step 3

.cargo/config

@@ -1,2 +1,8 @@
 [build]
 target = "riscv64gc-unknown-none-elf"
+
+
+[target.riscv64gc-unknown-none-elf]
+rustflags = [
+    "-Clink-arg=-Tsrc/linker.ld", "-Cforce-frame-pointers=yes"
+]

docs/3 打印.md

@@ -1,3 +1,119 @@
 ## 打印
 
-退出看不出来，看来只好打印了，幸好 SBI 实现了打印，省去了自己实现驱动，调用系统调用就行了。
+退出看不出来，看来只好打印了，幸好 SBI 实现了打印，省去了自己实现驱动，调用系统调用就行了。
+
+实现系统调用，在 scall_sbi/mod.rs 中
+
+```rust
+#[inline(always)]
+fn scall(which: usize, arg0: usize, arg1: usize, arg2: usize) -> usize {
+    let mut ret;
+    unsafe {
+        llvm_asm!("ecall"
+            : "={x10}" (ret)
+            : "{x10}" (arg0), "{x11}" (arg1), "{x12}" (arg2), "{x17}" (which)
+            : "memory"
+            : "volatile"
+        );
+    }
+    ret
+}
+const SBI_CONSOLE_PUTCHAR: usize = 1;
+const SBI_SHUTDOWN: usize = 8;
+
+pub fn shutdown() -> ! {
+    scall(SBI_SHUTDOWN, 0, 0, 0);
+    panic!("It should shutdown!");
+}
+
+pub fn put_char(c: usize) {
+    scall(SBI_CONSOLE_PUTCHAR, c, 0, 0);
+}
+
+```
+
+建立 console.rs 调用刚才的系统调用，内容是
+
+```rust
+use core::fmt::{self, Write};
+
+use crate::scall_sbi::put_char;
+
+struct STDOUT;
+
+impl Write for STDOUT {
+    fn write_str(&mut self, s: &str) -> core::fmt::Result {
+        for c in s.chars() {
+            put_char(c as usize);
+        }
+        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)+)?));
+    }
+}
+```
+
+说明一下
+
+- 利用 宏 + core::fmt::Write 来解析参数
+
+main.rs 里就可以调用宏输出了，这时 main.rs 的内容
+
+```rust
+#![feature(llvm_asm)]
+#![feature(global_asm)]
+#![no_std]
+#![no_main]
+
+use scall_sbi::shutdown;
+
+mod lang;
+mod scall_sbi;
+#[macro_use]
+mod console;
+
+global_asm!(include_str!("stack.asm"));
+
+#[no_mangle]
+extern "C" fn rust_main() ->! {
+    println!("hello OS");
+    shutdown();
+}
+```
+
+编译一下，make build，编译过了，运行一下 make run 也成功了，输出
+
+```
+[rustsbi] RustSBI version 0.2.0-alpha.3
+.______       __    __      _______.___________.  _______..______   __
+|   _  \     |  |  |  |    /       |           | /       ||   _  \ |  |
+|  |_)  |    |  |  |  |   |   (----`---|  |----`|   (----`|  |_)  ||  |
+|      /     |  |  |  |    \   \       |  |      \   \    |   _  < |  |
+|  |\  \----.|  `--'  |.----)   |      |  |  .----)   |   |  |_)  ||  |
+| _| `._____| \______/ |_______/       |__|  |_______/    |______/ |__|
+
+[rustsbi] Platform: K210 (Version 0.2.0)
+[rustsbi] misa: RV64ACDFIMSU
+[rustsbi] mideleg: 0x22
+[rustsbi] medeleg: 0x1ab
+[rustsbi] Kernel entry: 0x80020000
+hello OS
+[rustsbi] reset triggered! todo: shutdown all harts on k210; program halt. Type: 0, reason: 0
+```
+

os/src/console.rs

@@ -0,0 +1,32 @@
+use core::fmt::{self, Write};
+
+use crate::scall_sbi::put_char;
+
+struct STDOUT;
+
+impl Write for STDOUT {
+    fn write_str(&mut self, s: &str) -> core::fmt::Result {
+        for c in s.chars() {
+            put_char(c as usize);
+        }
+        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/main.rs

@@ -7,10 +7,13 @@ use scall_sbi::shutdown;
 
 mod lang;
 mod scall_sbi;
+#[macro_use]
+mod console;
 
 global_asm!(include_str!("stack.asm"));
 
 #[no_mangle]
 extern "C" fn rust_main() ->! {
+    println!("hello OS");
     shutdown();
 }

os/src/scall_sbi/mod.rs

@@ -11,10 +11,14 @@ fn scall(which: usize, arg0: usize, arg1: usize, arg2: usize) -> usize {
     }
     ret
 }
-
+const SBI_CONSOLE_PUTCHAR: usize = 1;
 const SBI_SHUTDOWN: usize = 8;
 
 pub fn shutdown() -> ! {
     scall(SBI_SHUTDOWN, 0, 0, 0);
     panic!("It should shutdown!");
 }
+
+pub fn put_char(c: usize) {
+    scall(SBI_CONSOLE_PUTCHAR, c, 0, 0);
+}