初始化内核(其实就是把ch1的src复制过来)

ch2/os/Cargo.toml

@@ -5,4 +5,6 @@ edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
-[dependencies]
+# 设置release模式下保存调试信息
+[profile.release]
+debug=true

ch2/os/Makefile

@@ -0,0 +1,51 @@
+TARGET := riscv64gc-unknown-none-elf
+KERNEL_ENTRY := 0x80200000
+MODE := release
+KERNEL_ELF := target/$(TARGET)/$(MODE)/os
+KERNEL_BIN := $(KERNEL_ELF).bin
+SYMBOL_MAP := target/system.map
+QEMU_CMD_PATH := /Users/zhangxinyu/Downloads/qemu-7.0.0/build/qemu-system-riscv64
+QEMU_PID = $(shell ps aux | grep "[q]emu-system' | awk '{print $$2}")
+OBJDUMP := rust-objdump --arch-name=riscv64
+OBJCOPY := rust-objcopy --binary-architecture=riscv64
+
+RUST_FLAGS := -Clink-arg=-Tsrc/linker.ld  # 使用我们自己的链接脚本
+RUST_FLAGS += -Cforce-frame-pointers=yes  # 强制编译器生成帧指针
+RUST_FLAGS:=$(strip ${RUST_FLAGS})
+
+# 编译elf文件
+build_elf: clean
+	CARGO_BUILD_RUSTFLAGS="$(RUST_FLAGS)" \
+ 	cargo build --$(MODE) --target=$(TARGET)
+
+# 导出一个符号表, 供我们查看
+$(SYMBOL_MAP):build_elf
+	nm $(KERNEL_ELF) | sort > $(SYMBOL_MAP)
+
+# 丢弃内核可执行elf文件中的元数据得到内核镜像
+$(KERNEL_BIN): build_elf
+	@$(OBJCOPY) $(KERNEL_ELF) --strip-all -O binary $@
+
+
+debug:build_elf $(KERNEL_BIN) $(SYMBOL_MAP) kill
+	$(QEMU_CMD_PATH) \
+		-machine virt \
+		-display none \
+		-daemonize \
+		-bios ../bootloader/rustsbi-qemu.bin \
+		-device loader,file=$(KERNEL_BIN),addr=$(KERNEL_ENTRY) \
+		-s -S
+
+run:build_elf $(KERNEL_BIN) $(SYMBOL_MAP) kill
+	$(QEMU_CMD_PATH) \
+		-machine virt \
+		-nographic \
+		-bios ../bootloader/rustsbi-qemu.bin \
+		-device loader,file=$(KERNEL_BIN),addr=$(KERNEL_ENTRY)
+
+clean:
+	rm -rf ./target*
+
+kill:
+	-kill -9 $(QEMU_PID)
+

ch2/os/src/entry.asm

@@ -0,0 +1,15 @@
+.section .text.entry
+.globl _start  // 声明_start是全局符号
+_start:
+    la sp, boot_stack_top_bound
+    call rust_main
+
+
+
+// 声明栈空间 后续 .bss.stack 会被link脚本链接到 .bss段
+    .section .bss.stack
+    .globl boot_stack_lower_bound  // 栈低地址公开为全局符号
+    .globl boot_stack_top_bound  // 栈高地址公开为全局符号
+boot_stack_lower_bound:
+    .space 4096 * 16
+boot_stack_top_bound:

ch2/os/src/lang_items.rs

@@ -0,0 +1,2 @@
+pub mod panic;
+pub mod console;

ch2/os/src/lang_items/console.rs

@@ -0,0 +1,33 @@
+
+use crate::sbi::console_put_char;
+use core::fmt::{self, Write};
+
+struct Stdout;
+
+impl Write for Stdout{
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        for c in s.chars() {
+            console_put_char(c as usize);
+        }
+        Ok(())
+    }
+}
+
+// 用函数包装一下, 表示传进来的参数满足Arguments trait, 然后供宏调用
+pub fn print(args: fmt::Arguments) {
+    Stdout.write_fmt(args).unwrap();
+}
+
+#[macro_export]  // 导入这个文件即可使用这些宏
+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)+)?));
+    }
+}

