ch2: Applications

user_lib
user apps

os/.cargo/config.toml

@@ -0,0 +1,7 @@
+[build]
+target = "riscv64gc-unknown-none-elf"
+
+[target.riscv64gc-unknown-none-elf]
+rustflags = [
+    "-Clink-arg=-Tsrc/linker.ld", "-Cforce-frame-pointers=yes"
+]

os/.gitignore

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

os/Cargo.lock

@@ -0,0 +1,32 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "log"
+version = "0.4.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"
+
+[[package]]
+name = "os"
+version = "0.1.0"
+dependencies = [
+ "log",
+ "sbi-rt",
+]
+
+[[package]]
+name = "sbi-rt"
+version = "0.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fbaa69be1eedc61c426e6d489b2260482e928b465360576900d52d496a58bd0"
+dependencies = [
+ "sbi-spec",
+]
+
+[[package]]
+name = "sbi-spec"
+version = "0.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6e36312fb5ddc10d08ecdc65187402baba4ac34585cb9d1b78522ae2358d890"

os/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "os"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+log = "0.4.22"
+sbi-rt = "0.0.3"

os/src/console.rs

@@ -0,0 +1,29 @@
+use core::fmt::{self, Write};
+use crate::sbi;
+
+struct Stdout;
+
+impl Write for Stdout {
+    fn write_str(&mut self, s: &str) -> core::fmt::Result {
+        sbi::console_write(s.as_bytes());
+        Ok(())
+    }
+}
+
+pub fn print(args: fmt::Arguments) {
+    Stdout.write_fmt(args).unwrap();
+}
+
+#[macro_export]
+macro_rules! print {
+    ($fmt: literal $(, $($arg: tt)+)?) => {
+        $crate::console::print(format_args!($fmt $(, $($arg)+)?));
+    };
+}
+
+#[macro_export]
+macro_rules! println {
+    ($fmt: literal $(, $($arg: tt)+)?) => {
+        $crate::console::print(format_args!(concat!($fmt, "\n") $(, $($arg)+)?));
+    };
+}

os/src/entry.asm

@@ -0,0 +1,12 @@
+    .section .text.entry
+    .globl _start
+_start:
+    la sp, boot_start_top
+    call rust_main
+
+    .section .bss.stack
+    .globl boot_stack_lower_bound
+boot_stack_lower_bound:
+    .space 4096 * 16
+    .globl boot_start_top
+boot_start_top:

os/src/lang_items.rs

@@ -0,0 +1,18 @@
+use core::panic::PanicInfo;
+use crate::{sbi, println};
+
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    let err = info.message().as_str().unwrap();
+    if let Some(location) = info.location() {
+        println!(
+            "Panicked at {}:{} {}",
+            location.file(),
+            location.line(),
+            err
+        );
+    } else {
+        println!("Panicked: {}", err);
+    }
+    sbi::shutdown(true)
+}

os/src/linker.ld

@@ -0,0 +1,48 @@
+OUTPUT_ARCH(riscv)
+ENTRY(_start)
+BASE_ADDRESS = 0x80200000;
+
+SECTIONS
+{
+    . = BASE_ADDRESS;
+    skernel = .;
+
+    stext = .;
+    .text : {
+        *(.text.entry)
+        *(.text .text.*)
+    }
+
+    . = ALIGN(4K);
+    etext = .;
+    srodata = .;
+    .rodata : {
+        *(.data .rodata.*)
+        *(.srodata .srodata.*)
+    }
+
+    . = ALIGN(4K);
+    erodata = .;
+    sdata = .;
+    .data : {
+        *(.data .data.*)
+        *(.sdata .sdata.*)
+    }
+
+    . = ALIGN(4K);
+    edata = .;
+    .bss : {
+        *(.bss.stack)
+        sbss = .;
+        *(.bss .bss.*)
+        *(.sbss .sbss.*)
+    }
+
+    . = ALIGN(4K);
+    ebss = .;
+    ekernel = .;
+     
+    /DISCARD/ : {
+        *(.eh_frame)
+    }
+}

