initial commit

lib/kmalloc.c

@@ -0,0 +1,37 @@
+#include <kmalloc.h>
+#include <stddef.h>
+
+extern void *__heap_start;
+extern void *__heap_end;
+
+void *_heap_top = (void *)0;
+
+// simple 8-byte aligned linear allocation
+void *simple_alloc(size_t size)
+{
+  if (!_heap_top) {
+    _heap_top = __heap_start;
+  }
+
+  if (size & 0xff)
+    size = (size & ~0xff) + 0x100;
+  
+  if ((uint64_t)_heap_top + size >= (uint64_t)__heap_end)
+    return (void *)0;
+
+  void *ret = _heap_top;
+  _heap_top = (void *)((uint64_t)_heap_top + size);
+
+  return ret;
+}
+
+void *kmalloc(size_t size)
+{
+  return simple_alloc(size);
+}
+
+void kfree(void *ptr)
+{
+  // not implemented for now
+  return;
+}