143 lines
5.1 KiB
ArmAsm
143 lines
5.1 KiB
ArmAsm
/****************************************************************************
|
|
* arch/arm/src/armv7-a/arm_saveusercontext.S
|
|
*
|
|
* Copyright (C) 2013 Gregory Nutt. All rights reserved.
|
|
* Author: Gregory Nutt <gnutt@nuttx.org>
|
|
*
|
|
* 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/irq.h>
|
|
#include "up_internal.h"
|
|
|
|
.file "arm_saveusercontext.S"
|
|
|
|
/****************************************************************************
|
|
* Preprocessor Definitions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Symbols
|
|
****************************************************************************/
|
|
|
|
.globl up_saveusercontext
|
|
|
|
/****************************************************************************
|
|
* Private Data
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Data
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
.text
|
|
|
|
/****************************************************************************
|
|
* Name: up_saveusercontext
|
|
****************************************************************************/
|
|
|
|
.globl up_saveusercontext
|
|
.type up_saveusercontext, function
|
|
|
|
up_saveusercontext:
|
|
|
|
/* On entry, a1 (r0) holds address of struct xcptcontext */
|
|
|
|
/* Make sure that the return value will be non-zero (the value of the
|
|
* other volatile registers don't matter -- r1-r3, ip). This function
|
|
* is called through the normal C calling conventions and the values of
|
|
* these registers cannot be assumed at the point of setjmp return.
|
|
*/
|
|
|
|
mov ip, #1
|
|
str ip, [r0, #(4*REG_R0)]
|
|
|
|
/* Save the volatile registers (plus r12 which really
|
|
* doesn't need to be saved)
|
|
*/
|
|
|
|
add r1, r0, #(4*REG_R4)
|
|
stmia r1, {r4-r14}
|
|
|
|
/* Save the current cpsr */
|
|
|
|
mrs r2, cpsr /* R3 = CPSR value */
|
|
add r1, r0, #(4*REG_CPSR)
|
|
str r2, [r1]
|
|
|
|
/* Save the return address as the PC so that we return to the exit from
|
|
* this function.
|
|
*/
|
|
|
|
add r1, r0, #(4*REG_PC)
|
|
str lr, [r1]
|
|
|
|
/* Save the floating point registers.
|
|
* REVISIT: Not all of the floating point registers need to be saved.
|
|
* Some are volatile and need not be preserved across functions calls.
|
|
* But right now, I can't find the definitive list of the volatile
|
|
* floating point registers.
|
|
*/
|
|
|
|
#ifdef CONFIG_ARCH_FPU
|
|
add r1, r0, #(4*REG_S0) /* R1=Address of FP register storage */
|
|
|
|
/* Store all floating point registers. Registers are stored in numeric order,
|
|
* s0, s1, ... in increasing address order.
|
|
*/
|
|
|
|
vstmia r1!, {s0-s31} /* Save the full FP context */
|
|
|
|
/* Store the floating point control and status register. At the end of the
|
|
* vstmia, r1 will point to the FPCSR storage location.
|
|
*/
|
|
|
|
vmrs r2, fpscr /* Fetch the FPCSR */
|
|
str r2, [r1], #4 /* Save the floating point control and status register */
|
|
#endif
|
|
|
|
/* Return 0 now indicating that this return is not a context switch */
|
|
|
|
mov r0, #0 /* Return value == 0 */
|
|
mov pc, lr /* Return */
|
|
.size up_saveusercontext, . - up_saveusercontext
|
|
.end
|