1 files changed, 146 insertions, 0 deletions
diff --git a/riscv/riscv-probe/libfemto/std/malloc.c b/riscv/riscv-probe/libfemto/std/malloc.c
new file mode 100644
index 0000000..3df26f3
--- /dev/null
+++ b/riscv/riscv-probe/libfemto/std/malloc.c
@@ -0,0 +1,146 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 Embedded Artistry
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "list.h"
+
+/* align to nearest power of two */
+#define ALIGN_SIZE(sz, align) (((sz) + ((align)-1)) & ~((align)-1))
+
+/* free list node*/
+typedef struct alloc_node
+{
+	struct list_head node;
+	size_t size;
+	char* block;
+} alloc_node_t;
+
+/* allocation metadata size */
+#define ALLOC_HEADER_SZ __builtin_offsetof(alloc_node_t, block)
+
+/* minimum allocation size of 32 bytes */
+#define MIN_ALLOC_SZ ALLOC_HEADER_SZ + 32
+
+/* free list */
+static LIST_HEAD(free_list);
+
+static void coalesce_free_list(void)
+{
+	alloc_node_t *b, *lb = NULL, *t;
+
+	list_for_each_entry_safe(b, t, &free_list, node)
+	{
+		if (lb)
+		{
+			/* coalesce adjacent blocks */
+			if ((((uintptr_t)&lb->block) + lb->size) == (uintptr_t)b)
+			{
+				lb->size += sizeof(*b) + b->size;
+				list_del(&b->node);
+				continue;
+			}
+		}
+		lb = b;
+	}
+}
+
+void* malloc(size_t size)
+{
+	void* ptr = NULL;
+	alloc_node_t* blk = NULL;
+
+	if (size > 0)
+	{
+		/* Align the pointer */
+		size = ALIGN_SIZE(size, sizeof(void*));
+
+		/* try to find a big enough block */
+		list_for_each_entry(blk, &free_list, node)
+		{
+			if (blk->size >= size)
+			{
+				ptr = &blk->block;
+				break;
+			}
+		}
+
+		if (ptr)
+		{
+			/* split block if possible */
+			if ((blk->size - size) >= MIN_ALLOC_SZ)
+			{
+				alloc_node_t* new_blk;
+				new_blk = (alloc_node_t*)((uintptr_t)(&blk->block) + size);
+				new_blk->size = blk->size - size - ALLOC_HEADER_SZ;
+				blk->size = size;
+				list_add(&new_blk->node, &blk->node);
+			}
+
+			list_del(&blk->node);
+		}
+
+	}
+
+	return ptr;
+}
+
+void free(void* ptr)
+{
+	alloc_node_t *blk, *free_blk;
+
+	if (ptr)
+	{
+		blk = container_of(ptr, alloc_node_t, block);
+
+		/* add block to free list in ascending order by pointer */
+		list_for_each_entry(free_blk, &free_list, node)
+		{
+			if (free_blk > blk)
+			{
+				list_add_tail(&blk->node, &free_blk->node);
+				goto blockadded;
+			}
+		}
+		list_add_tail(&blk->node, &free_list);
+
+	blockadded:
+		coalesce_free_list();
+	}
+}
+
+void _malloc_addblock(void* addr, size_t size)
+{
+	alloc_node_t* blk;
+
+	/* pointer align the block */
+	blk = (alloc_node_t*)ALIGN_SIZE((uintptr_t)addr, sizeof(void*));
+
+	/* calculate usable size */
+	blk->size = (uintptr_t)addr + size - (uintptr_t)blk - ALLOC_HEADER_SZ;
+
+	/* add the block to the free list */
+	list_add(&blk->node, &free_list);
+}