From 965df7faefabdd5f571b5eb46d45470223c91e12 Mon Sep 17 00:00:00 2001
From: "Nicolas \"Pixel\" Noble" <pixel@nobis-crew.org>
Date: Mon, 24 Jan 2011 10:35:19 +0100
Subject: Adding sbrk, and fixing a couple of other makefile problems.
---
os/src/sbrk.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
create mode 100644 os/src/sbrk.c
(limited to 'os/src')
diff --git a/os/src/sbrk.c b/os/src/sbrk.c
new file mode 100644
index 0000000..3c674ba
--- /dev/null
+++ b/os/src/sbrk.c
@@ -0,0 +1,47 @@
+#include <reent.h>
+#include <errno.h>
+#include <stdlib.h>
+
+#include "FreeRTOS.h"
+#include "task.h"
+#include "mpu_wrappers.h"
+
+// Mostly stolen from mbed-freertos
+
+extern unsigned int __cs3_heap_start, __cs3_heap_end;
+
+/* Low-level bulk RAM allocator -- used by Newlib's Malloc */
+void *heap_end = NULL;
+PRIVILEGED_FUNCTION void *_sbrk_r(struct _reent *ptr, ptrdiff_t incr)
+{
+ void *prev_heap_end, *next_heap_end, *ret;
+
+ taskENTER_CRITICAL();
+ {
+ /* Initialize on first call */
+ if (heap_end == NULL)
+ {
+ heap_end = (void *)&__cs3_heap_start;
+ }
+
+ prev_heap_end = heap_end;
+
+ /* Align to always be on 8-byte boundaries */
+ next_heap_end = (void *)((((unsigned int)heap_end + incr) + 7) & ~7);
+
+ /* Check if this allocation would exceed the end of the ram - would probably get into the stack first however */
+ if (next_heap_end > (void *)&__cs3_heap_end)
+ {
+ ptr->_errno = ENOMEM;
+ ret = NULL;
+ }
+ else
+ {
+ heap_end = next_heap_end;
+ ret = (void *)prev_heap_end;
+ }
+ }
+ taskEXIT_CRITICAL();
+ return ret;
+}
+
--
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