/* This file contains the terminal driver, both for the IBM console and regular * ASCII terminals. It handles only the device-independent part of a TTY, the * device dependent parts are in console.c, rs232.c, etc. This file contains * two main entry points, tty_task() and tty_wakeup(), and several minor entry * points for use by the device-dependent code. * * The device-independent part accepts "keyboard" input from the device- * dependent part, performs input processing (special key interpretation), * and sends the input to a process reading from the TTY. Output to a TTY * is sent to the device-dependent code for output processing and "screen" * display. Input processing is done by the device by calling 'in_process' * on the input characters, output processing may be done by the device itself * or by calling 'out_process'. The TTY takes care of input queuing, the * device does the output queuing. If a device receives an external signal, * like an interrupt, then it causes tty_wakeup() to be run by the CLOCK task * to, you guessed it, wake up the TTY to check if input or output can * continue. * * The valid messages and their parameters are: * * HARD_INT: output has been completed or input has arrived * SYS_SIG: e.g., MINIX wants to shutdown; run code to cleanly stop * DEV_READ: a process wants to read from a terminal * DEV_WRITE: a process wants to write on a terminal * DEV_IOCTL: a process wants to change a terminal's parameters * DEV_OPEN: a tty line has been opened * DEV_CLOSE: a tty line has been closed * DEV_SELECT: start select notification request * DEV_STATUS: FS wants to know status for SELECT or REVIVE * CANCEL: terminate a previous incomplete system call immediately * * m_type TTY_LINE PROC_NR COUNT TTY_SPEK TTY_FLAGS ADDRESS * --------------------------------------------------------------------------- * | HARD_INT | | | | | | | * |-------------+---------+---------+---------+---------+---------+---------| * | SYS_SIG | sig set | | | | | | * |-------------+---------+---------+---------+---------+---------+---------| * | DEV_READ |minor dev| proc nr | count | O_NONBLOCK| buf ptr | * |-------------+---------+---------+---------+---------+---------+---------| * | DEV_WRITE |minor dev| proc nr | count | | | buf ptr | * |-------------+---------+---------+---------+---------+---------+---------| * | DEV_IOCTL |minor dev| proc nr |func code|erase etc| flags | | * |-------------+---------+---------+---------+---------+---------+---------| * | DEV_OPEN |minor dev| proc nr | O_NOCTTY| | | | * |-------------+---------+---------+---------+---------+---------+---------| * | DEV_CLOSE |minor dev| proc nr | | | | | * |-------------+---------+---------+---------+---------+---------+---------| * | DEV_STATUS | | | | | | | * |-------------+---------+---------+---------+---------+---------+---------| * | CANCEL |minor dev| proc nr | | | | | * --------------------------------------------------------------------------- * * Changes: * Jan 20, 2004 moved TTY driver to user-space (Jorrit N. Herder) * Sep 20, 2004 local timer management/ sync alarms (Jorrit N. Herder) * Jul 13, 2004 support for function key observers (Jorrit N. Herder) */ #include "../drivers.h" #include "../drivers.h" #include #include #include #include #include #include "tty.h" #include #include extern int irq_hook_id; unsigned long kbd_irq_set = 0; unsigned long rs_irq_set = 0; /* Address of a tty structure. */ #define tty_addr(line) (&tty_table[line]) /* Macros for magic tty types. */ #define isconsole(tp) ((tp) < tty_addr(NR_CONS)) #define ispty(tp) ((tp) >= tty_addr(NR_CONS+NR_RS_LINES)) /* Macros for magic tty structure pointers. */ #define FIRST_TTY