Heap test passed on k210/qemu, heap size = 3M.

os/Cargo.lock

@@ -30,13 +30,22 @@ version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
 
+[[package]]
+name = "buddy_system_allocator"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b4e85e760e105b46ae0bd1236578793c6c147ae7463fe95c8350296b8bfcb830"
+dependencies = [
+ "spin 0.7.0",
+]
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 dependencies = [
- "spin",
+ "spin 0.5.2",
 ]
 
 [[package]]
@@ -49,6 +58,7 @@ checksum = "0ee1c47aaa256ecabcaea351eae4a9b01ef39ed810004e298d2511ed284b1525"
 name = "os"
 version = "0.1.0"
 dependencies = [
+ "buddy_system_allocator",
  "lazy_static",
  "riscv",
 ]
@@ -122,6 +132,12 @@ version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
 
+[[package]]
+name = "spin"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "652ac3743312871a5fb703f0337e68ffa3cdc28c863efad0b8dc858fa10c991b"
+
 [[package]]
 name = "thread_local"
 version = "1.0.1"

os/Cargo.toml

@@ -9,6 +9,7 @@ edition = "2018"
 [dependencies]
 riscv = { git = "https://github.com/rcore-os/riscv", features = ["inline-asm"] }
 lazy_static = { version = "1.4.0", features = ["spin_no_std"] }
+buddy_system_allocator = "0.6"
 
 [features]
 board_qemu = []

os/build.rs

@@ -6,7 +6,7 @@ fn main() {
     insert_app_data().unwrap();
 }
 
-static TARGET_PATH: &str = "../user/target/riscv64gc-unknown-none-elf/debug/";
+static TARGET_PATH: &str = "../user/target/riscv64gc-unknown-none-elf/release/";
 
 fn insert_app_data() -> Result<()> {
     let mut f = File::create("src/link_app.S").unwrap();
@@ -26,17 +26,14 @@ fn insert_app_data() -> Result<()> {
     .section .data
     .global _num_app
 _num_app:
-    .quad {}
+    .quad {}"#, apps.len())?;
-    "#, apps.len())?;
 
     for i in 0..apps.len() {
         writeln!(f, r#"
-    .quad app_{}_start
+    .quad app_{}_start"#, i)?;
-        "#, i)?;
     }
     writeln!(f, r#"
-    .quad app_{}_end
+    .quad app_{}_end"#, apps.len() - 1)?;
-    "#, apps.len() - 1)?;
 
     for (idx, app) in apps.iter().enumerate() {
         println!("app_{}: {}", idx, app);
@@ -45,9 +42,8 @@ _num_app:
     .global app_{0}_start
     .global app_{0}_end
 app_{0}_start:
-    .incbin "{2}{1}.bin"
+    .incbin "{2}{1}"
-app_{0}_end:
+app_{0}_end:"#, idx, app, TARGET_PATH)?;
-        "#, idx, app, TARGET_PATH)?;
     }
     Ok(())
 }

os/src/config.rs

@@ -3,6 +3,7 @@ pub const KERNEL_STACK_SIZE: usize = 4096 * 2;
 pub const MAX_APP_NUM: usize = 4;
 pub const APP_BASE_ADDRESS: usize = 0x80100000;
 pub const APP_SIZE_LIMIT: usize = 0x20000;
+pub const KERNEL_HEAP_SIZE: usize = 0x30_0000;
 
 #[cfg(feature = "board_k210")]
 pub const CPU_FREQ: usize = 10000000;

os/src/main.rs

@@ -4,6 +4,9 @@
 #![feature(llvm_asm)]
 #![feature(panic_info_message)]
 #![feature(const_in_array_repeat_expressions)]
+#![feature(alloc_error_handler)]
+
+extern crate alloc;
 
 #[macro_use]
 mod console;
@@ -15,6 +18,7 @@ mod loader;
 mod config;
 mod task;
 mod timer;
+mod mm;
 
 global_asm!(include_str!("entry.asm"));
 global_asm!(include_str!("link_app.S"));
@@ -33,6 +37,9 @@ fn clear_bss() {
 pub fn rust_main() -> ! {
     clear_bss();
     println!("[kernel] Hello, world!");
+    mm::init_heap();
+    mm::heap_test();
+    loop {}
     trap::init();
     loader::load_apps();
     trap::enable_interrupt();

os/src/mm/heap_allocator.rs

@@ -0,0 +1,45 @@
+use buddy_system_allocator::LockedHeap;
+use crate::config::KERNEL_HEAP_SIZE;
+
+#[global_allocator]
+static HEAP_ALLOCATOR: LockedHeap = LockedHeap::empty();
+
+#[alloc_error_handler]
+pub fn handle_alloc_error(layout: core::alloc::Layout) -> ! {
+    panic!("Heap allocation error, layout = {:?}", layout);
+}
+
+static mut HEAP_SPACE: [u8; KERNEL_HEAP_SIZE] = [0; KERNEL_HEAP_SIZE];
+
+pub fn init_heap() {
+    unsafe {
+        HEAP_ALLOCATOR
+            .lock()
+            .init(HEAP_SPACE.as_ptr() as usize, KERNEL_HEAP_SIZE);
+    }
+}
+
+#[allow(unused)]
+pub fn heap_test() {
+    use alloc::boxed::Box;
+    use alloc::vec::Vec;
+    extern "C" {
+        fn sbss();
+        fn ebss();
+    }
+    let bss_range = sbss as usize..ebss as usize;
+    let a = Box::new(5);
+    assert_eq!(*a, 5);
+    assert!(bss_range.contains(&(a.as_ref() as *const _ as usize)));
+    drop(a);
+    let mut v: Vec<usize> = Vec::new();
+    for i in 0..500 {
+        v.push(i);
+    }
+    for i in 0..500 {
+        assert_eq!(v[i], i);
+    }
+    assert!(bss_range.contains(&(v.as_ptr() as usize)));
+    drop(v);
+    println!("heap_test passed!");
+}

os/src/mm/mod.rs

@@ -0,0 +1,4 @@
+mod heap_allocator;
+
+pub use heap_allocator::init_heap;
+pub use heap_allocator::heap_test;