diff options
Diffstat (limited to 'nuttx/arch/arm/src/arm/up_fullcontextrestore.S')
| -rw-r--r-- | nuttx/arch/arm/src/arm/up_fullcontextrestore.S | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/arm/up_fullcontextrestore.S b/nuttx/arch/arm/src/arm/up_fullcontextrestore.S new file mode 100644 index 000000000..c99337636 --- /dev/null +++ b/nuttx/arch/arm/src/arm/up_fullcontextrestore.S @@ -0,0 +1,117 @@ +/************************************************************************** + * arch/arm/src/arm/up_fullcontextrestore.S + * + * Copyright (C) 2007, 2009 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 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" + +/************************************************************************** + * 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 */ + + /* Recover all registers except for r0, r1, R15, and CPSR */ + + add r1, r0, #(4*REG_R2) /* Offset to REG_R2 storage */ + ldmia r1, {r2-r14} /* Recover registers */ + + /* Create a stack frame to hold the PC */ + + sub sp, sp, #(3*4) /* Frame for three registers */ + ldr r1, [r0, #(4*REG_R0)] /* Fetch the stored r0 value */ + str r1, [sp] /* Save it at the top of the stack */ + ldr r1, [r0, #(4*REG_R1)] /* Fetch the stored r1 value */ + str r1, [sp, #4] /* Save it in the stack */ + ldr r1, [r0, #(4*REG_PC)] /* Fetch the stored pc value */ + str r1, [sp, #8] /* Save it at the bottom of the frame */ + + /* Now we can restore the CPSR. We wait until we are completely + * finished with the context save data to do this. Restore the CPSR + * may re-enable and interrupts and we couldt be in a context + * where save structure is only protected by interrupts being disabled. + */ + + ldr r1, [r0, #(4*REG_CPSR)] /* Fetch the stored CPSR value */ + msr cpsr, r1 /* Set the CPSR */ + + /* Now recover r0 and r1 */ + + ldr r0, [sp] + ldr r1, [sp, #4] + add sp, sp, #(2*4) + + /* Then return to the address at the stop of the stack, + * destroying the stack frame + */ + + ldr pc, [sp], #4 + .size up_fullcontextrestore, . - up_fullcontextrestore + |