firmware: port allocator to Rust.

artiq/firmware/liballoc_artiq/lib.rs

@@ -1,86 +1,119 @@
-#![feature(allocator, libc)]
+#![allow(dead_code)] // FIXME
+
+#![feature(allocator)]
 #![no_std]
 #![allocator]
 
+use core::{mem, ptr, cmp};
+
 // The minimum alignment guaranteed by the architecture.
-const MIN_ALIGN: usize = 8;
+const MIN_ALIGN: usize = 4;
 
-#[no_mangle]
-pub extern "C" fn __rust_allocate(size: usize, align: usize) -> *mut u8 {
-    unsafe { imp::allocate(size, align) }
-}
+const MAGIC_FREE: usize = 0xDEADDEAD;
+const MAGIC_BUSY: usize = 0xFEEDFEED;
 
-#[no_mangle]
-pub extern "C" fn __rust_deallocate(ptr: *mut u8, old_size: usize, align: usize) {
-    unsafe { imp::deallocate(ptr, old_size, align) }
-}
-
-#[no_mangle]
-pub extern "C" fn __rust_reallocate(ptr: *mut u8,
-                                    old_size: usize,
+#[derive(Debug)]
+struct Header {
+    magic: usize,
     size:  usize,
-                                    align: usize)
-                                    -> *mut u8 {
-    unsafe { imp::reallocate(ptr, old_size, size, align) }
+    next:  *mut Header
+}
+
+static mut ROOT: *mut Header = 0 as *mut _;
+
+pub unsafe fn seed(ptr: *mut u8, size: usize) {
+    let header_size = mem::size_of::<Header>();
+
+    if size < header_size * 2 { return }
+
+    let curr = ptr as *mut Header;
+    (*curr).magic = MAGIC_FREE;
+    (*curr).size  = size - header_size;
+    (*curr).next  = ROOT;
+    ROOT = curr;
 }
 
 #[no_mangle]
-pub extern "C" fn __rust_reallocate_inplace(ptr: *mut u8,
-                                            old_size: usize,
-                                            size: usize,
-                                            align: usize)
-                                            -> usize {
-    unsafe { imp::reallocate_inplace(ptr, old_size, size, align) }
+pub extern fn __rust_allocate(mut size: usize, align: usize) -> *mut u8 {
+    assert!(align <= MIN_ALIGN);
+
+    let header_size = mem::size_of::<Header>();
+    if size % header_size != 0 {
+        size += header_size - (size % header_size);
+    }
+
+    unsafe {
+        let mut curr = ROOT;
+        while !curr.is_null() {
+            match (*curr).magic {
+                MAGIC_BUSY => (),
+                MAGIC_FREE => {
+                    let mut next = (*curr).next;
+                    while !next.is_null() && (*next).magic == MAGIC_FREE {
+                        // Join
+                        (*next).magic = 0;
+                        (*curr).size += (*next).size + header_size;
+                        (*curr).next  = (*next).next;
+                        next = (*curr).next;
+                    }
+
+                    if (*curr).size > size + header_size * 2 {
+                        // Split
+                        let offset = header_size + size;
+                        let next = (curr as *mut u8).offset(offset as isize) as *mut Header;
+                        (*next).magic = MAGIC_FREE;
+                        (*next).size  = (*curr).size - offset;
+                        (*next).next  = (*curr).next;
+                        (*curr).next  = next;
+                        (*curr).size  = size;
+                    }
+
+                    if (*curr).size >= size {
+                        (*curr).magic = MAGIC_BUSY;
+                        return curr.offset(1) as *mut u8
+                    }
+                },
+                _ => panic!("heap corruption detected at {:p}", curr)
+            }
+
+            curr = (*curr).next;
+        }
+    }
+
+    ptr::null_mut()
 }
 
 #[no_mangle]
-pub extern "C" fn __rust_usable_size(size: usize, align: usize) -> usize {
-    imp::usable_size(size, align)
+pub extern fn __rust_deallocate(ptr: *mut u8, _old_size: usize, _align: usize) {
+    unsafe {
+        let curr = (ptr as *mut Header).offset(-1);
+        if (*curr).magic != MAGIC_BUSY {
+            panic!("heap corruption detected at {:p}", curr)
+        }
+        (*curr).magic = MAGIC_FREE;
+    }
 }
 
