ch2: Trap handling

AppManager

Cargo.lock

@@ -1,32 +0,0 @@
-# This file is automatically @generated by Cargo.
-# It is not intended for manual editing.
-version = 3
-
-[[package]]
-name = "log"
-version = "0.4.22"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"
-
-[[package]]
-name = "os"
-version = "0.1.0"
-dependencies = [
- "log",
- "sbi-rt",
-]
-
-[[package]]
-name = "sbi-rt"
-version = "0.0.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7fbaa69be1eedc61c426e6d489b2260482e928b465360576900d52d496a58bd0"
-dependencies = [
- "sbi-spec",
-]
-
-[[package]]
-name = "sbi-spec"
-version = "0.0.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6e36312fb5ddc10d08ecdc65187402baba4ac34585cb9d1b78522ae2358d890"

README.md

@@ -2,12 +2,24 @@
 
 ## Build
 
+### in dir `user`
+
+``` bash
+cargo build --release
+rust-objcopy --strip-all target/riscv64gc-unknown-none-elf/release/00_hello_world -O binary target/riscv64gc-unknown-none-elf/release/00_hello_world.bin
+...
+```
+
+### in dir `os`
+
 ``` bash
 LOG=TRACE cargo build --release
 ```
 
 ## Run
 
+rustsbi-qemu should be downloaded manually.
+
 ``` bash
 qemu-system-riscv64 -machine virt -nographic -bios target/riscv64gc-unknown-none-elf/release/rustsbi-qemu.bin -device loader,file=target/riscv64gc-unknown-none-elf/release/os
 ```

os/Cargo.lock

@@ -0,0 +1,132 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "critical-section"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "790eea4361631c5e7d22598ecd5723ff611904e3344ce8720784c93e3d83d40b"
+
+[[package]]
+name = "embedded-hal"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "361a90feb7004eca4019fb28352a9465666b24f840f5c3cddf0ff13920590b89"
+
+[[package]]
+name = "lazy_static"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
+dependencies = [
+ "spin",
+]
+
+[[package]]
+name = "log"
+version = "0.4.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a7a70ba024b9dc04c27ea2f0c0548feb474ec5c54bba33a7f72f873a39d07b24"
+
+[[package]]
+name = "os"
+version = "0.1.0"
+dependencies = [
+ "lazy_static",
+ "log",
+ "riscv",
+ "sbi-rt",
+]
+
+[[package]]
+name = "paste"
+version = "1.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.89"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f139b0662de085916d1fb67d2b4169d1addddda1919e696f3252b740b629986e"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5b9d34b8991d19d98081b46eacdd8eb58c6f2b201139f7c5f643cc155a633af"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "riscv"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ea8ff73d3720bdd0a97925f0bf79ad2744b6da8ff36be3840c48ac81191d7a7"
+dependencies = [
+ "critical-section",
+ "embedded-hal",
+ "paste",
+ "riscv-macros",
+ "riscv-pac",
+]
+
+[[package]]
+name = "riscv-macros"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f265be5d634272320a7de94cea15c22a3bfdd4eb42eb43edc528415f066a1f25"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "riscv-pac"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8188909339ccc0c68cfb5a04648313f09621e8b87dc03095454f1a11f6c5d436"
+
+[[package]]
+name = "sbi-rt"
+version = "0.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fbaa69be1eedc61c426e6d489b2260482e928b465360576900d52d496a58bd0"
+dependencies = [
+ "sbi-spec",
+]
+
+[[package]]
+name = "sbi-spec"
+version = "0.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6e36312fb5ddc10d08ecdc65187402baba4ac34585cb9d1b78522ae2358d890"
+
+[[package]]
+name = "spin"
+version = "0.9.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
+
+[[package]]
+name = "syn"
+version = "2.0.87"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "25aa4ce346d03a6dcd68dd8b4010bcb74e54e62c90c573f394c46eae99aba32d"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e91b56cd4cadaeb79bbf1a5645f6b4f8dc5bde8834ad5894a8db35fda9efa1fe"

os/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "os"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+lazy_static = { version = "1.5.0", features = ["spin_no_std"] }
+log = "0.4.22"
+riscv = "0.12.1"
+sbi-rt = "0.0.3"

