nuttx/arch/arm/src/armv8-m/arm_saveusercontext.S
Gregory Nutt 010603329b More compliance to the naming standard.
1) Rename all up_*.S file to arm_*.S
2) Rename all functions used only by armv8_m logic from up_* to arm_*
2020-04-26 14:12:47 -03:00

89 lines
3.2 KiB
ArmAsm
Executable File

/************************************************************************************
* arch/arm/src/armv8-m/gnu/arm_saveusercontext.S
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
************************************************************************************/
/************************************************************************************
* Included Files
************************************************************************************/
#include <nuttx/config.h>
#include <arch/irq.h>
#include "nvic.h"
#include "svcall.h"
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
/************************************************************************************
* Public Symbols
************************************************************************************/
.syntax unified
.thumb
.file "arm_saveusercontext.S"
/************************************************************************************
* Macros
************************************************************************************/
/************************************************************************************
* Public Functions
************************************************************************************/
/************************************************************************************
* Name: arm_saveusercontext
*
* Description:
* Save the current thread context. Full prototype is:
*
* int arm_saveusercontext(uint32_t *saveregs);
*
* Returned Value:
* 0: Normal return
* 1: Context switch return
*
************************************************************************************/
.text
.thumb_func
.globl arm_saveusercontext
.type arm_saveusercontext, function
arm_saveusercontext:
/* Perform the System call with R0=0 and R1=regs */
mov r1, r0 /* R1: regs */
mov r0, #SYS_save_context /* R0: save context (also return value) */
svc 0 /* Force synchronous SVCall (or Hard Fault) */
/* There are two return conditions. On the first return, R0 (the
* return value will be zero. On the second return we need to
* force R0 to be 1.
*/
add r2, r1, #(4*REG_R0)
mov r3, #1
str r3, [r2, #0]
bx lr /* "normal" return with r0=0 or
* context switch with r0=1 */
.size arm_saveusercontext, .-arm_saveusercontext
.end