os/src/logger.rs

@@ -0,0 +1,42 @@
+use log::{Level, LevelFilter, Log};
+
+use crate::println;
+
+struct Logger;
+
+impl Log for Logger {
+    fn enabled(&self, _metadata: &log::Metadata) -> bool {
+        true
+    }
+
+    fn log(&self, record: &log::Record) {
+        if !self.enabled(record.metadata()) {
+            return;
+        }
+
+        let (color, level) = match record.level() {
+            Level::Error => (31, "ERR"),
+            Level::Warn  => (93, "WRN"),
+            Level::Info  => (34, "INF"),
+            Level::Debug => (32, "DBG"),
+            Level::Trace => (90, "TRC"),
+        };
+
+        println!("\x1b[{}m{}\x1b[0m \x1b[1m{}\x1b[0m {}", color, level, record.target(), record.args());
+    }
+
+    fn flush(&self) {}
+}
+
+pub fn init() {
+    static LOGGER: Logger = Logger;
+    log::set_logger(&LOGGER).unwrap();
+    log::set_max_level(match option_env!("LOG") {
+        Some("ERROR") => LevelFilter::Error,
+        Some("WARN")  => LevelFilter::Warn,
+        Some("INFO")  => LevelFilter::Info,
+        Some("DEBUG") => LevelFilter::Debug,
+        Some("TRACE") => LevelFilter::Trace,
+        _ => LevelFilter::Off,
+    });
+}

os/src/main.rs

@@ -0,0 +1,65 @@
+#![no_std]
+#![no_main]
+
+mod lang_items;
+mod sbi;
+mod logger;
+
+#[macro_use]
+mod console;
+
+use core::arch::global_asm;
+use log::{debug, error, info, trace, warn};
+
+global_asm!(include_str!("entry.asm"));
+
+#[no_mangle]
+pub fn rust_main() -> ! {
+    clear_bss();
+    logger::init();
+
+    print_system_info();
+    print_to_console();
+
+    panic!("Shutdown machine!");
+}
+
+fn clear_bss() {
+    extern "C" {
+        fn sbss();
+        fn ebss();
+    }
+    (sbss as usize..ebss as usize).for_each(|a| {
+        unsafe { (a as *mut u8).write_volatile(0) }
+    });
+}
+
+fn print_to_console() {
+    sbi::console_write_byte('O' as u8);
+    sbi::console_write_byte('K' as u8);
+    sbi::console_write_byte('\n' as u8);
+
+    trace!("Hello World.");
+    debug!("Hello World.");
+    info!("Hello World.");
+    warn!("Hello World.");
+    error!("Hello World.");
+}
+
+fn print_system_info() {
+    extern "C" {
+        fn stext();
+        fn etext();
+        fn sdata();
+        fn edata();
+        fn srodata();
+        fn erodata();
+        fn sbss();
+        fn ebss();
+    }
+
+    info!(".text [{:#x}, {:#x}]", stext as usize, etext as usize);
+    info!(".rodata [{:#x}, {:#x}]", srodata as usize, erodata as usize);
+    info!(".data [{:#x}, {:#x}]", sdata as usize, edata as usize);
+    info!(".bss [{:#x}, {:#x}]", sbss as usize, ebss as usize);
+}

os/src/sbi.rs

@@ -0,0 +1,19 @@
+pub fn console_write_byte(c: u8) {
+    sbi_rt::console_write_byte(c);
+}
+
+pub fn console_write(bytes: &[u8]) {
+    let range = bytes.as_ptr_range();
+    let bytes = sbi_rt::Physical::new(bytes.len(), range.start as usize, range.end as usize);
+    sbi_rt::console_write(bytes);
+}
+
+pub fn shutdown(failure: bool) -> ! {
+    use sbi_rt::{system_reset, NoReason, Shutdown, SystemFailure};
+    if !failure {
+        system_reset(Shutdown, NoReason);
+    } else {
+        system_reset(Shutdown, SystemFailure);
+    }
+    unreachable!()
+}