os/src/batch.rs

@@ -0,0 +1,135 @@
+use core::{arch::asm, mem, slice};
+
+use lazy_static::*;
+use log::info;
+
+use crate::{sbi::shutdown, sync::UPSafeCell, trap::TrapContext};
+
+const KERNEL_STACK_SIZE: usize = 4096 * 2;
+const USER_STACK_SIZE: usize = 4096 * 2;
+const MAX_APP_NUM: usize = 16;
+const APP_BASE_ADDRESS: usize = 0x80400000;
+const APP_SIZE_LIMIT: usize = 0x20000;
+
+#[repr(align(4096))]
+struct KernelStack {
+    data: [u8; KERNEL_STACK_SIZE],
+}
+#[repr(align(4096))]
+struct UserStack {
+    data: [u8; USER_STACK_SIZE],
+}
+
+static KERNEL_STACK: KernelStack = KernelStack {
+    data: [0; KERNEL_STACK_SIZE],
+};
+static USER_STACK: UserStack = UserStack {
+    data: [0; USER_STACK_SIZE],
+};
+
+impl KernelStack {
+    fn get_sp(&self) -> usize {
+        self.data.as_ptr() as usize + KERNEL_STACK_SIZE
+    }
+
+    pub fn push_context(&self, cx: TrapContext) -> &'static mut TrapContext {
+        let cx_ptr = (self.get_sp() - mem::size_of::<TrapContext>()) as *mut TrapContext;
+        unsafe {
+            *cx_ptr = cx;
+        }
+        unsafe { cx_ptr.as_mut().unwrap() }
+    }
+}
+
+impl UserStack {
+    fn get_sp(&self) -> usize {
+        self.data.as_ptr() as usize + USER_STACK_SIZE
+    }
+}
+
+struct AppManager {
+    num_app: usize,
+    current_app: usize,
+    app_start: [usize; MAX_APP_NUM + 1],
+}
+
+impl AppManager {
+    pub fn print_app_info(&self) {
+        info!(target: "kernel", "num_app = {}", self.num_app);
+        for i in 0..self.num_app {
+            info!(target: "kernel", "app_{} [{:#x}, {:#x}]", i, self.app_start[i], self.app_start[i + 1]);
+        }
+    }
+
+    pub fn get_current_app(&self) -> usize {
+        self.current_app
+    }
+
+    pub fn move_to_next_app(&mut self) {
+        self.current_app += 1;
+    }
+
+    unsafe fn load_app(&self, app_id: usize) {
+        if app_id >= self.num_app {
+            info!(target: "kernel", "All applications completed");
+            shutdown(false);
+        }
+        info!(target: "kernel", "Loading app_{}", app_id);
+
+        slice::from_raw_parts_mut(APP_BASE_ADDRESS as *mut u8, APP_SIZE_LIMIT).fill(0);
+        let app_src = slice::from_raw_parts(self.app_start[app_id] as *const u8, self.app_start[app_id + 1] - self.app_start[app_id]);
+        let app_dst = slice::from_raw_parts_mut(APP_BASE_ADDRESS as *mut u8, app_src.len());
+        app_dst.copy_from_slice(app_src);
+        asm!("fence.i");
+    }
+}
+
+lazy_static! {
+    static ref APP_MANAGER: UPSafeCell<AppManager> = unsafe {
+        UPSafeCell::new({
+            extern "C" {
+                fn _num_app();
+            }
+
+            let num_app_ptr = _num_app as usize as *const usize;
+            let num_app = num_app_ptr.read_volatile();
+            let mut app_start: [usize; MAX_APP_NUM + 1] = [0; MAX_APP_NUM + 1];
+            let app_start_raw: &[usize] = slice::from_raw_parts(num_app_ptr.add(1), num_app + 1);
+            app_start[..=num_app].copy_from_slice(app_start_raw);
+            AppManager {
+                num_app,
+                current_app: 0,
+                app_start,
+            }
+        })
+    };
+}
+
+pub fn init() {
+    print_app_info();
+}
+
+pub fn print_app_info() {
+    APP_MANAGER.exclusive_access().print_app_info();
+}
+
+pub fn run_next_app() -> ! {
+    let mut app_manager = APP_MANAGER.exclusive_access();
+    let current_app = app_manager.get_current_app();
+    unsafe {
+        app_manager.load_app(current_app);
+    }
+    app_manager.move_to_next_app();
+    drop(app_manager);
+
+    extern "C" {
+        fn __restore(cx_addr: usize);
+    }
+    unsafe {
+        __restore(KERNEL_STACK.push_context(TrapContext::app_init_context(
+            APP_BASE_ADDRESS,
+            USER_STACK.get_sp(),
+        )) as *const _ as usize);
+    }
+    panic!("Unreachable in batch::run_current_app");
+}

os/src/lang_items.rs

@@ -3,15 +3,16 @@ use crate::{sbi, println};
 
