2335b69120
arch: Allocate the space from the beginning in up_stack_frame and modify the affected portion: 1.Correct the stack dump and check 2.Allocate tls_info_s by up_stack_frame too 3.Move the stack fork allocation from arch to sched Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
128 lines
4.7 KiB
ArmAsm
128 lines
4.7 KiB
ArmAsm
/****************************************************************************
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* arch/arm/src/armv6-m/vfork.S
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include "arm_vfork.h"
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/****************************************************************************
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* Pre-processor Definitions
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****************************************************************************/
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/****************************************************************************
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* Public Symbols
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****************************************************************************/
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.file "vfork.S"
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.globl up_vfork
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: vfork
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*
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* Description:
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* The vfork() function has the same effect as fork(), except that the
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* behavior is undefined if the process created by vfork() either modifies
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* any data other than a variable of type pid_t used to store the return
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* value from vfork(), or returns from the function in which vfork() was
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* called, or calls any other function before successfully calling _exit()
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* or one of the exec family of functions.
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*
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* This thin layer implements vfork by simply calling up_vfork() with the
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* vfork() context as an argument. The overall sequence is:
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*
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* 1) User code calls vfork(). vfork() collects context information and
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* transfers control up up_vfork().
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* 2) up_vfork() and calls nxtask_setup_vfork().
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* 3) nxtask_setup_vfork() allocates and configures the child task's TCB.
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* This consists of:
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* - Allocation of the child task's TCB.
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* - Initialization of file descriptors and streams
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* - Configuration of environment variables
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* - Allocate and initialize the stack
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* - Setup the input parameters for the task.
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* - Initialization of the TCB (including call to up_initial_state())
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* 4) up_vfork() provides any additional operating context. up_vfork must:
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* - Initialize special values in any CPU registers that were not
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* already configured by up_initial_state()
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* 5) up_vfork() then calls nxtask_start_vfork()
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* 6) nxtask_start_vfork() then executes the child thread.
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*
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* Input Parameters:
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* None
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*
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* Returned Value:
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* Upon successful completion, vfork() returns 0 to the child process and
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* returns the process ID of the child process to the parent process.
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* Otherwise, -1 is returned to the parent, no child process is created,
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* and errno is set to indicate the error.
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*
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****************************************************************************/
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.align 2
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.code 16
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.thumb_func
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.globl vfork
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.type vfork, function
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vfork:
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/* Create a stack frame */
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mov r0, sp /* Save the value of the stack on entry */
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sub sp, sp, #VFORK_SIZEOF /* Allocate the structure on the stack */
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/* CPU registers */
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/* Save the volatile registers */
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mov r1, sp
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stmia r1!, {r4-r7} /* Save r4-r7 in the structure */
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mov r4, r8 /* Copy high registers to low registers */
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mov r5, r9
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mov r6, r10
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mov r7, fp
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stmia r1!, {r4-r7} /* Save r8-r10 and fp in the structure */
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mov r5, lr /* Copy lr to a low register */
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stmia r1!, {r0,r5} /* Save sp and lr in the structure */
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/* Then, call up_vfork(), passing it a pointer to the stack structure */
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mov r0, sp
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bl up_vfork
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/* Recover r4-r7 that were destroyed before up_vfork was called */
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mov r1, sp
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ldmia r1!, {r4-r7}
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/* Release the stack data and return the value returned by up_vfork */
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ldr r1, [sp, #VFORK_LR_OFFSET]
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mov r14, r1
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add sp, sp, #VFORK_SIZEOF
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bx lr
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.size vfork, .-vfork
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.end
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