Linux启动顺序和修改启动后执行程序

vector_leizi

Linux kernel mounts the root filesystem.

The kernel starts the first user process /sbin/init provided by Busybox.

/sbin/init reads /etc/inittab (From the SDK: linux/embedded_rootfs/etc-files/inittab).

/etc/inittab starts the shell script /sbin/rc (From the SDK: linux/embedded_rootfs/etc-files/rc).

/sbin/rc mounts the kernel pseudo filesystems /proc, /dev/shm, and /dev/pts.

/sbin/rc brings up the loopback network device with the IP address 127.0.0.1.

/sbin/rc starts syslogd provided by Busybox.

/sbin/rc starts telnetd provided by Busybox.

/sbin/rc exits returning control in /sbin/init.

/etc/inittab tells /sbin/init to spawn an interactive shell.

The user interactive shell prompt appears.
修改rc文件即可设定linux自启动的程序，即启动linux后便会自己执行的程序或者shell脚步

static int noinline init_post(void)
{
free_initmem();
unlock_kernel();
mark_rodata_ro();
system_state = SYSTEM_RUNNING;
numa_default_policy();
if (sys_open((const char __user *) "/dev/console", O_RDWR, 0)
(void) sys_dup(0);
(void) sys_dup(0);
if (ramdisk_execute_command) {
  run_init_process(ramdisk_execute_command);
  printk(KERN_WARNING "Failed to execute %s\n",
    ramdisk_execute_command);
}
/*
  * We try each of these until one succeeds.
  *
  * The Bourne shell can be used instead of init if we are
  * trying to recover a really broken machine.
  */
if (execute_command) {
  run_init_process(execute_command);
  printk(KERN_WARNING "Failed to execute %s.  Attempting "
     "defaults...\n", execute_command);
}
run_init_process("/sbin/init");
run_init_process("/etc/init");
run_init_process("/bin/init");
run_init_process("/bin/sh");
panic("No init found.  Try passing init= option to kernel.");

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