 #[panic_handler]
 fn panic(info: &PanicInfo) -> ! {
+    let err = info.message().as_str().unwrap();
     if let Some(location) = info.location() {
         println!(
             "Panicked at {}:{} {}",
             location.file(),
             location.line(),
-            info.message().as_str().unwrap()
+            err
         );
     } else {
-        println!("Panicked: {}", info.message().as_str().unwrap());
+        println!("Panicked: {}", err);
     }
     sbi::shutdown(true)
 }

os/src/link_app.S

@@ -0,0 +1,47 @@
+
+    .align 3
+    .section .data
+    .global _num_app
+_num_app:
+    .quad 5
+    .quad app_0_start
+    .quad app_1_start
+    .quad app_2_start
+    .quad app_3_start
+    .quad app_4_start
+    .quad app_4_end
+
+    .section .data
+    .global app_0_start
+    .global app_0_end
+app_0_start:
+    .incbin "../user/target/riscv64gc-unknown-none-elf/release/00_hello_world.bin"
+app_0_end:
+
+    .section .data
+    .global app_1_start
+    .global app_1_end
+app_1_start:
+    .incbin "../user/target/riscv64gc-unknown-none-elf/release/01_store_fault.bin"
+app_1_end:
+
+    .section .data
+    .global app_2_start
+    .global app_2_end
+app_2_start:
+    .incbin "../user/target/riscv64gc-unknown-none-elf/release/02_power.bin"
+app_2_end:
+
+    .section .data
+    .global app_3_start
+    .global app_3_end
+app_3_start:
+    .incbin "../user/target/riscv64gc-unknown-none-elf/release/03_priv_inst.bin"
+app_3_end:
+
+    .section .data
+    .global app_4_start
+    .global app_4_end
+app_4_start:
+    .incbin "../user/target/riscv64gc-unknown-none-elf/release/04_priv_csr.bin"
+app_4_end:

os/src/main.rs

@@ -8,10 +8,16 @@ mod logger;
 #[macro_use]
 mod console;
 
+mod batch;
+mod sync;
+mod trap;
+mod syscall;
+
 use core::arch::global_asm;
 use log::{debug, error, info, trace, warn};
 
 global_asm!(include_str!("entry.asm"));
+global_asm!(include_str!("link_app.S"));
 
 #[no_mangle]
 pub fn rust_main() -> ! {
@@ -21,7 +27,9 @@ pub fn rust_main() -> ! {
     print_system_info();
     print_to_console();
 
-    panic!("Shutdown machine!");
+    trap::init();
+    batch::init();
+    batch::run_next_app();
 }
 
 fn clear_bss() {

os/src/sync/mod.rs

@@ -0,0 +1,3 @@
+mod up;
+
+pub use up::UPSafeCell;

os/src/sync/up.rs

@@ -0,0 +1,18 @@
+use core::cell::{RefCell, RefMut};
+
+pub struct  UPSafeCell<T> {
+    inner: RefCell<T>
+}
+
+unsafe impl <T> Sync for UPSafeCell<T> {}
+
+impl<T> UPSafeCell<T> {
+    pub unsafe fn new(value: T) -> Self {
+        Self {
+            inner: RefCell::new(value)
+        }
+    }
+    pub fn exclusive_access(&self) -> RefMut<'_, T> {
+        self.inner.borrow_mut()
+    }
+}

os/src/syscall/fs.rs

@@ -0,0 +1,17 @@
+use core::{slice, str};
+
+const FD_STDOUT: usize = 1;
+
+pub fn sys_write(fd: usize, buf: *const u8, len: usize) -> isize {
+    match fd {
+        FD_STDOUT => {
+            let slice = unsafe { slice::from_raw_parts(buf, len) };
+            let str = str::from_utf8(slice).unwrap();
+            print!("{}", str);
+            len as isize
+        }
+        _ => {
+            panic!("Unsupported fd in sys_write!");
+        }
+    }
+}

os/src/syscall/mod.rs

@@ -0,0 +1,16 @@
+use fs::sys_write;
+use process::sys_exit;
+
+const SYSCALL_WRITE: usize = 64;
+const SYSCALL_EXIT: usize = 93;
+
+mod fs;
+mod process;
+
+pub fn syscall(syscall_id: usize, args: [usize; 3]) -> isize {
+    match syscall_id {
+        SYSCALL_WRITE => sys_write(args[0], args[1] as *const u8, args[2]),
+        SYSCALL_EXIT => sys_exit(args[0] as i32),
+        _ => panic!("Unsupported syscall_id: {}", syscall_id)
+    }
+}

