1 files changed, 39 insertions, 0 deletions
diff --git a/src/Dolphin/os/OSArena.c b/src/Dolphin/os/OSArena.c
new file mode 100644
index 0000000..da864ab
--- /dev/null
+++ b/src/Dolphin/os/OSArena.c
@@ -0,0 +1,39 @@
+#include <dolphin/os/OSArena.h>
+
+#define ROUND(n, a) (((u32)(n) + (a)-1) & ~((a)-1))
+#define TRUNC(n, a) (((u32)(n)) & ~((a)-1))
+
+void* __OSArenaHi;
+void* __OSArenaLo = (void*)-1;
+
+void* OSGetArenaHi(void) { return __OSArenaHi; }
+
+void* OSGetArenaLo(void) { return __OSArenaLo; }
+
+void OSSetArenaHi(void* addr) { __OSArenaHi = addr; }
+
+void OSSetArenaLo(void* addr) { __OSArenaLo = addr; }
+
+void* OSAllocFromArenaLo(u32 size, u32 align) {
+  void* ptr;
+  u8* arenaLo;
+
+  ptr = OSGetArenaLo();
+  arenaLo = ptr = (void*)ROUND(ptr, align);
+  arenaLo += size;
+  arenaLo = (u8*)ROUND(arenaLo, align);
+  OSSetArenaLo(arenaLo);
+  return ptr;
+}
+
+void* OSAllocFromArenaHi(u32 size, u32 align) {
+  void* ptr;
+  u8* arenaHi;
+
+  arenaHi = OSGetArenaHi();
+  arenaHi = (u8*)TRUNC(arenaHi, align);
+  arenaHi -= size;
+  arenaHi = ptr = (void*)TRUNC(arenaHi, align);
+  OSSetArenaHi(arenaHi);
+  return ptr;
+}