diff --git a/03_hacky_hello_world/README.CN.md b/03_hacky_hello_world/README.CN.md new file mode 100644 index 00000000..2c6dfd8b --- /dev/null +++ b/03_hacky_hello_world/README.CN.md @@ -0,0 +1,371 @@ +# 教程 03 - Hacky Hello World + +## tl;dr + +- 全面介绍`println!()` 宏以便尽早启用"printf debugging"。 +- 为了保持教程长度合理，打印函数目前 "滥用" 了 QEMU 属性，该属性允许我们在没有正确设置的情况下使用树莓派的`UART`。 +- 使用真正的硬件`UART 在以下教程中逐步启用。 + +## 值得注意的补充 + +- `src/console.rs`为控制台命令和通过`console::console()`对内核控制台的全局访问引入了接口`Traits`。 +- `src/bsp/raspberrypi/console.rs` 实现QEMU仿真UART的接口。 +- 紧急处理程序使用新的`println!()`以显示用户错误消息。 +- 有一个新的Makefile目录`make test`，用于自动测试。它在`QEMU`中引导编译后的内核，并检查内核生成的预期输出字符串。 + - 在本教程中，它检查字符串`Stopping here`，该字符串由`panic!()`在`main.rs`的末尾。 + +## 测试一下 + +QEMU不再以汇编模式运行。从现在起，它将显示`console`的输出。 + +```console +$ make qemu +[...] + +Hello from Rust! +Kernel panic! + +Panic location: + File 'src/main.rs', line 126, column 5 + +Stopping here. +``` + +## 与上面不同 +```diff + +diff -uNr 02_runtime_init/Cargo.toml 03_hacky_hello_world/Cargo.toml +--- 02_runtime_init/Cargo.toml ++++ 03_hacky_hello_world/Cargo.toml +@@ -1,6 +1,6 @@ + [package] + name = "mingo" +-version = "0.2.0" ++version = "0.3.0" + authors = ["Andre Richter "] + edition = "2021" + + +diff -uNr 02_runtime_init/Makefile 03_hacky_hello_world/Makefile +--- 02_runtime_init/Makefile ++++ 03_hacky_hello_world/Makefile +@@ -24,7 +24,7 @@ + KERNEL_BIN = kernel8.img + QEMU_BINARY = qemu-system-aarch64 + QEMU_MACHINE_TYPE = raspi3 +- QEMU_RELEASE_ARGS = -d in_asm -display none ++ QEMU_RELEASE_ARGS = -serial stdio -display none + OBJDUMP_BINARY = aarch64-none-elf-objdump + NM_BINARY = aarch64-none-elf-nm + READELF_BINARY = aarch64-none-elf-readelf +@@ -35,7 +35,7 @@ + KERNEL_BIN = kernel8.img + QEMU_BINARY = qemu-system-aarch64 + QEMU_MACHINE_TYPE = +- QEMU_RELEASE_ARGS = -d in_asm -display none ++ QEMU_RELEASE_ARGS = -serial stdio -display none + OBJDUMP_BINARY = aarch64-none-elf-objdump + NM_BINARY = aarch64-none-elf-nm + READELF_BINARY = aarch64-none-elf-readelf +@@ -85,17 +85,20 @@ + --strip-all \ + -O binary + +-EXEC_QEMU = $(QEMU_BINARY) -M $(QEMU_MACHINE_TYPE) ++EXEC_QEMU = $(QEMU_BINARY) -M $(QEMU_MACHINE_TYPE) ++EXEC_TEST_DISPATCH = ruby ../common/tests/dispatch.rb + + ##------------------------------------------------------------------------------ + ## Dockerization + ##------------------------------------------------------------------------------ +-DOCKER_CMD = docker run -t --rm -v $(shell pwd):/work/tutorial -w /work/tutorial +-DOCKER_CMD_INTERACT = $(DOCKER_CMD) -i ++DOCKER_CMD = docker run -t --rm -v $(shell pwd):/work/tutorial -w /work/tutorial ++DOCKER_CMD_INTERACT = $(DOCKER_CMD) -i ++DOCKER_ARG_DIR_COMMON = -v $(shell pwd)/../common:/work/common + + # DOCKER_IMAGE defined in include file (see top of this file). + DOCKER_QEMU = $(DOCKER_CMD_INTERACT) $(DOCKER_IMAGE) + DOCKER_TOOLS = $(DOCKER_CMD) $(DOCKER_IMAGE) ++DOCKER_TEST = $(DOCKER_CMD) $(DOCKER_ARG_DIR_COMMON) $(DOCKER_IMAGE) + + + +@@ -190,3 +193,27 @@ + $(call color_header, "Launching nm") + @$(DOCKER_TOOLS) $(NM_BINARY) --demangle --print-size $(KERNEL_ELF) | sort | rustfilt + ++ ++ ++##-------------------------------------------------------------------------------------------------- ++## Testing targets ++##-------------------------------------------------------------------------------------------------- ++.PHONY: test test_boot ++ ++ifeq ($(QEMU_MACHINE_TYPE),) # QEMU is not supported for the board. ++ ++test_boot test: ++ $(call color_header, "$(QEMU_MISSING_STRING)") ++ ++else # QEMU is supported. ++ ++##------------------------------------------------------------------------------ ++## Run boot test ++##------------------------------------------------------------------------------ ++test_boot: $(KERNEL_BIN) ++ $(call color_header, "Boot test - $(BSP)") ++ @$(DOCKER_TEST) $(EXEC_TEST_DISPATCH) $(EXEC_QEMU) $(QEMU_RELEASE_ARGS) -kernel $(KERNEL_BIN) ++ ++test: test_boot ++ ++endif + +diff -uNr 02_runtime_init/src/bsp/raspberrypi/console.rs 03_hacky_hello_world/src/bsp/raspberrypi/console.rs +--- 02_runtime_init/src/bsp/raspberrypi/console.rs ++++ 03_hacky_hello_world/src/bsp/raspberrypi/console.rs +@@ -0,0 +1,47 @@ ++// SPDX-License-Identifier: MIT OR Apache-2.0 ++// ++// Copyright (c) 2018-2022 Andre Richter ++ ++//! BSP console facilities. ++ ++use crate::console; ++use core::fmt; ++ ++//-------------------------------------------------------------------------------------------------- ++// Private Definitions ++//-------------------------------------------------------------------------------------------------- ++ ++/// A mystical, magical device for generating QEMU output out of the void. ++struct QEMUOutput; ++ ++//-------------------------------------------------------------------------------------------------- ++// Private Code ++//-------------------------------------------------------------------------------------------------- ++ ++/// Implementing `core::fmt::Write` enables usage of the `format_args!` macros, which in turn are ++/// used to implement the `kernel`'s `print!` and `println!` macros. By implementing `write_str()`, ++/// we get `write_fmt()` automatically. ++/// ++/// See [`src/print.rs`]. ++/// ++/// [`src/print.rs`]: ../../print/index.html ++impl fmt::Write for QEMUOutput { ++ fn write_str(&mut self, s: &str) -> fmt::Result { ++ for c in s.chars() { ++ unsafe { ++ core::ptr::write_volatile(0x3F20_1000 as *mut u8, c as u8); ++ } ++ } ++ ++ Ok(()) ++ } ++} ++ ++//-------------------------------------------------------------------------------------------------- ++// Public Code ++//-------------------------------------------------------------------------------------------------- ++ ++/// Return a reference to the console. ++pub fn console() -> impl console::interface::Write { ++ QEMUOutput {} ++} + +diff -uNr 02_runtime_init/src/bsp/raspberrypi.rs 03_hacky_hello_world/src/bsp/raspberrypi.rs +--- 02_runtime_init/src/bsp/raspberrypi.rs ++++ 03_hacky_hello_world/src/bsp/raspberrypi.rs +@@ -4,4 +4,5 @@ + + //! Top-level BSP file for the Raspberry Pi 3 and 4. + ++pub mod console; + pub mod cpu; + +diff -uNr 02_runtime_init/src/console.rs 03_hacky_hello_world/src/console.rs +--- 02_runtime_init/src/console.rs ++++ 03_hacky_hello_world/src/console.rs +@@ -0,0 +1,32 @@ ++// SPDX-License-Identifier: MIT OR Apache-2.0 ++// ++// Copyright (c) 2018-2022 Andre Richter ++ ++//! System console. ++ ++use crate::bsp; ++ ++//-------------------------------------------------------------------------------------------------- ++// Public Definitions ++//-------------------------------------------------------------------------------------------------- ++ ++/// Console interfaces. ++pub mod interface { ++ /// Console write functions. ++ /// ++ /// `core::fmt::Write` is exactly what we need for now. Re-export it here because ++ /// implementing `console::Write` gives a better hint to the reader about the ++ /// intention. ++ pub use core::fmt::Write; ++} ++ ++//-------------------------------------------------------------------------------------------------- ++// Public Code ++//-------------------------------------------------------------------------------------------------- ++ ++/// Return a reference to the console. ++/// ++/// This is the global console used by all printing macros. ++pub fn console() -> impl interface::Write { ++ bsp::console::console() ++} + +diff -uNr 02_runtime_init/src/main.rs 03_hacky_hello_world/src/main.rs +--- 02_runtime_init/src/main.rs ++++ 03_hacky_hello_world/src/main.rs +@@ -107,12 +107,16 @@ + //! 