tty_addr(0) #define END_TTY tty_addr(sizeof(tty_table) / sizeof(tty_table[0])) /* A device exists if at least its 'devread' function is defined. */ #define tty_active(tp) ((tp)->tty_devread != NULL) /* RS232 lines or pseudo terminals can be completely configured out. */ #if NR_RS_LINES == 0 #define rs_init(tp) ((void) 0) #endif #if NR_PTYS == 0 #define pty_init(tp) ((void) 0) #define do_pty(tp, mp) ((void) 0) #endif FORWARD _PROTOTYPE( void tty_timed_out, (timer_t *tp) ); FORWARD _PROTOTYPE( void expire_timers, (void) ); FORWARD _PROTOTYPE( void settimer, (tty_t *tty_ptr, int enable) ); FORWARD _PROTOTYPE( void do_cancel, (tty_t *tp, message *m_ptr) ); FORWARD _PROTOTYPE( void do_ioctl, (tty_t *tp, message *m_ptr) ); FORWARD _PROTOTYPE( void do_open, (tty_t *tp, message *m_ptr) ); FORWARD _PROTOTYPE( void do_close, (tty_t *tp, message *m_ptr) ); FORWARD _PROTOTYPE( void do_read, (tty_t *tp, message *m_ptr) ); FORWARD _PROTOTYPE( void do_write, (tty_t *tp, message *m_ptr) ); FORWARD _PROTOTYPE( void do_select, (tty_t *tp, message *m_ptr) ); FORWARD _PROTOTYPE( void do_status, (message *m_ptr) ); FORWARD _PROTOTYPE( void in_transfer, (tty_t *tp) ); FORWARD _PROTOTYPE( int tty_echo, (tty_t *tp, int ch) ); FORWARD _PROTOTYPE( void rawecho, (tty_t *tp, int ch) ); FORWARD _PROTOTYPE( int back_over, (tty_t *tp) ); FORWARD _PROTOTYPE( void reprint, (tty_t *tp) ); FORWARD _PROTOTYPE( void dev_ioctl, (tty_t *tp) ); FORWARD _PROTOTYPE( void setattr, (tty_t *tp) ); FORWARD _PROTOTYPE( void tty_icancel, (tty_t *tp) ); FORWARD _PROTOTYPE( void tty_init, (void) ); /* Default attributes. */ PRIVATE struct termios termios_defaults = { TINPUT_DEF, TOUTPUT_DEF, TCTRL_DEF, TLOCAL_DEF, TSPEED_DEF, TSPEED_DEF, { TEOF_DEF, TEOL_DEF, TERASE_DEF, TINTR_DEF, TKILL_DEF, TMIN_DEF, TQUIT_DEF, TTIME_DEF, TSUSP_DEF, TSTART_DEF, TSTOP_DEF, TREPRINT_DEF, TLNEXT_DEF, TDISCARD_DEF, }, }; PRIVATE struct winsize winsize_defaults; /* = all zeroes */ /* Global variables for the TTY task (declared extern in tty.h). */ PUBLIC tty_t tty_table[NR_CONS+NR_RS_LINES+NR_PTYS]; PUBLIC int ccurrent; /* currently active console */ PUBLIC timer_t *tty_timers; /* queue of TTY timers */ PUBLIC clock_t tty_next_timeout; /* time that the next alarm is due */ PUBLIC struct machine machine; /* kernel environment variables */ /*===========================================================================* * tty_task * *===========================================================================*/ PUBLIC void main(void) { /* Main routine of the terminal task. */ message tty_mess; /* buffer for all incoming messages */ unsigned line; int s; char *types[] = {"task","driver","server", "user"}; register struct proc *rp; register tty_t *tp; /* Initialize the TTY driver. */ tty_init(); /* Get kernel environment (protected_mode, pc_at and ega are needed). */ if (OK != (s=sys_getmachine(&machine))) { panic("TTY","Couldn't obtain kernel environment.", s); } /* Final one-time keyboard initialization. */ kb_init_once(); printf("\n"); while (TRUE) { /* Check for and handle any events on any of the ttys. */ for (tp = FIRST_TTY; tp < END_TTY; tp++) { if (tp->tty_events) handle_events(tp); } /* Get a request message. */ receive(ANY, &tty_mess); /* First handle all kernel notification types that the TTY supports. * - An alarm went off, expire all timers and handle the events. * - A hardware interrupt also is an invitation to check for events. * - A new kernel message is available for printing. * - Reset the console on system shutdown. * Then see if this message is different from a normal device driver * request and should be handled separately. These extra functions * do not operate on