From f1c86531af75a9f6ad02ed2de96decf0d0382358 Mon Sep 17 00:00:00 2001 From: pm2qzlfkv <3316749729@qq.com> Date: Mon, 4 Dec 2023 19:21:39 +0800 Subject: [PATCH] ADD file via upload --- init.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 init.c diff --git a/init.c b/init.c new file mode 100644 index 00000000..d300e499 --- /dev/null +++ b/init.c @@ -0,0 +1,101 @@ +/* + * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved. + * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved. + * + * 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 of the copyright holder 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 HOLDER 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. + */ + +#include +#include +#include +#include +#include + +#ifdef LOSCFG_QUICK_START +#include +#include +#include +#include +#include + +#define QUICKSTART_IOC_MAGIC 'T' +#define QUICKSTART_INITSTEP2 _IO(QUICKSTART_IOC_MAGIC, 0) +#define WAIT_FOR_SAMPLE 300000 // wait 300ms for sample +#endif +int main(int argc, char * const *argv) +{ + (void)argv; + int ret; // 声明一个整数变量ret，用于存储函数的返回值 + pid_t gid; // 声明一个pid_t类型的变量gid，用于存储进程组ID + const char *shellPath = "/bin/mksh";// 定义一个字符串常量shellPath，存储shell的路径，这里使用的是mksh shell + // 以下部分是一个条件编译块，如果定义了LOSCFG_QUICK_START宏，这段代码会被编译进程序 +#ifdef LOSCFG_QUICK_START + const char *samplePath = "/dev/shm/sample_quickstart";// 定义一个字符串常量samplePath，存储sample_quickstart的路径 + // 使用fork函数创建子进程，返回值存储在ret变量中 + // 如果ret小于0，说明创建子进程失败；如果ret等于0，说明这是子进程；如果ret大于0，说明这是父进程，ret是子进程的ID + ret = fork(); + if (ret < 0) { // 如果创建子进程失败，输出错误消息 + printf("Failed to fork for sample_quickstart\n"); + } else if (ret == 0) {// 如果是子进程，获取进程组ID并存储在gid变量中，如果获取失败，输出错误消息并退出 + (void)execve(samplePath, NULL, NULL); + exit(0); + } + + usleep(WAIT_FOR_SAMPLE); + + int fd = open("/dev/quickstart", O_RDONLY); + if (fd != -1) { + ioctl(fd, QUICKSTART_INITSTEP2); + close(fd); + } +#endif + ret = fork(); + if (ret < 0) { + printf("Failed to fork for shell\n"); + } else if (ret == 0) { + gid = getpgrp(); + if (gid < 0) { + printf("get group id failed, pgrpid %d, errno %d\n", gid, errno); + exit(0); + } + ret = tcsetpgrp(STDIN_FILENO, gid); + if (ret != 0) {// 如果是子进程，尝试将STDIN（标准输入）重定向到指定的进程组（通过tcsetpgrp函数实现），如果重定向失败，输出错误消息并退出 + printf("tcsetpgrp failed, errno %d\n", errno); + exit(0); + } + // 如果是子进程，使用execve函数执行shellPath指定的shell程序，参数为NULL，环境变量为NULL + (void)execve(shellPath, NULL, NULL); + exit(0); + } + + while (1) { // 如果是父进程，进入一个无限循环，不断地调用waitpid函数等待子进程的状态变化（通过WNOHANG标志实现） + ret = waitpid(-1, 0, WNOHANG); // 如果子进程还在运行，等待1秒后再次检查；如果子进程已经停止运行，继续等待下一次检查（通过waitpid函数实现） + if (ret == 0) { + sleep(1); + } + }; +}