Import 8051 support

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@30 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 156 insertions, 0 deletions

diff --git a/nuttx/arch/pjrc-8051/src/up_restorecontext.c b/nuttx/arch/pjrc-8051/src/up_restorecontext.c
new file mode 100644
index 000000000..d1d095d91
--- /dev/null
+++ b/nuttx/arch/pjrc-8051/src/up_restorecontext.c
@@ -0,0 +1,156 @@
+/**************************************************************************
+ * up_restorecontext.c
+ *
+ *   Copyright (C) 2007 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 Gregory Nutt 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/irq.h>
+#include "up_internal.h"
+
+/**************************************************************************
+ * Private Definitions
+ **************************************************************************/
+
+/**************************************************************************
+ * Private Types
+ **************************************************************************/
+
+/**************************************************************************
+ * Private Function Prototypes
+ **************************************************************************/
+
+/**************************************************************************
+ * Global Variables
+ **************************************************************************/
+
+/**************************************************************************
+ * Private Variables
+ **************************************************************************/
+
+/**************************************************************************
+ * Private Functions
+ **************************************************************************/
+
+/**************************************************************************
+ * Name: up_popcontext
+ *
+ * Description:
+ *   Pop the current execution context from the stack and return to the
+ *   execution context.  Similar operations are executed from the interrupt
+ *   state restore
+ *
+ * Inputs:
+ *   None
+ *
+ * Return:
+ *   This function does not return
+ *
+ **************************************************************************/
+
+static void up_popcontext(ubyte newsp) __naked
+
+{
+  _asm 
+	pop	_bp 
+	pop	psw
+	pop	ar1 
+	pop	ar0 
+	pop	ar7 
+	pop	ar6 
+	pop	ar5 
+	pop	ar4 
+	pop	ar3 
+	pop	ar2 
+	pop	b 
+	pop	dph
+	pop	dpl 
+
+	/* Restore the interrupt state per the stored IE value */
+
+	pop	acc
+	jb	acc.7,00001$
+	clr	ie.7
+	sjmp	00002$
+  00001$:
+	setb	ie.7
+  00002$:
+
+	pop acc
+	ret
+  _endasm;
+}
+
+/**************************************************************************
+ * Public Functions
+ **************************************************************************/
+
+/**************************************************************************
+ * Name: up_restorecontext
+ *
+ * Description:
+ *   Restore the stack specified in the context structure and return to
+ *   that context
+ *
+ * Inputs:
+ *   context - Holds the stack content of the context to return to
+ *
+ * Return:
+ *   This function does not return.
+ *
+ **************************************************************************/
+
+void up_restorecontext(FAR struct xcptcontext *context)
+{
+  int nbytes = context->nbytes;
+  FAR ubyte *src = context->stack;
+  FAR ubyte *dest = (FAR ubyte*)STACK_BASE;
+
+  /* Interrupts should be disabled for the following.  up_popcontext() will
+   * set the new interrupt state correctly.
+   */
+
+  (void)irqsave();
+
+  while (nbytes--)
+    {
+      *src++ = *dest++;
+    }
+
+  /* Then return to the restored context */
+
+  up_popcontext(context->nbytes + (STACK_BASE-1));
+}
+