Try #164:

Author: bors[bot]

.gitignore

@@ -1,3 +1,4 @@
 Cargo.lock
 layout.ld
+platform
 target

Cargo.toml

@@ -6,12 +6,14 @@ license = "MIT/Apache-2.0"
 edition = "2018"
 
 [features]
-alloc = [ "linked_list_allocator" ]
+alloc = ["libtock-core/alloc"]
+custom_panic_handler = ["libtock-core/custom_panic_handler"]
+custom_alloc_error_handler = ["libtock-core/custom_alloc_error_handler"]
 
 [dependencies]
 core = { package = "async-support", path = "async-support" }
+libtock-core = { path = "core" }
 libtock_codegen = { path = "codegen" }
-linked_list_allocator = { optional = true, version = "=0.6.5", default-features = false }
 futures = { version = "0.3.1", default-features = false, features = ["unstable", "cfg-target-has-atomic"] }
 
 [dev-dependencies]
@@ -52,4 +54,5 @@ lto = true
 members = [
     "async-support",
     "codegen",
+    "core"
 ]

core/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "libtock-core"
+version = "0.1.0"
+authors = ["torfmaster <briefe@kebes.de>", "Woyten <woyten.tielesch@online.de>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[features]
+alloc = [ "linked_list_allocator" ]
+custom_panic_handler = []
+custom_alloc_error_handler = []
+
+[dependencies]
+linked_list_allocator = { optional = true, version = "=0.6.5", default-features = false }

core/src/alloc.rs

@@ -0,0 +1,40 @@
+use core::alloc::GlobalAlloc;
+use core::alloc::Layout;
+use core::ptr;
+use core::ptr::NonNull;
+use linked_list_allocator::Heap;
+
+pub static mut HEAP: Heap = Heap::empty();
+
+struct TockAllocator;
+
+unsafe impl GlobalAlloc for TockAllocator {
+    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+        HEAP.allocate_first_fit(layout)
+            .ok()
+            .map_or(ptr::null_mut(), NonNull::as_ptr)
+    }
+
+    unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) {
+        HEAP.deallocate(NonNull::new_unchecked(ptr), layout)
+    }
+}
+
+#[global_allocator]
+static ALLOCATOR: TockAllocator = TockAllocator;
+
+#[cfg(not(feature = "custom_alloc_error_handler"))]
+#[alloc_error_handler]
+unsafe fn alloc_error_handler(_: Layout) -> ! {
+    use crate::syscalls;
+
+    // Print 0x01 using the LowLevelDebug capsule (if available).
+    let _ = syscalls::command1_insecure(8, 2, 0x01);
+
+    // Signal a panic using the LowLevelDebug capsule (if available).
+    let _ = syscalls::command1_insecure(8, 1, 0x01);
+
+    loop {
+        syscalls::raw::yieldk();
+    }
+}

src/callback.rs renamed to core/src/callback.rs

@@ -0,0 +1,5 @@
+#[cfg_attr(target_arch = "arm", path = "platform_arm.rs")]
+#[cfg_attr(target_arch = "riscv32", path = "platform_riscv32.rs")]
+mod platform;
+
+pub use platform::*;

core/src/debug/mod.rs

@@ -0,0 +1,3 @@
+pub fn get_stack_pointer() -> usize {
+    panic!("Not implemented yet")
+}

core/src/debug/platform.rs

@@ -0,0 +1,5 @@
+pub fn get_stack_pointer() -> usize {
+    let stack_pointer;
+    unsafe { asm!("mov $0, sp" : "=r"(stack_pointer) : : : "volatile") };
+    stack_pointer
+}

core/src/debug/platform_arm.rs

@@ -0,0 +1,5 @@
+pub fn get_stack_pointer() -> usize {
+    let stack_pointer;
+    unsafe { asm!("mv $0, sp" : "=r"(stack_pointer) : : : "volatile") };
+    stack_pointer
+}

core/src/debug/platform_riscv32.rs

@@ -57,10 +57,6 @@ use core::ptr;
 
 #[cfg_attr(target_arch = "riscv32", path = "start_item_riscv32.rs")]
 #[cfg_attr(target_arch = "arm", path = "start_item_arm.rs")]
-#[cfg_attr(
-    not(any(target_arch = "arm", target_arch = "riscv32")),
-    path = "start_item_mock.rs"
-)]
 mod start_item;
 
 /// The header encoded at the beginning of .text by the linker script. It is