os/src/syscall/process.rs

@@ -0,0 +1,8 @@
+use log::info;
+
+use crate::batch::run_next_app;
+
+pub fn sys_exit(exit_code: i32) -> ! {
+    info!(target: "kernel", "Application exited with code {}", exit_code);
+    run_next_app()
+}

os/src/trap/context.rs

@@ -0,0 +1,28 @@
+use riscv::register::sstatus::{self, Sstatus, SPP};
+
+#[repr(C)]
+pub struct TrapContext {
+    pub x: [usize; 32],
+    pub sstatus: Sstatus,
+    pub sepc: usize,
+}
+
+impl TrapContext {
+    pub fn set_sp(&mut self, sp: usize) {
+        self.x[2] = sp;
+    }
+
+    pub fn app_init_context(entry: usize, sp: usize) -> Self {
+        let cur_sstatus = sstatus::read();
+        unsafe {
+            sstatus::set_spp(SPP::User);
+        }
+        let mut cx = Self {
+            x: [0; 32],
+            sstatus: cur_sstatus,
+            sepc: entry,
+        };
+        cx.set_sp(sp);
+        cx
+    }
+}

os/src/trap/mod.rs

@@ -0,0 +1,44 @@
+mod context;
+pub use context::TrapContext;
+use log::error;
+
+use core::arch::global_asm;
+
+use riscv::{interrupt::{Exception, Trap}, register::{scause, stval, stvec::{self, TrapMode}}};
+
+use crate::{batch::run_next_app, syscall};
+
+global_asm!(include_str!("trap.S"));
+
+pub fn init() {
+    extern "C" {
+        fn __alltraps();
+    }
+    unsafe {
+        stvec::write(__alltraps as usize, TrapMode::Direct);
+    }
+}
+
+#[no_mangle]
+pub fn trap_handler(cx: &mut TrapContext) -> &mut TrapContext {
+    let scause = scause::read();
+    let stval = stval::read();
+    match scause.cause() {
+        Trap::Exception(e) if e == Exception::UserEnvCall as usize => {
+            cx.sepc += 4;
+            cx.x[10] = syscall::syscall(cx.x[17], [cx.x[10], cx.x[11], cx.x[12]]) as usize;
+        }
+        Trap::Exception(e) if e == Exception::StoreFault as usize || e == Exception::StorePageFault as usize => {
+            error!(target: "kernel", "PageFault in application, kernel killed it.");
+            run_next_app();
+        }
+        Trap::Exception(e) if e == Exception::IllegalInstruction as usize => {
+            error!(target: "kernel", "IllegalInstruction in application, kernel killed it.");
+            run_next_app();
+        }
+        _ => {
+            panic!("un supported strp {:?}, stval = {:#x}!", scause.cause(), stval);
+        }
+    }
+    cx
+}

os/src/trap/trap.S

@@ -0,0 +1,64 @@
+.altmacro
+.macro SAVE_GP n
+    sd x\n, \n*8(sp)
+.endm
+.macro LOAD_GP n
+    ld x\n, \n*8(sp)
+.endm
+    .section .text
+    .globl __alltraps
+    .globl __restore
+    .align 2
+__alltraps:
+    csrrw sp, sscratch, sp
+    # now sp->kernel stack, sscratch->user stack
+    # allocate a TrapContext on kernel stack
+    addi sp, sp, -34*8
+    # save general-purpose registers
+    sd x1, 1*8(sp)
+    # skip sp(x2), we will save it later
+    sd x3, 3*8(sp)
+    # skip tp(x4), application does not use it
+    # save x5~x31
+    .set n, 5
+    .rept 27
+        SAVE_GP %n
+        .set n, n+1
+    .endr
+    # we can use t0/t1/t2 freely, because they were saved on kernel stack
+    csrr t0, sstatus
+    csrr t1, sepc
+    sd t0, 32*8(sp)
+    sd t1, 33*8(sp)
+    # read user stack from sscratch and save it on the kernel stack
+    csrr t2, sscratch
+    sd t2, 2*8(sp)
+    # set input argument of trap_handler(cx: &mut TrapContext)
+    mv a0, sp
+    call trap_handler
+
+__restore:
+    # case1: start running app by __restore
+    # case2: back to U after handling trap
+    mv sp, a0
+    # now sp->kernel stack(after allocated), sscratch->user stack
+    # restore sstatus/sepc
+    ld t0, 32*8(sp)
+    ld t1, 33*8(sp)
+    ld t2, 2*8(sp)
+    csrw sstatus, t0
+    csrw sepc, t1
+    csrw sscratch, t2
+    # restore general-purpuse registers except sp/tp
+    ld x1, 1*8(sp)
+    ld x3, 3*8(sp)
+    .set n, 5
+    .rept 27
+        LOAD_GP %n
+        .set n, n+1
+    .endr
+    # release TrapContext on kernel stack
+    addi sp, sp, 34*8
+    # now sp->kernel stack, sscratch->user stack
+    csrrw sp, sscratch, sp
+    sret

