init

.cargo/config.toml

@@ -0,0 +1,2 @@
+[build]
+target = "riscv64imac-unknown-none-elf"

.gitignore

@@ -0,0 +1 @@
+/target

Cargo.lock

@@ -0,0 +1,91 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "bit_field"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc827186963e592360843fb5ba4b973e145841266c1357f7180c43526f2e5b61"
+
+[[package]]
+name = "bitflags"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
+[[package]]
+name = "log"
+version = "0.4.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5e6163cb8c49088c2c36f57875e58ccd8c87c7427f7fbd50ea6710b2f3f2e8f"
+
+[[package]]
+name = "raw-cpuid"
+version = "10.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6c297679cb867470fa8c9f67dbba74a78d78e3e98d7cf2b08d6d71540f797332"
+dependencies = [
+ "bitflags",
+]
+
+[[package]]
+name = "rustversion"
+version = "1.0.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7ffc183a10b4478d04cbbbfc96d0873219d962dd5accaff2ffbd4ceb7df837f4"
+
+[[package]]
+name = "sbi-rt"
+version = "0.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8c113c53291db8ac141e01f43224ed488b8d6001ab66737b82e04695a43a42b7"
+dependencies = [
+ "sbi-spec",
+]
+
+[[package]]
+name = "sbi-spec"
+version = "0.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d4027cf9bb591a9fd0fc0e283be6165c5abe96cb73e9f0e24738c227f425377"
+dependencies = [
+ "static_assertions",
+]
+
+[[package]]
+name = "static_assertions"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a2eb9349b6444b326872e140eb1cf5e7c522154d69e7a0ffb0fb81c06b37543f"
+
+[[package]]
+name = "tiny_os"
+version = "0.1.0"
+dependencies = [
+ "log",
+ "sbi-rt",
+ "uart_16550",
+]
+
+[[package]]
+name = "uart_16550"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6dc00444796f6c71f47c85397a35e9c4dbf9901902ac02386940d178e2b78687"
+dependencies = [
+ "bitflags",
+ "rustversion",
+ "x86",
+]
+
+[[package]]
+name = "x86"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2781db97787217ad2a2845c396a5efe286f87467a5810836db6d74926e94a385"
+dependencies = [
+ "bit_field",
+ "bitflags",
+ "raw-cpuid",
+]

Cargo.toml

@@ -0,0 +1,26 @@
+[package]
+name = "tiny_os"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[features]
+default = ["arch_riscv64", "board_virt"]
+arch_riscv64 = []
+arch_arm = []
+arch_x86 = []
+board_default = []
+board_virt = []
+board_thead = []
+
+[profile.dev]
+panic = "abort"
+
+[profile.release]
+panic = "abort"
+
+[dependencies]
+sbi-rt = { version = "0.0.2", features = ["legacy"] }
+uart_16550 = "0.3"
+log = "0.4"

build.rs

@@ -0,0 +1,23 @@
+fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
+
+    struct TargetConfiguration {
+        target: &'static str,
+        lds: &'static str,
+    }
+
+    const TARGET_CONFIGURATIONS: &[TargetConfiguration] = &[TargetConfiguration {
+        target: "riscv64",
+        lds: "src/arch/riscv/boot/linker64.ld",
+    }];
+
+    let target = std::env::var("TARGET").unwrap();
+    for cfg in TARGET_CONFIGURATIONS {
+        if target.starts_with(cfg.target) {
+            println!("cargo:rustc-link-arg=-T{}", cfg.lds);
+            return;
+        }
+    }
+
+    panic!("Unsupported target: {}", target);
+}

rust-toolchain.toml

@@ -0,0 +1,2 @@
+[toolchain]
+channel = "nightly"

src/arch/io.rs

@@ -0,0 +1,72 @@
+use core::fmt::Write;
+
+pub struct RawConsole;
+
+pub trait Printer: Write {
+    fn put_char(c: char);
+
+    #[inline]
+    fn put_str(s: &str) {
+        for c in s.chars() {
+            Self::put_char(c);
+        }
+    }
+
+    #[inline]
+    fn put_line(s: &str) {
+        Self::put_str(s);
+        Self::put_char('\n');
+    }
+
+    fn put_num(mut num: usize) {
+        if num == 0 {
+            Self::put_char('0');
+            return;
+        }
+
+        let digits = "0123456789".as_bytes();
+        let mut buf = [0u8; 10];
+        let mut i = 0;
+
+        while num != 0 {
+            buf[i] = digits[num % 10];
+            num /= 10;
+            i += 1;
+        }
+
+        buf[..i]
+            .iter()
+            .rev()
+            .for_each(|c| Self::put_char(*c as char));
+    }
+
+    fn put_hex(mut num: usize) {
+        if num == 0 {
+            Self::put_str("0x0");
+            return;
+        }
+
+        let alphabet = "0123456789abcdef".as_bytes();
+        let mut buf = [0u8; 8];
+        let mut i = 0;
+
+        while num != 0 {
+            buf[i] = alphabet[num % 16];
+            num /= 16;
+            i += 1;
+        }
+
+        Self::put_str("0x");
+        buf[..i]
+            .iter()
+            .rev()
+            .for_each(|c| Self::put_char(*c as char));
+    }
+}
+
+impl Write for RawConsole {
+    fn write_str(&mut self, s: &str) -> core::fmt::Result {
+        Self::put_str(s);
+        Ok(())
+    }
+}

