| /************************************************************************** |
| * common/up_saveusercontext.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_saveusercontext |
| **************************************************************************/ |
| |
| .text |
| .globl up_saveusercontext |
| .type up_saveusercontext, function |
| up_saveusercontext: |
| /* On entry, a1 (r0) holds address of struct xcptcontext. |
| * Offset to the user region. |
| */ |
| |
| /* 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 throught the |
| * noraml 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] |
| |
| /* Finally 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] |
| |
| /* Return 0 */ |
| |
| mov r0, #0 /* Return value == 0 */ |
| mov pc, lr /* Return */ |
| .size up_saveusercontext, . - up_saveusercontext |
| |
