116 lines
4.5 KiB
ArmAsm
116 lines
4.5 KiB
ArmAsm
|
/**************************************************************************
|
||
|
|
* up_fullcontextrestore.S
|
||
|
|
*
|
||
|
|
* 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
|
||
|
|
**************************************************************************/
|
||
|
|
|
||
|
|
/**************************************************************************
|
||
|
|
* Public Functions
|
||
|
|
**************************************************************************/
|
||
|
|
|
||
|
|
/**************************************************************************
|
||
|
|
* Name: up_fullcontextrestore
|
||
|
|
**************************************************************************/
|
||
|
|
|
||
|
|
.globl up_fullcontextrestore
|
||
|
|
.type up_fullcontextrestore, function
|
||
|
|
up_fullcontextrestore:
|
||
|
|
|
||
|
|
/* On entry, a1 (r0) holds address of the register save area */
|
||
|
|
|
||
|
|
/* Restore the volatile registers. This is not necessary for
|
||
|
|
* normally task-to-task context switches (where the context
|
||
|
|
* was saved by up_saveusercontext()), but is necesary when
|
||
|
|
* the full context was saved through interrupt handling.
|
||
|
|
*/
|
||
|
|
|
||
|
|
/* Recover the user context (we will then have a new stack pointer) */
|
||
|
|
|
||
|
|
add r1, r0, #XCPTCONTEXT_UOFFSET
|
||
|
|
ldmia r1, {r3-r11, r13-r14}
|
||
|
|
|
||
|
|
/* Save the CSPR value and one scratch register on the stack */
|
||
|
|
|
||
|
|
sub sp, sp, #2*4 /* Create a frame to hold two regs */
|
||
|
|
stmia sp, {r3, r4} /* Save the CPSR (r3) and scratch (r4) */
|
||
|
|
|
||
|
|
/* Then recover the remaining registers */
|
||
|
|
|
||
|
|
ldmia r0, {r0-r3, r12} /* Recover volatile regs */
|
||
|
|
|
||
|
|
/* Now we can restore the CPSR (probably re-enabling interrupts) */
|
||
|
|
|
||
|
|
ldr r4, [sp]
|
||
|
|
msr cpsr, r4
|
||
|
|
|
||
|
|
/* Then recover the correct r4 value */
|
||
|
|
|
||
|
|
ldr r4, [sp, #4]
|
||
|
|
|
||
|
|
/* Destroy the temporary stack frame and return */
|
||
|
|
|
||
|
|
add sp, sp, #2*4
|
||
|
|
movs pc, lr
|
||
|
|
.size up_fullcontextrestore, . - up_fullcontextrestore
|
||
|
|
|