src/arch/lowlevel.rs

@@ -0,0 +1,18 @@
+pub struct Hardware;
+
+pub trait LowLevel {
+    fn halt() {}
+
+    fn shutdown(_failure: bool) -> ! {
+        Self::halt();
+
+        #[allow(clippy::empty_loop)]
+        loop {}
+    }
+
+    fn reset(_failure: bool) -> ! {
+        panic!("Reset is not implemented for this architecture");
+    }
+
+    fn disable_interrupt() {}
+}

src/arch/mod.rs

@@ -0,0 +1,10 @@
+// Basic IO
+pub mod io;
+
+// Low Level
+pub mod lowlevel;
+
+// Arch Level
+#[cfg(feature = "arch_riscv64")]
+#[path = "riscv/mod.rs"]
+mod riscv;

src/arch/riscv/board/virt/mod.rs

@@ -0,0 +1,3 @@
+pub const UART0_BASE: usize = 0x1000_0000;
+
+pub mod printer;

src/arch/riscv/board/virt/printer.rs

@@ -0,0 +1,17 @@
+use crate::arch::io::{Printer, RawConsole};
+
+impl Printer for RawConsole {
+    #[inline]
+    fn put_char(c: char) {
+        let uart = super::UART0_BASE as *mut char;
+        unsafe { uart.write_volatile(c) }
+    }
+
+    #[inline]
+    fn put_str(s: &str) {
+        let uart = super::UART0_BASE as *mut char;
+        for c in s.chars() {
+            unsafe { uart.write_volatile(c) }
+        }
+    }
+}

src/arch/riscv/boot/linker64.ld

@@ -0,0 +1,52 @@
+OUTPUT_ARCH(riscv)
+ENTRY(_start)
+
+BASE_ADDRESS = 0x80200000;
+
+MEMORY {
+    DRAM : ORIGIN = BASE_ADDRESS, LENGTH = 16M
+}
+
+SECTIONS {
+    . = BASE_ADDRESS;
+
+    .text : {
+        __text_start = .;
+        *(.text.entry)
+        *(.text .text.*)
+        __text_end = .;
+    } > DRAM
+
+    .rodata : {
+        . = ALIGN(8);
+        __rodata_start = .;
+        *(.rodata .rodata.*)
+        *(.srodata .srodata.*)
+        __rodata_end = .;
+    } > DRAM
+
+    .data : {
+        . = ALIGN(8);
+        __data_start = .;
+        *(.data .data.*)
+        *(.sdata .sdata.*)
+        __data_end = .;
+    } > DRAM
+
+    .stack : {
+        . = ALIGN(8);
+        *(.boot_stack)
+    } > DRAM
+
+    .bss : {
+        . = ALIGN(8);
+        __bss_start = .;
+        *(.bss .bss.*)
+        *(.sbss .sbss.*)
+        __bss_end = .;
+    } > DRAM
+
+    /DISCARD/ : {
+        *(.eh_frame)
+    }
+}

src/arch/riscv/entry.rs

@@ -0,0 +1,43 @@
+#[naked]
+#[no_mangle]
+#[link_section = ".text.entry"]
+unsafe extern "C" fn _start(hart_id: usize, device_tree_addr: usize) -> ! {
+    // simplest starter
+    // no stack here
+
+    const STACK_SIZE: usize = 4096 * 16;
+    #[link_section = ".boot_stack"]
+    static mut STACK: [u8; STACK_SIZE] = [0u8; STACK_SIZE];
+
+    core::arch::asm!(
+        "la sp,  {stack} + {stack_size}",
+        "j  {main}",
+        stack_size = const STACK_SIZE,
+        stack      = sym STACK,
+        main       = sym pre_main,
+        options(noreturn),
+    )
+}
+
+extern "C" fn pre_main(hart_id: usize, device_tree_addr: usize) -> ! {
+    unsafe { zero_bss() }
+
+    // TODO: initialize page table
+
+    crate::entry::rust_main(hart_id, device_tree_addr);
+}
+
+extern "C" {
+    static mut __bss_start: u8;
+    static mut __bss_end: u8;
+}
+
+unsafe fn zero_bss() {
+    let mut cur = &mut __bss_start as *mut u8;
+    let end = &mut __bss_end as *mut u8;
+
+    while cur < end {
+        cur.write_volatile(0);
+        cur = cur.add(1);
+    }
+}

