initial

.cargo/config.toml

@@ -0,0 +1,9 @@
+[build]
+target = "riscv64gc-unknown-none-elf"
+
+[target.riscv64gc-unknown-none-elf]
+rustflags = ["-C", "link-arg=-Tsrc/ld/kernel.ld"]
+runner = "./scripts/start.sh"
+
+[term]
+verbose = true

.gitignore

@@ -1,2 +1,9 @@
 /target
 /build
+
+
+# Added by cargo
+#
+# already existing elements were commented out
+
+#/target

Cargo.lock

@@ -3,5 +3,5 @@
 version = 3
 
 [[package]]
-name = "kernel"
+name = "eos0"
 version = "0.1.0"

Cargo.toml

@@ -1,5 +1,6 @@
-workspace.members = ["kernel"]
+[package]
-workspace.resolver = "2"
+name = "eos0"
+version = "0.1.0"
+edition = "2021"
 
-profile.dev.panic = "abort"
+[dependencies]
-profile.release.panic = "abort"

Makefile

@@ -0,0 +1,8 @@
+KERNEL = target/riscv64gc-unknown-none-elf/debug/xv6-riscv-rust
+SOURCES := $(shell find -name "*.rs")
+
+$(KERNEL): $(SOURCES)
+	cargo build
+
+fs.img: mkfs/mkfs README.md $(UPROGS)
+	mkfs/mkfs fs.img README.md $(UPROGS)

README.md

@@ -1,9 +0,0 @@
-# EOS0
-
-This is mainly a port of MIT's xv6 operating system, for educational purposes.
-
-You can consider the "e" in EOS to be either educational or experimental.
-
-## References
-
-- https://lowenware.com/blog/aarch64-bare-metal-program-in-rust/

aarch64-qemu.ld

@@ -1,14 +0,0 @@
-ENTRY(_start)
-SECTIONS
-{
-    . = 0x40080000;
-    .text.boot : { *(.text.boot) }
-    .text : { *(.text) }
-    .data : { *(.data) }
-    .rodata : { *(.rodata) }
-    .bss : { *(.bss) }
-
-    . = ALIGN(8);
-    . = . + 0x4000;
-    LD_STACK_PTR = .;
-}

aarch64-unknown-none.json

@@ -1,23 +0,0 @@
-{
-	"arch": "aarch64",
-	"crt-objects-fallback": "false",
-	"data-layout": "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128",
-	"disable-redzone": true,
-	"features": "-align,-neon",
-	"linker": "rust-lld",
-	"linker-flavor": "gnu-lld",
-	"llvm-target": "aarch64-unknown-none",
-	"max-atomic-width": 128,
-	"panic-strategy": "abort",
-	"pre-link-args": {
-		"gnu": ["--fix-cortex-a53-843419"],
-		"gnu-lld": ["--fix-cortex-a53-843419", "-Taarch64-qemu.ld"],
-		"ld.lld": ["-Taarch64-qemu.ld"]
-	},
-	"relocation-model": "static",
-	"stack-probes": {
-		"kind": "inline"
-	},
-	"supported-sanitizers": ["kcfi", "kernel-address"],
-	"target-pointer-width": "64"
-}

debug.sh

@@ -1,5 +0,0 @@
-# Run run.sh before this!
-set -euo pipefail
-exec rust-lldb \
-  -s lldb-init \
-  target/aarch64-unknown-none/debug/kernel

kernel/Cargo.toml

@@ -1,9 +0,0 @@
-[package]
-name = "kernel"
-version = "0.1.0"
-edition = "2021"
-
-# [lib]
-# crate-type = ["staticlib"]
-
-[dependencies]

kernel/src/console.rs

@@ -1,27 +0,0 @@
-use core::fmt::{self, Write};
-
-use crate::{spinlock::SpinLock, uart::UART};
-
-/// A wrapper around the console
-pub struct Console {
-  lock: SpinLock,
-  uart: UART,
-}
-
-impl Console {
-  pub fn init() -> Self {
-    let lock = SpinLock::init("console");
-    let uart = UART::init();
-    Console { lock, uart }
-  }
-}
-
-impl Write for Console {
-  fn write_str(&mut self, s: &str) -> fmt::Result {
-    // TODO: Lock
-
-    Ok(())
-
-    // TODO: Release lock
-  }
-}

kernel/src/io.rs

@@ -1 +0,0 @@
-

kernel/src/macros.rs

@@ -1 +0,0 @@
-

kernel/src/main.rs

@@ -1,34 +0,0 @@
-#![no_std]
-#![no_main]
-
-use core::fmt::Write;
-use core::{arch::global_asm, ptr};
-
-use crate::console::Console;
-use crate::memory_layout::UART0;
-
-#[macro_use]
-mod macros;
-
-mod console;
-mod io;
-mod memory_layout;
-mod panic;
-mod spinlock;
-mod uart;
-
-// global_asm!(include_str!("start.s"));
-global_asm!(include_str!("riscv64gc/start.s"));
-
-#[no_mangle]
-pub extern "C" fn main() {
-  let mut console = Console::init();
-  // let _ = writeln!(console, "eos0 is booting...");
-
-  let out_str = b"AArch64 Bare Metal";
-  for byte in out_str {
-    unsafe {
-      ptr::write_volatile(UART0, *byte);
-    }
-  }
-}

kernel/src/memory_layout.rs

@@ -1 +0,0 @@
-pub const UART0: *mut u8 = 0x0900_0000 as *mut u8;

kernel/src/panic.rs

@@ -1,7 +0,0 @@
-use core::panic::PanicInfo;
-
-#[cfg(not(test))]
-#[panic_handler]
-fn on_panic(_info: &PanicInfo) -> ! {
-  loop {}
-}

