lunaix-os/usr/init/init.c

   1 #include <errno.h>
   2 #include <fcntl.h>
   3 #include <sys/wait.h>
   4 #include <sys/mount.h>
   5 #include <termios.h>
   6 #include <stdio.h>
   7 #include <unistd.h>
   8
   9 #include <sys/lunaix.h>
  10
  11 #define must_mount(src, target, fs, opts)                                      \
  12     do {                                                                       \
  13         int err = 0;                                                           \
  14         if ((err = mount(src, target, fs, opts))) {                            \
  15             syslog(2, "mount fs %s to %s failed (%d)\n", fs, target, errno);   \
  16             return err;                                                        \
  17         }                                                                      \
  18     } while (0)
  19
  20 #define maybe_mount(src, target, fs, opts)                                      \
  21     do {                                                                       \
  22         int err = 0;                                                           \
  23         if ((err = mount(src, target, fs, opts))) {                            \
  24             syslog(2, "mount fs %s to %s failed (%d)\n", fs, target, errno);   \
  25         }                                                                      \
  26     } while (0)
  27
  28 #define check(statement)                                                       \
  29     ({                                                                         \
  30         int err = 0;                                                           \
  31         if ((err = (statement)) < 0) {                                         \
  32             syslog(2, #statement " failed: %d", err);                          \
  33             _exit(1);                                                          \
  34         }                                                                      \
  35         err;                                                                   \
  36     })
  37
  38 int
  39 init_termios(int fd) {
  40     struct termios term;
  41
  42     check(tcgetattr(fd, &term));
  43
  44     term.c_lflag = ICANON | IEXTEN | ISIG | ECHO | ECHOE;
  45     term.c_iflag = ICRNL | IGNBRK;
  46     term.c_oflag = ONLCR | OPOST;
  47     term.c_cflag = CREAD | CLOCAL | CS8 | CPARENB;
  48     term.c_cc[VERASE] = 0x7f;
  49
  50     cfsetispeed(&term, B9600);
  51     cfsetospeed(&term, B9600);
  52
  53     check(tcsetattr(fd, 0, &term));
  54
  55     return 0;
  56 }
  57
  58 const char* sh_argv[] = { "/bin/sh", 0  };
  59 const char* sh_envp[] = {  0  };
  60
  61 int
  62 main(int argc, const char** argv)
  63 {
  64     must_mount(NULL, "/dev", "devfs", 0);
  65     must_mount(NULL, "/sys", "twifs", MNT_RO);
  66     must_mount(NULL, "/task", "taskfs", MNT_RO);
  67
  68     int fd = check(open("/dev/tty", 0));
  69
  70     check(init_termios(fd));
  71
  72     check(dup(fd));
  73
  74     pid_t pid;
  75     int err = 0;
  76     if (!(pid = fork())) {
  77         err = execve(sh_argv[0], sh_argv, sh_envp);
  78         printf("fail to execute (%d)\n", errno);
  79         _exit(err);
  80     }
  81
  82     waitpid(pid, &err, 0);
  83
  84     if (WEXITSTATUS(err)) {
  85         printf("shell exit abnormally (%d)\n", err);
  86     }
  87
  88     printf("init exiting\n");
  89
  90     return err;
  91 }