Initial sources import 1/3

source files mainly done by Randall.

Signed-off-by: Randall Spangler <rspangler@chromium.org>

Change-Id: Iaff83a842b17f3350fb6f2a3f1597ad4c29bd12a

1 files changed, 54 insertions, 0 deletions

diff --git a/common/shared_mem.c b/common/shared_mem.c
new file mode 100644
index 0000000000..bff3ec6da3
--- /dev/null
+++ b/common/shared_mem.c
@@ -0,0 +1,54 @@
+/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* Shared memory module for Chrome EC */
+
+#include "shared_mem.h"
+#include "uart.h"
+
+/* Size of shared memory buffer */
+#define SHARED_MEM_SIZE 4096
+
+static char shared_buf[SHARED_MEM_SIZE];
+static int buf_in_use = 0;
+
+
+int shared_mem_init(void)
+{
+	return EC_SUCCESS;
+}
+
+
+int shared_mem_size(void)
+{
+	return SHARED_MEM_SIZE;
+}
+
+
+int shared_mem_acquire(int size, int wait, char **dest_ptr)
+{
+	if (size > SHARED_MEM_SIZE || size <= 0)
+		return EC_ERROR_INVAL;
+
+	/* TODO: if task_start() hasn't been called, fail immediately
+	 * if not available. */
+
+	/* TODO: wait if requested; for now, we fail immediately if
+	 * not available. */
+	if (buf_in_use)
+		return EC_ERROR_BUSY;
+
+	/* TODO: atomically acquire buf_in_use. */
+	buf_in_use = 1;
+	*dest_ptr = shared_buf;
+	return EC_SUCCESS;
+}
+
+
+void shared_mem_release(void *ptr)
+{
+	/* TODO: use event to wake up a previously-blocking acquire */
+	buf_in_use = 0;
+}