SPARC: bsp_early_malloc() routine for startup memory allocation

If bsp_early_malloc() is called early during boot room will be
allocated after BSS END. If the function is called after boot
is will call malloc() instead. The returned memory is not freeable
and always 8-byte aligned.

If the bsp_early_malloc() isn't called the function is not
dragged in and the workspace will be unmodified in size.

Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/c/src/lib/libbsp/sparc/shared/startup/early_malloc.c b/c/src/lib/libbsp/sparc/shared/startup/early_malloc.c
new file mode 100644
index 0000000000..1f968da206
--- /dev/null
+++ b/c/src/lib/libbsp/sparc/shared/startup/early_malloc.c
@@ -0,0 +1,47 @@
+/*
+ *  Early dynamic memory allocation (not freeable) for BSP
+ *  boot routines. Minimum alignment 8 bytes. Memory is
+ *  allocated after _end, it will shrink the workspace.
+ *
+ *  COPYRIGHT (c) 2011.
+ *  Aeroflex Gaisler AB
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ */
+
+#include <bsp.h>
+#include <stdlib.h>
+
+/* Tells us where to put the workspace in case remote debugger is present. */
+extern uint32_t rdb_start;
+
+/* Must be aligned to 8 */
+extern unsigned int early_mem;
+
+/* must be identical to STACK_SIZE in start.S */
+#define STACK_SIZE (16 * 1024)
+
+/* Allocate 8-byte aligned non-freeable pre-malloc() memory. The function
+ * can be called at any time. The work-area will shrink when called before
+ * bsp_get_work_area(). malloc() is called to get memory when this function
+ * is called after bsp_get_work_area().
+ */
+void *bsp_early_malloc(int size)
+{
+	void *start;
+
+	/* Not early anymore? */
+	if (early_mem == ~0)
+		return malloc(size);
+
+	size = (size + 7) & ~0x7;
+	if (rdb_start - STACK_SIZE - early_mem < size)
+		return NULL;
+
+	start = (void *)early_mem;
+	early_mem += size;
+
+	return start;
+}