wutnewlib: Allow custom fixed sbrk heap size.

So now either uses 90% of the available base heap, or allocates a fixed
sized heap from the default heap.

libraries/wutnewlib/CMakeLists.txt

@@ -5,7 +5,6 @@ add_library(wutnewlib
    wut_clock.c
    wut_gettod_r.c
    wut_lock.c
-   wut_malloc.c
    wut_malloc_lock.c
    wut_nanosleep.c
    wut_newlib.c

libraries/wutnewlib/wut_malloc.c

@@ -1,88 +0,0 @@
-#include <coreinit/memexpheap.h>
-#include <coreinit/memdefaultheap.h>
-#include <coreinit/memorymap.h>
-#include <malloc.h>
-#include <string.h>
-
-void *
-_malloc_r(struct _reent *r, size_t size)
-{
-   return MEMAllocFromDefaultHeap(size);
-}
-
-void
-_free_r(struct _reent *r, void *ptr)
-{
-   MEMFreeToDefaultHeap(ptr);
-}
-
-void *
-_realloc_r(struct _reent *r, void *ptr, size_t size)
-{
-   void *new_ptr = _malloc_r(r, size);
-   if (!ptr || !new_ptr) {
-      return new_ptr;
-   }
-
-   memcpy(new_ptr, ptr, MEMGetSizeForMBlockExpHeap(ptr));
-   _free_r(r, ptr);
-   return new_ptr;
-}
-
-void *
-_calloc_r(struct _reent *r, size_t num, size_t size)
-{
-   void *ptr = _malloc_r(r, num * size);
-   if (ptr) {
-      memset(ptr, 0, num * size);
-   }
-
-   return ptr;
-}
-
-void *
-_memalign_r(struct _reent *r, size_t align, size_t size)
-{
-   return MEMAllocFromDefaultHeapEx(size, align);
-}
-
-struct mallinfo _mallinfo_r(struct _reent *r)
-{
-   struct mallinfo info = { 0 };
-   return info;
-}
-
-void
-_malloc_stats_r(struct _reent *r)
-{
-}
-
-int
-_mallopt_r(struct _reent *r, int param, int value)
-{
-   return 0;
-}
-
-size_t
-_malloc_usable_size_r(struct _reent *r, void *ptr)
-{
-   return MEMGetSizeForMBlockExpHeap(ptr);
-}
-
-void *
-_valloc_r(struct _reent *r, size_t size)
-{
-   return _memalign_r(r, OS_PAGE_SIZE, size);
-}
-
-void *
-_pvalloc_r(struct _reent *r, size_t size)
-{
-   return _memalign_r(r, OS_PAGE_SIZE, (size + (OS_PAGE_SIZE - 1)) & ~(OS_PAGE_SIZE - 1));
-}
-
-int
-_malloc_trim_r(struct _reent *r, size_t pad)
-{
-   return 0;
-}

libraries/wutnewlib/wut_sbrk.c

@@ -1,10 +1,15 @@
 #include "wut_newlib.h"
 
 #include <coreinit/atomic.h>
+#include <coreinit/memheap.h>
 #include <coreinit/memdefaultheap.h>
+#include <coreinit/memexpheap.h>
 
-static uint8_t *sHeapBase = NULL;
-static uint32_t sHeapMaxSize = 128 * 1024;
+extern uint32_t __attribute__((weak)) __wut_heap_max_size;
+
+static MEMHeapHandle sHeapHandle = NULL;
+static void *sHeapBase = NULL;
+static uint32_t sHeapMaxSize = 0;
 static volatile uint32_t sHeapSize = 0;
 
 void *
@@ -23,21 +28,48 @@ __wut_sbrk_r(struct _reent *r,
       }
    } while (!OSCompareAndSwapAtomic(&sHeapSize, oldSize, newSize));
 
-   return sHeapBase + oldSize;
+   return ((uint8_t *)sHeapBase) + oldSize;
 }
 
 void
 __init_wut_sbrk_heap()
 {
-   sHeapMaxSize = 128 * 1024;
-   sHeapBase = (uint8_t *)MEMAllocFromDefaultHeap(sHeapMaxSize);
+   if (sHeapBase) {
+      // Already initialised
+      return;
+   }
+
+   if (__wut_heap_max_size) {
+      // Use default heap
+      sHeapBase = MEMAllocFromDefaultHeap(__wut_heap_max_size);
+      sHeapMaxSize = __wut_heap_max_size;
+   } else {
+      // No max size specified, use 90% of base MEM2 heap
+      sHeapHandle = MEMGetBaseHeapHandle(MEM_BASE_HEAP_MEM2);
+
+      uint32_t freeSize = MEMGetAllocatableSizeForExpHeapEx(sHeapHandle, 4);
+      sHeapMaxSize = (uint32_t)(0.9f * (float)freeSize) & ~0xFFF;
+
+      sHeapBase = MEMAllocFromExpHeapEx(sHeapHandle, sHeapMaxSize, 4);
+   }
+
    sHeapSize = 0;
 }
 
 void
 __fini_wut_sbrk_heap()
 {
-   MEMFreeToDefaultHeap(sHeapBase);
+   if (!sHeapBase) {
+      // Already finalised
+      return;
+   }
+
+   if (sHeapHandle) {
+      MEMFreeToExpHeap(sHeapHandle, sHeapBase);
+   } else {
+      MEMFreeToDefaultHeap(sHeapBase);
+   }
+
    sHeapBase = NULL;
    sHeapSize = 0;
    sHeapMaxSize = 0;