1 files changed, 118 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/lm3s/lm3s_pendsv.c b/nuttx/arch/arm/src/lm3s/lm3s_pendsv.c
new file mode 100644
index 000000000..1db255fef
--- /dev/null
+++ b/nuttx/arch/arm/src/lm3s/lm3s_pendsv.c
@@ -0,0 +1,118 @@
+/****************************************************************************
+ * arch/arm/src/lm3s/lm3s_pendsv.c
+ * arch/arm/src/chip/lm3s_pendsv.c
+ *
+ *   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+#include <sys/types.h>
+
+#include <string.h>
+#include <assert.h>
+#include <debug.h>
+
+#include <arch/irq.h>
+
+#include "os_internal.h"
+#include "lm3s_internal.h"
+
+/****************************************************************************
+ * Private Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: lm3xs_pendxv
+ *
+ * Description:
+ *   This is PendSV exception handler that performs context switching
+ *
+ ****************************************************************************/
+
+int lm3s_pendsv(int irq, FAR void *context)
+{
+  uint32 *svregs  = (uint32*)context;
+  uint32 *tcbregs = (uint32*)svregs[REG_R1];
+
+  DEBUGASSERT(svregs && svregs == current_regs && tcbregs);
+
+  /* The PendSV software interrupt is called with R0 = PendSV command and R1 = 
+   * the TCB register save area.
+   */
+
+  switch (svregs[REG_R0])
+    {
+      /* R0=0:  This is a save context command.  In this case, we simply need
+       * to copy the svregs to the tdbregs and return.
+       */
+
+      case 0:
+        memcpy(tcbregs, svregs, XCPTCONTEXT_SIZE);
+        break;
+
+      /* R1=1: This a restore context command.  In this case, we simply need to
+       * set current_regs to tcbrgs.  svregs == current_regs is the normal exception
+       * turn.  By setting current_regs = tcbregs, we force the return through
+       * the saved context.
+       */
+
+      case 1:
+        current_regs = tcbregs;
+        break;
+
+      default:
+        PANIC(OSERR_INTERNAL);
+        break;
+    }
+
+  return OK;
+}