first commit

src/memory.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include "src/panic.h"
+#include <stdint.h>
+
+void memory_init();
+
+void *memory_allocate(uint64_t size);
+
+void memory_free(void *pointer);
+
+static inline void memory_set(uint8_t value, uint64_t bytes, void *to) {
+  __asm__ volatile("rep stosb" : "=D"(to), "=c"(bytes) : "D"(to), "a"(value), "c"(bytes) : "memory");
+}
+
+static inline void memory_move(void *from, uint64_t bytes, void *to) {
+  if (to == from) {
+    return;
+  } else if (to < from) {
+    __asm__ volatile("rep movsb" : "=D"(to), "=S"(from), "=c"(bytes) : "D"(to), "S"(from), "c"(bytes) : "memory");
+  } else {
+    ASSERT(0, "memory_move: forward overlapping move not implemented");
+  }
+}
+
+static inline void memory_copy(const void *from, uint64_t bytes, void *to) {
+  ASSERT((uint64_t)to + bytes <= (uint64_t)from || (uint64_t)to >= (uint64_t)from + bytes, "memory_copy: overlapping backward copy");
+
+  __asm__ volatile("rep movsb" : "=D"(to), "=S"(from), "=c"(bytes) : "D"(to), "S"(from), "c"(bytes) : "memory");
+}