/**************************************************************************
* up_savecontext.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 <sys/types.h>
#include <nuttx/irq.h>
#include "up_internal.h"
/**************************************************************************
* Private Definitions
**************************************************************************/
/**************************************************************************
* Private Types
**************************************************************************/
/**************************************************************************
* Private Function Prototypes
**************************************************************************/
/**************************************************************************
* Global Variables
**************************************************************************/
/**************************************************************************
* Private Variables
**************************************************************************/
/**************************************************************************
* Private Functions
**************************************************************************/
/**************************************************************************
* Public Functions
**************************************************************************/
/**************************************************************************
* Name: up_savecontext
*
* Description:
* Push the current execution context onto the stack, then save the
* entire stack contents in the provided context structure.
*
* Inputs:
* context - the context structure in which to save the stack info
*
* Return:
* 0 = Normal state save return
* 1 = This is the matching return from up_restorecontext()
*
**************************************************************************/
ubyte up_savecontext(FAR struct xcptcontext *context) _naked
{
_asm
/* Create the stack frame that we want when it is time to restore
* this* context. The return address will be the return address
* of this function, the return value will be zero.
*/
clr a
push acc /* ACC = 0 */
push ie
mov a, #1
push acc /* DPL = 1 */
clr a
push acc /* DPH = 0 */
push b
push ar2
push ar3
push ar4
push ar5
push ar6
push ar7
push ar0
push ar1
push psw
clr psw
push _bp
/* Disable interrupts while we create a snapshot of the stack */
push ie
mov ea, 0
/* Now copy the current stack frame (including the saved execution
* context) from internal RAM to XRAM.
*/
push sp
lcall _up_savestack
pop acc
/* Restore the interrupt state */
pop ie
/* Now that we have a snapshot of the desired stack frame saved,
* restore the correct stackpointer.
*/
mov a, sp
subb a, #15
mov sp, a
mov dpl,#0
ret
_endasm;
}
/**************************************************************************
* Name: up_savestack
*
* Description:
* Save the entire interrupt stack contents in the provided context
* structure.
*
* Inputs:
* context - the context structure in which to save the stack info
*
* Return:
* None
*
* Assumptions:
* - Interrupts are disabled
*
**************************************************************************/
void up_savestack(FAR struct xcptcontext *context, ubyte tos)
{
/* Now copy the current stack frame (including the saved execution
* context) from internal RAM to XRAM.
*/
ubyte nbytes = tos - (STACK_BASE-1);
NEAR ubyte *src = (NEAR ubyte*)STACK_BASE;
FAR ubyte *dest = context->stack;
context->nbytes = nbytes;
while (nbytes--)
{
*dest++ = *src++;
}
}
