ch2: Applications

user_lib
user apps

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);
+}