lunaix-os/usr/init/init.c

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