ch2/os/src/lang_items/panic.rs

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

ch2/os/src/linker.ld

@@ -0,0 +1,48 @@
+OUTPUT_ARCH(riscv)  /* 目标平台 */
+ENTRY(_start)  /* 设置程序入口点为entry.asm中定义的全局符号 */
+BASE_ADDRESS = 0x80200000;  /* 一个常量, 我们的kernel将来加载到这个物理地址 */
+
+SECTIONS
+{
+    . = BASE_ADDRESS;  /* 我们对 . 进行赋值, 调整接下来的段的开始位置放在我们定义的常量出 */
+/*    skernel = .;*/
+
+    stext = .;  /* .text段的开始位置 */
+    .text : {  /* 表示生成一个为 .text的段, 花括号内按照防止顺序表示将输入文件中的哪些段放在 当前.text段中 */
+        *(.text.entry)  /* entry.asm中, 我们自己定义的.text.entry段, 被放在顶部*/
+        *(.text .text.*)
+    }
+
+    . = ALIGN(4K);
+    etext = .;
+    srodata = .;
+    .rodata : {
+        *(.rodata .rodata.*)
+        *(.srodata .srodata.*)
+    }
+
+    . = ALIGN(4K);
+    erodata = .;
+    sdata = .;
+    .data : {
+        *(.data .data.*)
+        *(.sdata .sdata.*)
+    }
+
+    . = ALIGN(4K);
+    edata = .;
+    .bss : {
+        *(.bss.stack)  /* 全局符号 sbss 和 ebss 分别指向 .bss 段除 .bss.stack 以外的起始和终止地址(.bss.stack是我们在entry.asm中定义的栈) */
+        sbss = .;
+        *(.bss .bss.*)
+        *(.sbss .sbss.*)
+    }
+
+    . = ALIGN(4K);
+    ebss = .;
+    ekernel = .;
+
+    /DISCARD/ : {
+        *(.eh_frame)
+    }
+}

ch2/os/src/main.rs

@@ -1,3 +1,41 @@
-fn main() {
+#![feature(panic_info_message)]
-    println!("Hello, world!");
+#![no_std]
+#![no_main]
+
+use core::arch::global_asm;
+use sbi::{console_put_char, shutdown};
+use lang_items::console;
+
+mod lang_items;
+mod sbi;
+
+// 汇编脚本引入, 调整内核的内存布局之后, 会跳入到 rust_main中执行
+global_asm!(include_str!("entry.asm"));
+
+extern "C" {
+    fn stext();
+    fn etext();
+    fn sbss();
+    fn ebss();
+    fn boot_stack_top_bound();
+    fn boot_stack_lower_bound();
+}
+
+#[no_mangle]
+pub fn rust_main(){
+    init_bss();
+
+    println!("stext: {:#x}, etext: {:#x}", stext as usize, etext as usize);
+    println!("sbss: {:#x}, ebss: {:#x}", sbss as usize, ebss as usize);
+    println!("boot_stack_top_bound: {:#x}, boot_stack_lower_bound: {:#x}", boot_stack_top_bound as usize, boot_stack_lower_bound as usize);
+
+    panic!("my panic");
+}
+
+/// ## 初始化bss段
+///
+fn init_bss() {
+    unsafe {
+        (sbss as usize..ebss as usize).for_each(|p| (p as *mut u8).write_unaligned(0))
+    }
 }

ch2/os/src/sbi.rs

@@ -0,0 +1,40 @@
+use core::arch::asm;
+
+// legacy extensions: ignore fid
+const SBI_SET_TIMER: usize = 0;
+const SBI_CONSOLE_PUTCHAR: usize = 1;
+const SBI_CONSOLE_GETCHAR: usize = 2;
+const SBI_CLEAR_IPI: usize = 3;
+const SBI_SEND_IPI: usize = 4;
+const SBI_REMOTE_FENCE_I: usize = 5;
+const SBI_REMOTE_SFENCE_VMA: usize = 6;
+const SBI_REMOTE_SFENCE_VMA_ASID: usize = 7;
+
+// system reset extension
+const SRST_EXTENSION: usize = 0x53525354;
+const SBI_SHUTDOWN: usize = 0;
+
+#[inline(always)]
+fn sbi_call(eid: usize, fid: usize, arg0: usize, arg1: usize, arg2: usize) -> usize {
+    let mut ret;
+    unsafe {
+        asm!(
+        "ecall",
+        inlateout("x10") arg0 => ret,
+        in("x11") arg1,
+        in("x12") arg2,
+        in("x16") fid,
+        in("x17") eid,
+        );
+    }
+    ret
+}
+
+pub fn console_put_char(c: usize) {
+    sbi_call(SBI_CONSOLE_PUTCHAR, 0, c, 0, 0);
+}
+
+pub fn shutdown() -> ! {
+    sbi_call(SRST_EXTENSION, SBI_SHUTDOWN, 0, 0, 0);
+    panic!("It should shutdown!")
+}

ch2/user/Makefile

@@ -20,6 +20,7 @@ build_elf: clean
  	cargo build --$(MODE) --target=$(TARGET)
 
 
+# 把每个elf文件去掉无关代码
 build: build_elf
 	@$(foreach elf, $(ELFS), $(OBJCOPY) $(elf) --strip-all -O binary $(patsubst $(TARGET_DIR)/%, $(TARGET_DIR)/%.bin, $(elf));)