-mod imp {
-    extern crate libc;
-
-    use core::cmp;
-    use core::ptr;
-    use MIN_ALIGN;
-
-    pub unsafe fn allocate(size: usize, align: usize) -> *mut u8 {
-        if align <= MIN_ALIGN {
-            libc::malloc(size as libc::size_t) as *mut u8
-        } else {
-            aligned_malloc(size, align)
-        }
-    }
-
-    unsafe fn aligned_malloc(_size: usize, _align: usize) -> *mut u8 {
-        panic!("aligned_malloc not implemented")
-    }
-
-    pub unsafe fn reallocate(ptr: *mut u8, old_size: usize,
-                             size: usize, align: usize) -> *mut u8 {
-        if align <= MIN_ALIGN {
-            libc::realloc(ptr as *mut libc::c_void, size as libc::size_t) as *mut u8
-        } else {
-            let new_ptr = allocate(size, align);
+#[no_mangle]
+pub extern fn __rust_reallocate(ptr: *mut u8, old_size: usize, size: usize,
+                                align: usize) -> *mut u8 {
+    unsafe {
+        let new_ptr = __rust_allocate(size, align);
         if !new_ptr.is_null() {
-                ptr::copy(ptr, new_ptr, cmp::min(size, old_size));
-                deallocate(ptr, old_size, align);
+            ptr::copy_nonoverlapping(ptr, new_ptr, cmp::min(old_size, size));
+            __rust_deallocate(ptr, old_size, align);
         }
         new_ptr
     }
-    }
-
-    pub unsafe fn reallocate_inplace(_ptr: *mut u8, old_size: usize,
-                                     _size: usize, _align: usize) -> usize {
-        old_size
-    }
-
-    pub unsafe fn deallocate(ptr: *mut u8, _old_size: usize, _align: usize) {
-        libc::free(ptr as *mut libc::c_void)
-    }
-
-    pub fn usable_size(size: usize, _align: usize) -> usize {
-        size
-    }
+}
+
+#[no_mangle]
+pub extern fn __rust_reallocate_inplace(_ptr: *mut u8, old_size: usize, _size: usize,
+                                        _align: usize) -> usize {
+    old_size
+}
+
+#[no_mangle]
+pub extern fn __rust_usable_size(size: usize, _align: usize) -> usize {
+    size
 }

artiq/firmware/runtime/lib.rs

@@ -146,7 +146,6 @@ extern {
     fn uart_init();
     fn uart_isr();
 
-    fn alloc_give(ptr: *mut u8, length: usize);
     static mut _fheap: u8;
     static mut _eheap: u8;
 }
@@ -157,7 +156,7 @@ pub unsafe extern fn main() -> i32 {
     irq::set_ie(true);
     uart_init();
 
-    alloc_give(&mut _fheap as *mut u8,
+    alloc_artiq::seed(&mut _fheap as *mut u8,
                       &_eheap as *const u8 as usize - &_fheap as *const u8 as usize);
 
     static mut LOG_BUFFER: [u8; 65536] = [0; 65536];

artiq/gateware/amp/soc.py

@@ -45,6 +45,8 @@ class AMPSoC:
 
 def build_artiq_soc(soc, argdict):
     builder = Builder(soc, **argdict)
-    builder.add_extra_software_packages()
+    builder.add_software_package("libm")
+    builder.add_software_package("libdyld")
+    builder.add_software_package("libunwind")
     builder.add_software_package("runtime", os.path.join(artiq_dir, "runtime"))
     builder.build()

artiq/gateware/targets/kc705_drtio_satellite.py

@@ -118,7 +118,6 @@ def main():
 
     soc = Satellite(args.config, **soc_kc705_argdict(args))
     builder = Builder(soc, **builder_argdict(args))
-    builder.add_software_package("liballoc")
     builder.add_software_package("satman", os.path.join(artiq_dir, "firmware", "satman"))
     builder.build()
 

artiq/runtime/Makefile

@@ -25,7 +25,6 @@ LDFLAGS += --gc-sections \
 	-L../libcompiler-rt \
 	-L../libbase \
 	-L../libm \
-	-L../liballoc \
 	-L../libunwind \
 	-L../libdyld
 
@@ -44,7 +43,7 @@ runtime.elf: $(RUSTOUT)/libruntime.a ksupport_data.o
 		-T $(RUNTIME_DIRECTORY)/runtime.ld \
 		-o $@ \
 		$^ \
-		-lbase-nofloat -lcompiler-rt -lalloc
+		-lbase-nofloat -lcompiler-rt
 	@chmod -x $@
 
 .PHONY: $(RUSTOUT_KSUPPORT)/libksupport.a