2. Once finished with architectural setup, the arch code calls `kernel_init()`. + + #![feature(asm_const)] ++#![feature(format_args_nl)] ++#![feature(panic_info_message)] + #![no_main] + #![no_std] + + mod bsp; ++mod console; + mod cpu; + mod panic_wait; ++mod print; + + /// Early init code. + /// +@@ -120,5 +124,7 @@ + /// + /// - Only a single core must be active and running this function. + unsafe fn kernel_init() -> ! { +- panic!() ++ println!("Hello from Rust!"); ++ ++ panic!("Stopping here.") + } + +diff -uNr 02_runtime_init/src/panic_wait.rs 03_hacky_hello_world/src/panic_wait.rs +--- 02_runtime_init/src/panic_wait.rs ++++ 03_hacky_hello_world/src/panic_wait.rs +@@ -4,14 +4,61 @@ + + //! A panic handler that infinitely waits. + +-use crate::cpu; ++use crate::{cpu, println}; + use core::panic::PanicInfo; + + //-------------------------------------------------------------------------------------------------- + // Private Code + //-------------------------------------------------------------------------------------------------- + ++/// Stop immediately if called a second time. ++/// ++/// # Note ++/// ++/// Using atomics here relieves us from needing to use `unsafe` for the static variable. ++/// ++/// On `AArch64`, which is the only implemented architecture at the time of writing this, ++/// [`AtomicBool::load`] and [`AtomicBool::store`] are lowered to ordinary load and store ++/// instructions. They are therefore safe to use even with MMU + caching deactivated. ++/// ++/// [`AtomicBool::load`]: core::sync::atomic::AtomicBool::load ++/// [`AtomicBool::store`]: core::sync::atomic::AtomicBool::store ++fn panic_prevent_reenter() { ++ use core::sync::atomic::{AtomicBool, Ordering}; ++ ++ #[cfg(not(target_arch = "aarch64"))] ++ compile_error!("Add the target_arch to above's check if the following code is safe to use"); ++ ++ static PANIC_IN_PROGRESS: AtomicBool = AtomicBool::new(false); ++ ++ if !PANIC_IN_PROGRESS.load(Ordering::Relaxed) { ++ PANIC_IN_PROGRESS.store(true, Ordering::Relaxed); ++ ++ return; ++ } ++ ++ cpu::wait_forever() ++} ++ + #[panic_handler] +-fn panic(_info: &PanicInfo) -> ! { ++fn panic(info: &PanicInfo) -> ! { ++ // Protect against panic infinite loops if any of the following code panics itself. ++ panic_prevent_reenter(); ++ ++ let (location, line, column) = match info.location() { ++ Some(loc) => (loc.file(), loc.line(), loc.column()), ++ _ => ("???", 0, 0), ++ }; ++ ++ println!( ++ "Kernel panic!\n\n\ ++ Panic location:\n File '{}', line {}, column {}\n\n\ ++ {}", ++ location, ++ line, ++ column, ++ info.message().unwrap_or(&format_args!("")), ++ ); ++ + cpu::wait_forever() + } + +diff -uNr 02_runtime_init/src/print.rs 03_hacky_hello_world/src/print.rs +--- 02_runtime_init/src/print.rs ++++ 03_hacky_hello_world/src/print.rs +@@ -0,0 +1,38 @@ ++// SPDX-License-Identifier: MIT OR Apache-2.0 ++// ++// Copyright (c) 2018-2022 Andre Richter ++ ++//! Printing. ++ ++use crate::console; ++use core::fmt; ++ ++//-------------------------------------------------------------------------------------------------- ++// Public Code ++//-------------------------------------------------------------------------------------------------- ++ ++#[doc(hidden)] ++pub fn _print(args: fmt::Arguments) { ++ use console::interface::Write; ++ ++ console::console().write_fmt(args).unwrap(); ++} ++ ++/// Prints without a newline. ++/// ++/// Carbon copy from ++#[macro_export] ++macro_rules! print { ++ ($($arg:tt)*) => ($crate::print::_print(format_args!($($arg)*))); ++} ++ ++/// Prints with a newline. ++/// ++/// Carbon copy from ++#[macro_export] ++macro_rules! println { ++ () => ($crate::print!("\n")); ++ ($($arg:tt)*) => ({ ++ $crate::print::_print(format_args_nl!($($arg)*)); ++ }) ++} + +diff -uNr 02_runtime_init/tests/boot_test_string.rb 03_hacky_hello_world/tests/boot_test_string.rb +--- 02_runtime_init/tests/boot_test_string.rb ++++ 03_hacky_hello_world/tests/boot_test_string.rb +@@ -0,0 +1,3 @@ ++# frozen_string_literal: true ++ ++EXPECTED_PRINT = 'Stopping here' + +```