user/.cargo/config.toml

@@ -0,0 +1,7 @@
+[build]
+target = "riscv64gc-unknown-none-elf"
+
+[target.riscv64gc-unknown-none-elf]
+rustflags = [
+    "-Clink-arg=-Tsrc/linker.ld", "-Cforce-frame-pointers=yes"
+]

user/.gitignore

@@ -0,0 +1 @@
+/target

user/Cargo.lock

@@ -0,0 +1,93 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "critical-section"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "790eea4361631c5e7d22598ecd5723ff611904e3344ce8720784c93e3d83d40b"
+
+[[package]]
+name = "embedded-hal"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "361a90feb7004eca4019fb28352a9465666b24f840f5c3cddf0ff13920590b89"
+
+[[package]]
+name = "paste"
+version = "1.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.89"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f139b0662de085916d1fb67d2b4169d1addddda1919e696f3252b740b629986e"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5b9d34b8991d19d98081b46eacdd8eb58c6f2b201139f7c5f643cc155a633af"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "riscv"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ea8ff73d3720bdd0a97925f0bf79ad2744b6da8ff36be3840c48ac81191d7a7"
+dependencies = [
+ "critical-section",
+ "embedded-hal",
+ "paste",
+ "riscv-macros",
+ "riscv-pac",
+]
+
+[[package]]
+name = "riscv-macros"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f265be5d634272320a7de94cea15c22a3bfdd4eb42eb43edc528415f066a1f25"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "riscv-pac"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8188909339ccc0c68cfb5a04648313f09621e8b87dc03095454f1a11f6c5d436"
+
+[[package]]
+name = "syn"
+version = "2.0.87"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "25aa4ce346d03a6dcd68dd8b4010bcb74e54e62c90c573f394c46eae99aba32d"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e91b56cd4cadaeb79bbf1a5645f6b4f8dc5bde8834ad5894a8db35fda9efa1fe"
+
+[[package]]
+name = "user_lib"
+version = "0.1.0"
+dependencies = [
+ "riscv",
+]

user/Cargo.toml

@@ -1,8 +1,7 @@
 [package]
-name = "os"
+name = "user_lib"
 version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-log = "0.4.22"
-sbi-rt = "0.0.3"
+riscv = "0.12.1"

user/src/bin/00_hello_world.rs

@@ -0,0 +1,11 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+#[no_mangle]
+fn main() -> i32 {
+    println!("Hello, world!");
+    0
+}

user/src/bin/01_store_fault.rs

@@ -0,0 +1,15 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+#[no_mangle]
+fn main() -> i32 {
+    println!("Into Test store_fault, we will insert an invalid store operation...");
+    println!("kerne; should kill this application");
+    unsafe  {
+        core::ptr::null_mut::<u8>().write_volatile(0);
+    }
+    0
+}

user/src/bin/02_power.rs

@@ -0,0 +1,27 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+const SIZE: usize = 10;
+const P: u32 = 3;
+const STEP: usize = 100000;
+const MOD: u32 = 10007;
+
+#[no_mangle]
+fn main() -> i32 {
+    let mut pow = [0u32; SIZE];
+    let mut index: usize = 0;
+    pow[index] = 1;
+    for i in 1..=STEP {
+        let last = pow[index];
+        index = (index + 1) % SIZE;
+        pow[index] = last * P % MOD;
+        if i % 10000 == 0 {
+            println!("{}^{}={}(MOD {})", P, i, pow[index], MOD);
+        }
+    }
+    println!("Test power OK!");
+    0
+}

