发信人: snows (花自飘零水自流), 信区: Embedded
标 题: The init() Function
发信站: 哈工大紫丁香 (2004年03月16日13:29:39 星期二), 站内信件
The init() Function
Init() is located in init/main.c.
Init() completes the kernel's boot process by calling do_basic_setup() to
initialize the kernel's PCI and network features. The remaining memory
allocated for initialization is discarded, scheduling is enabled, the
standard input, output and error streams are created, and prepare_namespace()
is called to mount the root filesystem.
With the root filesystem in place, init() runs execve() to launch the program
/sbin/init, if it exists. If a valid program name is provided with the
init=<programname> command line option, init() will execve() that program
instead. If a suitable startup program cannot be found (the kernel also tries
"/bin/init" and "/bin/sh"), the kernel panics and halts.
The code for init() is shown in Figure 8.
static int init(void * unused)
{
lock_kernel();
do_basic_setup();
prepare_namespace();
free_initmem();
unlock_kernel();
if (open("/dev/console", O_RDWR, 0) < 0)
printk("Warning: unable to open an initial console.\n");
(void) dup(0);
(void) dup(0);
if (execute_command) execve(execute_command,argv_init,envp_init);
execve("/sbin/init", argv_init, envp_init);
execve("/bin/init",argv_init,envp_init);
execve("/bin/sh",argv_init,envp_init);
panic("No init found. Try passing init= option to kernel.");
}
Figure 8. The init() function.
--
-
╭────────────────────────────╮
│ 风萧传瑟声，叶落根深处，青阶入野无归途，他乡不知顾 │
│ 泣下问和谁，叹者行已暮，寒眉傲骨今尚在，奈何入凡土 │
╰────────────────────────────╯
※ 来源:·哈工大紫丁香 bbs.hit.edu.cn·[FROM: 202.118.229.154]