1 files changed, 52 insertions, 0 deletions
diff --git a/libgloss/or1k/sbrk.c b/libgloss/or1k/sbrk.c
new file mode 100644
index 000000000..de80663ee
--- /dev/null
+++ b/libgloss/or1k/sbrk.c
@@ -0,0 +1,52 @@
+/* sbrk.c -- allocate space on heap on OpenRISC 1000.
+ *
+ * Copyright (c) 2014 Authors
+ *
+ * Contributor Stefan Wallentowitz <stefan.wallentowitz@tum.de>
+ *
+ * The authors hereby grant permission to use, copy, modify, distribute,
+ * and license this software and its documentation for any purpose, provided
+ * that existing copyright notices are retained in all copies and that this
+ * notice is included verbatim in any distributions. No written agreement,
+ * license, or royalty fee is required for any of the authorized uses.
+ * Modifications to this software may be copyrighted by their authors
+ * and need not follow the licensing terms described here, provided that
+ * the new terms are clearly indicated on the first page of each file where
+ * they apply.
+ */
+
+#include <reent.h>
+
+#include "include/or1k-support.h"
+
+static uint32_t _or1k_heap_end;
+
+void *
+_sbrk_r (struct _reent * reent, ptrdiff_t incr)
+{
+	extern uint32_t	end; /* Set by linker.  */
+	uint32_t	prev_heap_end;
+
+	// This needs to be atomic
+
+	// Disable interrupts on this core
+	uint32_t sr_iee = or1k_interrupts_disable();
+	uint32_t sr_tee = or1k_timer_disable();
+
+	// Initialize heap end to end if not initialized before
+	or1k_sync_cas((void*) &_or1k_heap_end, 0, (uint32_t) &end);
+
+	do {
+		// Read previous heap end
+		prev_heap_end = _or1k_heap_end;
+		// and try to set it to the new value as long as it has changed
+	} while (or1k_sync_cas((void*) &_or1k_heap_end,
+			(uint32_t) prev_heap_end,
+			(uint32_t) (prev_heap_end + incr)) != (uint32_t) prev_heap_end);
+
+	// Restore interrupts on this core
+	or1k_timer_restore(sr_tee);
+	or1k_interrupts_restore(sr_iee);
+
+	return (void*) prev_heap_end;
+}