2 files changed, 127 insertions, 1 deletions
diff --git a/vendor/dlmalloc/src/lib.rs b/vendor/dlmalloc/src/lib.rs
index 238386fbc..b972ccb73 100644
--- a/vendor/dlmalloc/src/lib.rs
+++ b/vendor/dlmalloc/src/lib.rs
@@ -81,7 +81,16 @@ mod sys;
 #[path = "unix.rs"]
 mod sys;
 
-#[cfg(not(any(target_os = "linux", target_os = "macos", target_family = "wasm")))]
+#[cfg(target_os = "xous")]
+#[path = "xous.rs"]
+mod sys;
+
+#[cfg(not(any(
+    target_os = "linux",
+    target_os = "macos",
+    target_os = "xous",
+    target_family = "wasm"
+)))]
 #[path = "dummy.rs"]
 mod sys;
 
diff --git a/vendor/dlmalloc/src/xous.rs b/vendor/dlmalloc/src/xous.rs
new file mode 100644
index 000000000..96cb4e0d3
--- /dev/null
+++ b/vendor/dlmalloc/src/xous.rs
@@ -0,0 +1,117 @@
+use core::ptr;
+use Allocator;
+
+pub struct System {
+    _priv: (),
+}
+
+impl System {
+    pub const fn new() -> System {
+        System { _priv: () }
+    }
+}
+
+#[cfg(target_arch = "riscv32")]
+mod sys {
+    use core::arch::asm;
+
+    pub fn increase_heap(length: usize) -> Result<(usize, usize), ()> {
+        let syscall_no_increase_heap = 10usize;
+        let memory_flags_read_write = 2usize | 4usize;
+
+        let mut a0 = syscall_no_increase_heap;
+        let mut a1 = length;
+        let mut a2 = memory_flags_read_write;
+
+        unsafe {
+            asm!(
+                "ecall",
+                inlateout("a0") a0,
+                inlateout("a1") a1,
+                inlateout("a2") a2,
+                out("a3") _,
+                out("a4") _,
+                out("a5") _,
+                out("a6") _,
+                out("a7") _,
+            )
+        };
+
+        let result = a0;
+        let address = a1;
+        let length = a2;
+
+        // 3 is the "MemoryRange" type, and the result is only valid
+        // if we get nonzero address and length.
+        if result == 3 && address != 0 && length != 0 {
+            Ok((address, length))
+        } else {
+            Err(())
+        }
+    }
+}
+
+unsafe impl Allocator for System {
+    /// Allocate an additional `size` bytes on the heap, and return a new
+    /// chunk of memory, as well as the size of the allocation and some
+    /// flags. Since flags are unused on this platform, they will always
+    /// be `0`.
+    fn alloc(&self, size: usize) -> (*mut u8, usize, u32) {
+        let size = if size == 0 {
+            4096
+        } else if size & 4095 == 0 {
+            size
+        } else {
+            size + (4096 - (size & 4095))
+        };
+
+        if let Ok((address, length)) = sys::increase_heap(size) {
+            let start = address - size + length;
+            (start as *mut u8, size, 0)
+        } else {
+            (ptr::null_mut(), 0, 0)
+        }
+    }
+
+    fn remap(&self, _ptr: *mut u8, _oldsize: usize, _newsize: usize, _can_move: bool) -> *mut u8 {
+        // TODO
+        ptr::null_mut()
+    }
+
+    fn free_part(&self, _ptr: *mut u8, _oldsize: usize, _newsize: usize) -> bool {
+        false
+    }
+
+    fn free(&self, _ptr: *mut u8, _size: usize) -> bool {
+        false
+    }
+
+    fn can_release_part(&self, _flags: u32) -> bool {
+        false
+    }
+
+    fn allocates_zeros(&self) -> bool {
+        true
+    }
+
+    fn page_size(&self) -> usize {
+        4 * 1024
+    }
+}
+
+#[cfg(feature = "global")]
+pub fn acquire_global_lock() {
+    // global feature should not be enabled
+    unimplemented!()
+}
+
+#[cfg(feature = "global")]
+pub fn release_global_lock() {
+    // global feature should not be enabled
+    unimplemented!()
+}
+
+#[cfg(feature = "global")]
+pub unsafe fn enable_alloc_after_fork() {
+    // platform does not support `fork()` call
+}