src/arch/riscv/io.rs

@@ -0,0 +1,10 @@
+#[allow(unused_imports)]
+use crate::arch::io::{Printer, RawConsole};
+
+#[cfg(feature = "board_default")]
+impl Printer for RawConsole {
+    fn put_char(c: char) {
+        #[allow(deprecated)]
+        sbi_rt::legacy::console_putchar(c as usize);
+    }
+}

src/arch/riscv/lowlevel.rs

@@ -0,0 +1,37 @@
+use crate::arch::lowlevel::{Hardware, LowLevel};
+use log::error;
+
+impl LowLevel for Hardware {
+    #[inline]
+    fn halt() {
+        unsafe { core::arch::asm!("wfi") }
+    }
+
+    #[inline]
+    fn shutdown(failure: bool) -> ! {
+        Self::disable_interrupt();
+
+        if failure {
+            sbi_rt::system_reset(sbi_rt::Shutdown, sbi_rt::SystemFailure);
+        } else {
+            sbi_rt::system_reset(sbi_rt::Shutdown, sbi_rt::NoReason);
+        }
+
+        loop {
+            // in case system_reset failed
+            Self::halt()
+        }
+    }
+
+    #[inline]
+    fn reset(failure: bool) -> ! {
+        if failure {
+            sbi_rt::system_reset(sbi_rt::ColdReboot, sbi_rt::SystemFailure);
+        } else {
+            sbi_rt::system_reset(sbi_rt::WarmReboot, sbi_rt::NoReason);
+        }
+
+        error!("[riscv/lowlevel] system_reset failed, shutdown instead");
+        Self::shutdown(true);
+    }
+}

src/arch/riscv/mod.rs

@@ -0,0 +1,7 @@
+#[cfg(feature = "board_virt")]
+#[path = "board/virt/mod.rs"]
+mod board;
+
+pub mod entry;
+pub mod io;
+pub mod lowlevel;

src/entry.rs

@@ -0,0 +1,30 @@
+use crate::arch::lowlevel::{Hardware, LowLevel};
+use log::{error, info};
+
+pub extern "C" fn rust_main(hart_id: usize, device_tree_addr: usize) -> ! {
+    crate::logging::init();
+
+    info!("[rust_main] Kernel Started");
+
+    info!("Hello World!");
+    info!("hart_id = {}", hart_id);
+    info!("device_tree_addr = {:#x}", device_tree_addr);
+
+    // TODO: setup and start scheduler
+
+    error!("[rust_main] Should not reach here! Maybe scheduler is not working?");
+    Hardware::shutdown(true);
+}
+
+pub fn print_hello() {
+    const SERIAL_PORT_BASE_ADDRESS: usize = 0x1000_0000;
+    const HELLO: &[u8] = b"Hello World!\n";
+
+    use uart_16550::MmioSerialPort;
+    let mut serial_port = unsafe { MmioSerialPort::new(SERIAL_PORT_BASE_ADDRESS) };
+    serial_port.init();
+
+    for &byte in HELLO {
+        serial_port.send(byte);
+    }
+}

src/lang.rs

@@ -0,0 +1,21 @@
+use crate::arch::lowlevel::{Hardware, LowLevel};
+use core::panic::PanicInfo;
+use log::error;
+
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    error!("[lang] Kernel panic!");
+
+    if let Some(location) = info.location() {
+        error!(
+            "[lang] Panicked: [{}:{}] {}",
+            location.file(),
+            location.line(),
+            info.message().unwrap(),
+        );
+    } else {
+        error!("[lang] Panicked: {}", info.message().unwrap());
+    }
+
+    Hardware::shutdown(true);
+}

src/lib.rs

@@ -0,0 +1,17 @@
+#![no_std]
+#![feature(asm_const)]
+#![feature(naked_functions)]
+#![feature(panic_info_message)]
+#![feature(fmt_internals)]
+
+// arch
+pub mod arch;
+
+// rust language runtime
+pub mod lang;
+
+// entrypoint
+pub mod entry;
+
+// logging
+pub mod logging;

src/logging.rs

@@ -0,0 +1,31 @@
+use crate::arch::io::RawConsole;
+use core::fmt::Write;
+use log::{self, LevelFilter, Log, Metadata, Record};
+
+struct SimpleLogger;
+
+impl Log for SimpleLogger {
+    fn enabled(&self, _metadata: &Metadata) -> bool {
+        true
+    }
+
+    fn log(&self, record: &Record) {
+        if !self.enabled(record.metadata()) {
+            return;
+        }
+
+        RawConsole
+            .write_fmt(format_args!("[{}] {}\n", record.level(), record.args()))
+            .unwrap();
+    }
+
+    fn flush(&self) {}
+}
+
+pub fn init() {
+    static LOGGER: SimpleLogger = SimpleLogger;
+    log::set_logger(&LOGGER).unwrap();
+
+    // TODO: get log level from boot env
+    log::set_max_level(LevelFilter::Trace);
+}

src/main.rs

@@ -0,0 +1,6 @@
+#![no_std]
+#![no_main]
+
+#[allow(unused_imports)]
+#[allow(clippy::single_component_path_imports)]
+use tiny_os;