user/src/bin/03_priv_inst.rs

@@ -0,0 +1,17 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use core::arch::asm;
+
+#[no_mangle]
+fn main() -> i32 {
+    println!("Try to execute privileged instruction in U Mode");
+    println!("Kernel should kill this application!");
+    unsafe {
+        asm!("sret");
+    }
+    0
+}

user/src/bin/04_priv_csr.rs

@@ -0,0 +1,17 @@
+#![no_std]
+#![no_main]
+
+#[macro_use]
+extern crate user_lib;
+
+use riscv::register::sstatus::{self, SPP};
+
+#[no_mangle]
+fn main() -> i32 {
+    println!("Try to access privileged CSR in U Mode");
+    println!("Kernel should kill this application!");
+    unsafe {
+        sstatus::set_spp(SPP::User);
+    }
+    0
+}

user/src/console.rs

@@ -0,0 +1,32 @@
+use super::write;
+use core::fmt::{self, Write};
+
+
+struct Stdout;
+
+const STDOUT: usize = 1;
+
+impl Write for Stdout {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        write(STDOUT, s.as_bytes());
+        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)+)?));
+    }
+}

user/src/lang_items.rs

@@ -0,0 +1,17 @@
+use core::panic::PanicInfo;
+
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    let err = info.message().as_str().unwrap();
+    if let Some(location) = info.location() {
+        println!(
+            "Panicked at {}:{}, {}",
+            location.file(),
+            location.line(),
+            err
+        );
+    } else {
+        println!("Panicked: {}", err);
+    }
+    loop {}
+}

user/src/lib.rs

@@ -0,0 +1,38 @@
+#![no_std]
+
+#[macro_use]
+pub mod console;
+mod syscall;
+mod lang_items;
+
+#[no_mangle]
+#[link_section = ".text.entry"]
+pub extern "C" fn _start() -> ! {
+    // linkage is not stable
+    // but main function in user function required
+    extern "C" {
+        fn main() -> i32;
+    }
+    clear_bss();
+    unsafe {
+        exit(main());
+    }
+    panic!("unreachable after sys_exit")
+}
+
+fn clear_bss() {
+    extern "C" {
+        fn sbss();
+        fn ebss();
+    }
+    (sbss as usize..ebss as usize).for_each(|addr| unsafe {
+        (addr as *mut u8).write_volatile(0);
+    });
+}
+
+pub fn write(fd: usize, buf: &[u8]) -> isize {
+    syscall::sys_write(fd, buf)
+}
+pub fn exit(exit_code: i32) -> isize {
+    syscall::sys_exit(exit_code)
+}

user/src/linker.ld

@@ -0,0 +1,46 @@
+OUTPUT_ARCH(riscv)
+ENTRY(_start)
+BASE_ADDRESS = 0x80400000;
+
+SECTIONS
+{
+    . = BASE_ADDRESS;
+
+    stext = .;
+    .text : {
+        *(.text.entry)
+        *(.text .text.*)
+    }
+
+    . = ALIGN(4K);
+    etext = .;
+    srodata = .;
+    .rodata : {
+        *(.data .rodata.*)
+        *(.srodata .srodata.*)
+    }
+
+    . = ALIGN(4K);
+    erodata = .;
+    sdata = .;
+    .data : {
+        *(.data .data.*)
+        *(.sdata .sdata.*)
+    }
+
+    . = ALIGN(4K);
+    edata = .;
+    .bss : {
+        *(.bss.stack)
+        sbss = .;
+        *(.bss .bss.*)
+        *(.sbss .sbss.*)
+    }
+
+    . = ALIGN(4K);
+    ebss = .;
+     
+    /DISCARD/ : {
+        *(.eh_frame)
+    }
+}

user/src/syscall.rs

@@ -0,0 +1,26 @@
+use core::arch::asm;
+
+const SYSCALL_WRITE: usize = 64;
+const SYSCALL_EXIT: usize = 93;
+
+fn syscall(id: usize, args: [usize; 3]) -> isize {
+    let mut ret: isize;
+    unsafe {
+        asm!(
+            "ecall",
+            inlateout("x10") args[0] => ret,
+            in("x11") args[1],
+            in("x12") args[2],
+            in("x17") id
+        );
+    }
+    ret
+}
+
+pub fn sys_write(fd: usize, buffer: &[u8]) -> isize {
+    syscall(SYSCALL_WRITE, [fd, buffer.as_ptr() as usize, buffer.len()])
+}
+
+pub fn sys_exit(exit_code: i32) -> isize {
+    syscall(SYSCALL_EXIT, [exit_code as usize, 0, 0])
+}