kernel/src/riscv64gc/start.s

@@ -1,15 +0,0 @@
-.section .text
-
-.global _entry
-
-_entry:
-    la sp, stack0
-    li a0, 1024*4
-    csrr a1, mhartid
-    addi a1, a1, 1
-    mul a0, a0, a1
-    add sp, sp, a0
-    call main
-
-spin:
-    j spin

kernel/src/spinlock.rs

@@ -1,18 +0,0 @@
-pub struct SpinLock {
-  locked: bool,
-
-  /// The name of the lock, for debugging
-  name: [u8; 32],
-}
-
-impl SpinLock {
-  pub fn init(name: &'static str) -> Self {
-    let mut this_name = [0; 32];
-    this_name.copy_from_slice(&name.as_bytes()[..32.min(name.len())]);
-
-    SpinLock {
-      locked: false,
-      name: this_name,
-    }
-  }
-}

kernel/src/start.s

@@ -1,15 +0,0 @@
-.globl _start
-.extern LD_STACK_PTR
-
-.section ".text.boot"
-
-_start:
-    ldr     x30, =LD_STACK_PTR
-    mov     sp, x30
-    bl      main
-
-.equ PSCI_SYSTEM_OFF, 0x84000008
-.globl system_off
-system_off:
-    ldr     x0, =PSCI_SYSTEM_OFF
-    hvc     #0

kernel/src/uart.rs

@@ -1,40 +0,0 @@
-//! UART (Universal Asynchronous Receiver-Transmitter)
-
-use crate::memory_layout::UART0;
-
-/// The UART Interface
-pub struct UART {}
-
-impl UART {
-  /// Most of this is just a port from xv6 right now, I have no idea why any of this works
-  pub fn init() -> Self {
-    unsafe {
-      UART::write_register(WriteRegister::IER, 0x00);
-    }
-    UART {}
-  }
-
-  #[inline]
-  pub unsafe fn write_register(reg: WriteRegister, val: u8) {
-    *reg.as_mut_ptr() = val;
-  }
-
-  pub unsafe fn put_char(&self) {}
-}
-
-/// <http://byterunner.com/16550.html>
-pub enum ReadRegister {}
-
-#[derive(Copy, Clone)]
-pub enum WriteRegister {
-  IER = 1,
-}
-
-impl WriteRegister {
-  pub fn as_mut_ptr(&self) -> *mut u8 {
-    unsafe { UART0.offset(*self as isize) }
-  }
-}
-
-#[inline]
-fn read_register() {}

lldb-init

@@ -1,2 +0,0 @@
-target create target/aarch64-unknown-none/debug/kernel
-gdb-remote 1234

riscv64gc-unknown-none-elf.json

@@ -1,22 +0,0 @@
-{
-	"arch": "riscv64",
-	"code-model": "medium",
-	"cpu": "generic-rv64",
-	"crt-objects-fallback": "false",
-	"data-layout": "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128",
-	"eh-frame-header": false,
-	"emit-debug-gdb-scripts": true,
-	"features": "+m,+a,+f,+d,+c",
-	"linker": "rust-lld",
-	"linker-flavor": "gnu-lld",
-	"llvm-abiname": "lp64d",
-	"llvm-target": "riscv64",
-	"max-atomic-width": 64,
-	"panic-strategy": "abort",
-	"relocation-model": "static",
-	"pre-link-args": {
-		"gnu-lld": ["-Taarch64-qemu.ld"]
-	},
-	"supported-sanitizers": ["kernel-address"],
-	"target-pointer-width": "64"
-}

run.sh

@@ -1,16 +0,0 @@
-set -euo pipefail
-cargo xbuild --target=aarch64-unknown-none.json
-
-DEBUG=
-DEBUG="-s -S -d exec"
-
-printf "Running with qemu...\n"
-set -x
-exec qemu-system-aarch64 \
-  -machine virt \
-  $DEBUG \
-  -m 1024M \
-  -cpu cortex-a53 \
-  -no-reboot \
-  -nographic \
-  -kernel target/aarch64-unknown-none/debug/kernel

rust-toolchain

@@ -1 +0,0 @@
-nightly

rustfmt.toml

@@ -1,2 +0,0 @@
-tab_spaces = 2
-max_width = 80

scripts/start.sh

@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+
+KERNEL=$1
+shift
+
+qemu-system-riscv64 \
+    -nographic \
+    -machine virt \
+    -bios none \
+    -m 3G \
+    -smp 3 \
+    # -drive file=fs.img,if=none,format=raw,id=x0 \
+    -device virtio-blk-device,drive=x0,bus=virtio-mmio-bus.0 \
+    -kernel "$KERNEL"

src/ld/kernel.ld

@@ -0,0 +1,12 @@
+OUTPUT_ARCH("riscv")
+ENTRY(_entry)
+
+SECTIONS {
+    /*
+    It seems that QEMU jumps to 0x8000000 after setting up memory, so we want
+    our kernel code to begin here.
+
+    TODO: Is there an authoritative source that says that this is the address?
+    */
+    . = 0x8000000;
+}

src/main.rs

@@ -0,0 +1,25 @@
+#![no_std]
+#![no_main]
+
+use core::panic::PanicInfo;
+
+#[panic_handler]
+fn panic_handler(_: &PanicInfo) -> ! {
+    loop {}
+}
+
+static HELLO: &[u8] = b"Hello World!";
+
+#[no_mangle]
+pub extern "C" fn _start() -> ! {
+    let vga_buffer = 0xb8000 as *mut u8;
+
+    for (i, &byte) in HELLO.iter().enumerate() {
+        unsafe {
+            *vga_buffer.offset(i as isize * 2) = byte;
+            *vga_buffer.offset(i as isize * 2 + 1) = 0xb;
+        }
+    }
+
+    loop {}
+}