a device, in constrast to the driver requests. */ switch (tty_mess.m_type) { case SYN_ALARM: /* fall through */ expire_timers(); /* run watchdogs of expired timers */ continue; /* contine to check for events */ case HARD_INT: { /* hardware interrupt notification */ if (tty_mess.NOTIFY_ARG & kbd_irq_set) kbd_interrupt(&tty_mess);/* fetch chars from keyboard */ #if NR_RS_LINES > 0 if (tty_mess.NOTIFY_ARG & rs_irq_set) rs_interrupt(&tty_mess);/* serial I/O */ #endif expire_timers(); /* run watchdogs of expired timers */ continue; /* contine to check for events */ } case SYS_SIG: { /* system signal */ sigset_t sigset = (sigset_t) tty_mess.NOTIFY_ARG; if (sigismember(&sigset, SIGKSTOP)) { cons_stop(); /* switch to primary console */ if (irq_hook_id != -1) { sys_irqdisable(&irq_hook_id); sys_irqrmpolicy(KEYBOARD_IRQ, &irq_hook_id); } } if (sigismember(&sigset, SIGTERM)) cons_stop(); if (sigismember(&sigset, SIGKMESS)) do_new_kmess(&tty_mess); continue; } case PANIC_DUMPS: /* allow panic dumps */ cons_stop(); /* switch to primary console */ do_panic_dumps(&tty_mess); continue; case DIAGNOSTICS: /* a server wants to print some */ do_diagnostics(&tty_mess); continue; case FKEY_CONTROL: /* (un)register a fkey observer */ do_fkey_ctl(&tty_mess); continue; default: /* should be a driver request */ ; /* do nothing; end switch */ } /* Only device requests should get to this point. All requests, * except DEV_STATUS, have a minor device number. Check this * exception and get the minor device number otherwise. */ if (tty_mess.m_type == DEV_STATUS) { do_status(&tty_mess); continue; } line = tty_mess.TTY_LINE; if ((line - CONS_MINOR) < NR_CONS) { tp = tty_addr(line - CONS_MINOR); } else if (line == LOG_MINOR) { tp = tty_addr(0); } else if ((line - RS232_MINOR) < NR_RS_LINES) { tp = tty_addr(line - RS232_MINOR + NR_CONS); } else if ((line - TTYPX_MINOR) < NR_PTYS) { tp = tty_addr(line - TTYPX_MINOR + NR_CONS + NR_RS_LINES); } else if ((line - PTYPX_MINOR) < NR_PTYS) { tp = tty_addr(line - PTYPX_MINOR + NR_CONS + NR_RS_LINES); if (tty_mess.m_type != DEV_IOCTL) { do_pty(tp, &tty_mess); continue; } } else { tp = NULL; } /* If the device doesn't exist or is not configured return ENXIO. */ if (tp == NULL || ! tty_active(tp)) { printf("Warning, TTY got illegal request %d from %d\n", tty_mess.m_type, tty_mess.m_source); tty_reply(TASK_REPLY, tty_mess.m_source, tty_mess.PROC_NR, ENXIO); continue; } /* Execute the requested device driver function. */ switch (tty_mess.m_type) { case DEV_READ: do_read(tp, &tty_mess); break; case DEV_WRITE: do_write(tp, &tty_mess); break; case DEV_IOCTL: do_ioctl(tp, &tty_mess); break; case DEV_OPEN: do_open(tp, &tty_mess); break; case DEV_CLOSE: do_close(tp, &tty_mess); break; case DEV_SELECT: do_select(tp, &tty_mess); break; case CANCEL: do_cancel(tp, &tty_mess); break; default: printf("Warning, TTY got unexpected request %d from %d (open is %d)\n", tty_mess.m_type, tty_mess.m_source, DEV_OPEN); tty_reply(TASK_REPLY, tty_mess.m_source, tty_mess.PROC_NR, EINVAL); } } } /*===========================================================================* * do_status * *===========================================================================*/ PRIVATE void do_status(m_ptr) message *m_ptr; { register struct tty *tp; int event_found; int status; int ops; /* Check for select or revive events on any of the ttys. If we found an, * event return a single status message for it. The FS will make another * call to see if there is more. */ event_found = 0; for (tp = FIRST_TTY; tp < END_TTY; tp++) { if ((ops = select_try(tp, tp->tty_select_ops)) && tp->tty_select_proc == m_ptr->m_source) { /* I/O for a selected minor device