cttyhack: serial console detection is Linux-specific

Signed-off-by: Jeremie Koenig <jk@jk.fr.eu.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 12 insertions, 3 deletions

diff --git a/shell/cttyhack.c b/shell/cttyhack.c
index a80d49dc3..3a78bae29 100644
--- a/shell/cttyhack.c
+++ b/shell/cttyhack.c
@@ -13,7 +13,6 @@
 //config:config CTTYHACK
 //config:       bool "cttyhack"
 //config:       default y
-//config:       depends on PLATFORM_LINUX
 //config:       help
 //config:         One common problem reported on the mailing list is "can't access tty;
 //config:         job control turned off" error message which typically appears when
@@ -59,6 +58,10 @@
 //usage:     "\nStarting interactive shell from boot shell script:"
 //usage:     "\n        setsid cttyhack sh"
 
+#if !defined(__linux__) && !defined(TIOCGSERIAL)
+# warning cttyhack will not be able to detect a controlling tty on this system
+#endif
+
 /* From <linux/vt.h> */
 struct vt_stat {
         unsigned short v_active;        /* active vt */
@@ -112,13 +115,19 @@ int cttyhack_main(int argc UNUSED_PARAM, char **argv)
                 close(fd);
         } else {
                 /* We don't have ctty (or don't have "/dev/tty" node...) */
-                if (ioctl(0, TIOCGSERIAL, &u.sr) == 0) {
+                if (0) {}
+#ifdef TIOCGSERIAL
+                else if (ioctl(0, TIOCGSERIAL, &u.sr) == 0) {
                         /* this is a serial console */
                         sprintf(console + 8, "S%d", u.sr.line);
-                } else if (ioctl(0, VT_GETSTATE, &u.vt) == 0) {
+                }
+#endif
+#ifdef __linux__
+                else if (ioctl(0, VT_GETSTATE, &u.vt) == 0) {
                         /* this is linux virtual tty */
                         sprintf(console + 8, "S%d" + 1, u.vt.v_active);
                 }
+#endif
                 if (console[8]) {
                         fd = xopen(console, O_RDWR);
                         //bb_error_msg("switching to '%s'", console);