From e33464e47dd309e64c27af7c53997a4c3b7eef19 Mon Sep 17 00:00:00 2001
From: Sainnhe Park <sainnhe@gmail.com>
Date: Wed, 1 Dec 2021 11:41:32 +0800
Subject: [PATCH] Finish basic structure

---
 Cargo.lock  |  7 +++++++
 Cargo.toml  |  7 +++++--
 src/main.rs | 20 ++++++++++++++++++--
 3 files changed, 30 insertions(+), 4 deletions(-)
 create mode 100644 Cargo.lock

diff --git a/Cargo.lock b/Cargo.lock
new file mode 100644
index 0000000..9678ac5
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "anos"
+version = "0.1.0"
diff --git a/Cargo.toml b/Cargo.toml
index 6c4a86b..793a53b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,8 +1,11 @@
 [package]
 name = "anos"
 version = "0.1.0"
+authors = ["Sainnhe Park <sainnhe@gmail.com>"]
 edition = "2021"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[profile.dev]
+panic = "abort"         # 禁用 panic 时的栈展开
 
-[dependencies]
+[profile.release]
+panic = "abort"         # 禁用 panic 时的栈展开
diff --git a/src/main.rs b/src/main.rs
index e7a11a9..3457e83 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,19 @@
-fn main() {
-    println!("Hello, world!");
+#![no_std]      // 不链接 Rust 标准库
+#![no_main]     // 禁用 main 入口点，因为没有运行时
+
+use core::panic::PanicInfo;
+
+#[no_mangle]    // 不重整函数名，否则编译器可能会生成名为 _ZN3blog_os4_start7hb173fedf945531caE 的函数
+// extern "C" 告诉编译器这个函数应当使用 C 语言的调用约定
+// 函数名为 _start 是因为大多数系统默认用这个名字作为入口点名称
+// -> ! 代表这是一个发散函数，不允许有任何返回值，因为它不会被任何函数调用，而是将直接被 bootloader 调用
+pub extern "C" fn _start() -> ! {
+    loop {}
+}
+
+#[panic_handler]
+// panic! 时将会进行栈展开，执行各种 drop 函数来回收垃圾
+// 禁用标准库之后，这些东西就都没有了，我们需要把它重写一遍
+fn panic(_info: &PanicInfo) -> ! {
+    loop {}
 }