: u8) {
+    unsafe {
+        asm!(
+            "out dx, al",
+            in("dx") port,
+            in("al") value,
+            options(nomem, nostack, preserves_flags),
+        );
+    }
+}
+
+#[inline(always)]
+pub unsafe fn write_u8_slice(port: u16, slice: &[u8]) {
+    unsafe {
+        asm!(
+            "rep outsb",
+            in("dx") port,
+            inout("rsi") slice.as_ptr() => _,
+            inout("rcx") slice.len() => _,
+            options(nostack, preserves_flags),
+        );
+    }
+}
+
+#[inline(always)]
+pub unsafe fn write_u16(port: u16, value: u16) {
+    unsafe {
+        asm!(
+            "out dx, ax",
+            in("dx") port,
+            in("ax") value,
+            options(nomem, nostack, preserves_flags),
+        );
+    }
+}
+
+#[inline(always)]
+pub unsafe fn write_u32(port: u16, value: u32) {
+    unsafe {
+        asm!(
+            "out dx, eax",
+            in("dx") port,
+            in("eax") value,
+            options(nomem, nostack, preserves_flags),
+        );
+    }
+}

src/arch/x86_64/x86_64-unknown-none.json

@@ -0,0 +1,20 @@
+{
+  "arch": "x86_64",
+  "cpu": "x86-64",
+  "data-layout": "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128",
+  "llvm-target": "x86_64-unknown-none",
+  "target-endian": "little",
+  "target-pointer-width": 64,
+  "target-c-int-width": 32,
+  "features": "-mmx,-sse,+soft-float",
+  "rustc-abi": "softfloat",
+  "os": "DawnOS",
+  "linker": "rust-lld",
+  "linker-flavor": "ld.lld",
+  "pre-link-args": {
+    "ld.lld": ["-melf_x86_64", "--script=./src/arch/x86_64/linker.ld"]
+  },
+  "panic-strategy": "abort",
+  "exe-suffix": ".elf",
+  "disable-redzone": true
+}