is ready. */ m_ptr->m_type = DEV_IO_READY; m_ptr->DEV_MINOR = tp->tty_index; m_ptr->DEV_SEL_OPS = ops; tp->tty_select_ops &= ~ops; /* unmark select event */ event_found = 1; break; } else if (tp->tty_inrevived && tp->tty_incaller == m_ptr->m_source) { /* Suspended request finished. Send a REVIVE. */ m_ptr->m_type = DEV_REVIVE; m_ptr->REP_PROC_NR = tp->tty_inproc; m_ptr->REP_STATUS = tp->tty_incum; tp->tty_inleft = tp->tty_incum = 0; tp->tty_inrevived = 0; /* unmark revive event */ event_found = 1; break; } else if (tp->tty_outrevived && tp->tty_outcaller == m_ptr->m_source) { /* Suspended request finished. Send a REVIVE. */ m_ptr->m_type = DEV_REVIVE; m_ptr->REP_PROC_NR = tp->tty_outproc; m_ptr->REP_STATUS = tp->tty_outcum; tp->tty_outcum = 0; tp->tty_outrevived = 0; /* unmark revive event */ event_found = 1; break; } } #if NR_PTYS > 0 if (!event_found) event_found = pty_status(m_ptr); #endif if (! event_found) { /* No events of interest were found. Return an empty message. */ m_ptr->m_type = DEV_NO_STATUS; } /* Almost done. Send back the reply message to the caller. */ if ((status = send(m_ptr->m_source, m_ptr)) != OK) { panic("TTY","send in do_status failed, status\n", status); } } /*===========================================================================* * do_read * *===========================================================================*/ PRIVATE void do_read(tp, m_ptr) register tty_t *tp; /* pointer to tty struct */ register message *m_ptr; /* pointer to message sent to the task */ { /* A process wants to read from a terminal. */ int r, status; phys_bytes phys_addr; /* Check if there is already a process hanging in a read, check if the * parameters are correct, do I/O. */ if (tp->tty_inleft > 0) { r = EIO; } else if (m_ptr->COUNT <= 0) { r = EINVAL; } else if (sys_umap(m_ptr->PROC_NR, D, (vir_bytes) m_ptr->ADDRESS, m_ptr->COUNT, &phys_addr) != OK) { r = EFAULT; } else { /* Copy information from the message to the tty struct. */ tp->tty_inrepcode = TASK_REPLY; tp->tty_incaller = m_ptr->m_source; tp->tty_inproc = m_ptr->PROC_NR; tp->tty_in_vir = (vir_bytes) m_ptr->ADDRESS; tp->tty_inleft = m_ptr->COUNT; if (!(tp->tty_termios.c_lflag & ICANON) && tp->tty_termios.c_cc[VTIME] > 0) { if (tp->tty_termios.c_cc[VMIN] == 0) { /* MIN & TIME specify a read timer that finishes the * read in TIME/10 seconds if no bytes are available. */ settimer(tp, TRUE); tp->tty_min = 1; } else { /* MIN & TIME specify an inter-byte timer that may * have to be cancelled if there are no bytes yet. */ if (tp->tty_eotct == 0) { settimer(tp, FALSE); tp->tty_min = tp->tty_termios.c_cc[VMIN]; } } } /* Anything waiting in the input buffer? Clear it out... */ in_transfer(tp); /* ...then go back for more. */ handle_events(tp); if (tp->tty_inleft == 0) { if (tp->tty_select_ops) select_retry(tp); return; /* already done */ } /* There were no bytes in the input queue available, so either suspend * the caller or break off the read if nonblocking. */ if (m_ptr->TTY_FLAGS & O_NONBLOCK) { r = EAGAIN; /* cancel the read */ tp->tty_inleft = tp->tty_incum = 0; } else { r = SUSPEND; /* suspend the caller */ tp->tty_inrepcode = REVIVE; } } tty_reply(TASK_REPLY, m_ptr->m_source, m_ptr->PROC_NR, r); if (tp->tty_select_ops) select_retry(tp); } /*===========================================================================* * do_write * *===========================================================================*/ PRIVATE void do_write(tp, m_ptr) register tty_t *tp; register message *m_ptr; /* pointer to message sent to the task */ { /* A process wants to write on a terminal. */ int r; phys_bytes phys_addr; /* Check if there is already a process hanging in a write, check if the * parameters are correct, do I/O. */ if (tp->tty_outleft > 0) { r = EIO; } else if (m_ptr->COUNT <= 0) { r = EINVAL; } else if (sys_umap(m_ptr->PROC_NR, D, (vir_bytes) m_ptr->ADDRESS, m_ptr->COUNT, &phys_addr) != OK) { r = EFAULT; } else { /* Copy message parameters to the tty structure. */ tp->tty_outrepcode = TASK_REPLY; tp->tty_outcaller = m_ptr->m_source; tp->tty_outproc = m_ptr->PROC_NR; tp->tty_out_vir = (vir_bytes) m_ptr->ADDRESS; tp->tty_outleft = m_ptr->COUNT; /* Try to write. */ handle_events(tp); if (tp->tty_outleft == 0) return; /* already done */ /* None or not all the bytes could be written, so either suspend the * caller or break off the write if nonblocking. */ if (m_ptr->TTY_FLAGS & O_NONBLOCK) { /* cancel the write */ r = tp->tty_outcum > 0 ? tp->tty_outcum : EAGAIN; tp->tty_outleft = tp->tty_outcum = 0; } else { r = SUSPEND; /* suspend the caller */ tp->tty_outrepcode = REVIVE; } } tty_reply(TASK_REPLY, m_ptr->m_source, m_ptr->PROC_NR, r); } /*===========================================================================* * do_ioctl * *===========================================================================*/ PRIVATE void do_ioctl(tp, m_ptr) register tty_t *tp; message *m_ptr; /* pointer to message sent to task */ { /* Perform an IOCTL on this terminal. Posix termios calls are handled * by the IOCTL system call */ int r; union { int i; } param; size_t size; /* Size of the ioctl parameter. */ switch (m_ptr->TTY_REQUEST) { case TCGETS: /* Posix tcgetattr function */ case TCSETS: /* Posix tcsetattr function, TCSANOW option */ case TCSETSW: /* Posix tcsetattr function, TCSADRAIN option */ case TCSETSF: /* Posix tcsetattr function, TCSAFLUSH option */ size = sizeof(struct termios); break; case TCSBRK: /* Posix tcsendbreak function */ case TCFLOW: /* Posix tcflow function */ case TCFLSH: /* Posix tcflush function */ case TIOCGPGRP: /* Posix tcgetpgrp function */ case TIOCSPGRP: /* Posix tcsetpgrp function */ size = sizeof(int); break; case TIOCGWINSZ: /* get window size (not Posix) */ case TIOCSWINSZ: /* set window size (not Posix) */ size = sizeof(struct winsize); break; case KIOCSMAP: /* load keymap (Minix extension) */ size = sizeof(keymap_t); break; case TIOCSFON: /* load font (Minix extension) */ size = sizeof(u8_t [8192]); break; case TCDRAIN: /* Posix tcdrain function -- no parameter */ default: size = 0; } r = OK; switch (m_ptr->TTY_REQUEST) { case TCGETS: /* Get the termios attributes. */ r = sys_vircopy(SELF, D, (vir_bytes) &tp->tty_termios, m_ptr->PROC_NR, D, (vir_bytes) m_ptr->ADDRESS, (vir_bytes) size); break; case TCSETSW: case TCSETSF: case TCDRAIN: if (tp->tty_outleft > 0) { /* Wait for all ongoing output processing to finish. */ tp->tty_iocaller = m_ptr->m_source; tp->tty_ioproc = m_ptr->PROC_NR; tp->tty_ioreq = m_ptr->REQUEST; tp->tty_iovir = (vir_bytes) m_ptr->ADDRESS; r = SUSPEND; break; } if (m_ptr->TTY_REQUEST == TCDRAIN) break; if (m_ptr->TTY_REQUEST == TCSETSF) tty_icancel(tp); /*FALL THROUGH*/ case TCSETS: /* Set the termios attributes. */ r = sys_vircopy( m_ptr->PROC_NR, D, (vir_bytes) m_ptr->ADDRESS, SELF, D, (vir_bytes) &tp->tty_termios, (vir_bytes) size); if (r != OK) break; setattr(tp); break; case TCFLSH: r = sys_vircopy( m_ptr->PROC_NR, D, (vir_bytes) m_ptr->ADDRESS, SELF, D, (vir_bytes) ¶m.i, (vir_bytes) size); if (r != OK) break; switch (param.i) { case TCIFLUSH: tty_icancel(tp); break; case TCOFLUSH: (*tp->tty_ocancel)(tp, 0); break; case TCIOFLUSH: tty_icancel(tp); (*tp->tty_ocancel)(tp, 0); break; default: r = EINVAL; } break; case TCFLOW: r = sys_vircopy( m_ptr->PROC_NR, D, (vir_bytes) m_ptr->ADDRESS, SELF, D, (vir_bytes) ¶m.i, (vir_bytes) size); if (r != OK) break; switch (param.i) { case TCOOFF: case TCOON: tp->tty_inhibited = (param.i == TCOOFF); tp->tty_events = 1; break; case TCIOFF: (*tp->tty_echo)(tp, tp->tty_termios.c_cc[VSTOP]); break; case TCION: (*tp->tty_echo)(tp, tp->tty_termios.c_cc[VSTART]); break; default: r = EINVAL; } break; case TCSBRK: if (tp->tty_break != NULL) (*tp->tty_break)(tp,0); break; case TIOCGWINSZ: r = sys_vircopy(SELF, D, (vir_bytes) &tp->tty_winsize, m_ptr->PROC_NR, D, (vir_bytes) m_ptr->ADDRESS, (vir_bytes) size); break; case TIOCSWINSZ: r = sys_vircopy( m_ptr->PROC_NR, D, (vir_bytes) m_ptr->ADDRESS, SELF, D, (vir_bytes) &tp->tty_winsize, (vir_bytes) size); /* SIGWINCH... */ break; case KIOCSMAP: /* Load a new keymap (only /dev/console). */ if (isconsole(tp)) r = kbd_loadmap(m_ptr); break; case TIOCSFON: /* Load a font into an EGA or VGA card (hs@hck.hr) */ if (isconsole(tp)) r = con_loadfont(m_ptr); break; /* These Posix functions are allowed to fail if _POSIX_JOB_CONTROL is * not defined. */ case TIOCGPGRP: case TIOCSPGRP: default: r = ENOTTY; } /* Send the reply. */ tty_reply(TASK_REPLY, m_ptr->m_source, m_ptr->PROC_NR, r); } /*===========================================================================* * do_open * *===========================================================================*/ PRIVATE void do_open(tp, m_ptr) register tty_t *tp; message *m_ptr; /* pointer to message sent to task */ { /* A tty line has been opened. Make it the callers controlling tty if * O_NOCTTY is *not* set and it is not the log device. 1 is returned if * the tty is made the controlling tty, otherwise OK or an error code. */ int r = OK; if (m_ptr->TTY_LINE == LOG_MINOR) { /* The log device is a write-only diagnostics device. */ if (m_ptr->COUNT & R_BIT) r = EACCES; } else { if (!(m_ptr->COUNT & O_NOCTTY)) { tp->tty_pgrp = m_ptr->PROC_NR; r = 1; } tp->tty_openct++; } tty_reply(TASK_REPLY, m_ptr->m_source, m_ptr->PROC_NR, r); } /*===========================================================================* * do_close * *===========================================================================*/ PRIVATE void do_close(tp, m_ptr) register tty_t *tp; message *m_ptr; /* pointer to message sent to task */ { /* A tty line has been closed. Clean up the line if it is the last close. */ if (m_ptr->TTY_LINE != LOG_MINOR && --tp->tty_openct == 0) { tp->tty_pgrp = 0; tty_icancel(tp); (*tp->tty_ocancel)(tp, 0); (*tp->tty_close)(tp, 0); tp->tty_termios = termios_defaults; tp->tty_winsize = winsize_defaults; setattr(tp); } tty_reply(TASK_REPLY, m_ptr->m_source, m_ptr->PROC_NR, OK); } /*===========================================================================* * do_cancel * *===========================================================================*/ PRIVATE void do_cancel(tp, m_ptr) register tty_t *tp; message *m_ptr; /* pointer to message sent to task */ { /* A signal has been sent to a process that is hanging trying to read or write. * The pending read or write must be finished off immediately. */ int proc_nr; int mode; /* Check the parameters carefully, to avoid cancelling twice. */ proc_nr = m_ptr->PROC_NR; mode = m_ptr->COUNT; if ((mode & R_BIT) && tp->tty_inleft != 0 && proc_nr == tp->tty_inproc) { /* Process was reading when killed. Clean up input. */ tty_icancel(tp); tp->tty_inleft = tp->tty_incum = 0; } if ((mode & W_BIT) && tp->tty_outleft != 0 && proc_nr == tp->tty_outproc) { /* Process was writing when killed. Clean up output. */ (*tp->tty_ocancel)(tp, 0); tp->tty_outleft = tp->tty_outcum = 0; } if (tp->tty_ioreq != 0 && proc_nr == tp->tty_ioproc) { /* Process was waiting for output to drain. */ tp->tty_ioreq = 0; } tp->tty_events = 1; tty_reply(TASK_REPLY, m_ptr->m_source, proc_nr, EINTR); } PUBLIC int select_try(struct tty *tp, int ops) { int ready_ops = 0; /* Special case. If line is hung up, no operations will block. * (and it can be seen as an exceptional condition.) */ if (tp->tty_termios.c_ospeed == B0) { ready_ops |= ops; } if (ops & SEL_RD) { /* will i/o not block on read? */ if (tp->tty_inleft > 0) { ready_ops |= SEL_RD; /* EIO - no blocking */ } else if (tp->tty_incount > 0) { /* Is a regular read possible? tty_incount * says there is data. But a read will only succeed * in canonical mode if a newline has been seen. */ if (!(tp->tty_termios.c_lflag & ICANON) || tp->tty_eotct > 0) { ready_ops |= SEL_RD; } } } if (ops & SEL_WR) { if (tp->tty_outleft > 0) ready_ops |= SEL_WR; else if ((*tp->tty_devwrite)(tp, 1)) ready_ops |= SEL_WR; } return ready_ops; } PUBLIC int select_retry(struct tty *tp) { if (select_try(tp, tp->tty_select_ops)) notify(tp->tty_select_proc); return OK; } /*===========================================================================* * handle_events * *===========================================================================*/ PUBLIC void handle_events(tp) tty_t *tp; /* TTY to check for events. */ { /* Handle any events pending on a TTY. These events are usually device * interrupts. * * Two kinds of events are prominent: * - a character has been received from the console or an RS232 line. * - an RS232 line has completed a write request (on behalf of a user). * The interrupt handler may delay the interrupt message at its discretion * to avoid swamping the TTY task. Messages may be overwritten when the * lines are fast or when there are races between different lines, input * and output, because MINIX only provides single buffering for interrupt * messages (in proc.c). This is handled by explicitly checking each line * for fresh input and completed output on each interrupt. */ char *buf; unsigned count; int status; do { tp->tty_events = 0; /* Read input and perform input processing. */ (*tp->tty_devread)(tp, 0); /* Perform output processing and write output. */ (*tp->tty_devwrite)(tp, 0); /* Ioctl waiting for some event? */ if (tp->tty_ioreq != 0) dev_ioctl(tp); } while (tp->tty_events); /* Transfer characters from the input queue to a waiting process. */ in_transfer(tp); /* Reply if enough bytes are available. */ if (tp->tty_incum >= tp->tty_min && tp->tty_inleft > 0) { if (tp->tty_inrepcode == REVIVE) { notify(tp->tty_incaller); tp->tty_inrevived = 1; } else { tty_reply(tp->tty_inrepcode, tp->tty_incaller, tp->tty_inproc, tp->tty_incum); tp->tty_inleft = tp->tty_incum = 0; } } if (tp->tty_select_ops) select_retry(tp); #if NR_PTYS > 0 if (ispty(tp)) select_retry_pty(tp); #endif } /*===========================================================================* * in_transfer * *===========================================================================*/ PRIVATE void in_transfer(tp) register tty_t *tp; /* pointer to terminal to read from */ { /* Transfer bytes from the input queue to a process reading from a terminal. */ int ch; int count; char buf[64], *bp; /* Force read to succeed if the line is hung up, looks like EOF to reader. */ if (tp->tty_termios.c_ospeed == B0) tp->tty_min = 0; /* Anything to do? */ if (tp->tty_inleft == 0 || tp->tty_eotct < tp->tty_min) return; bp = buf; while (tp->tty_inleft > 0 && tp->tty_eotct > 0) { ch = *tp->tty_intail; if (!(ch & IN_EOF)) { /* One character to be delivered to the user. */ *bp = ch & IN_CHAR; tp->tty_inleft--; if (++bp == bufend(buf)) { /* Temp buffer full, copy to user space. */ sys_vircopy(SELF, D, (vir_bytes) buf, tp->tty_inproc, D, tp->tty_in_vir, (vir_bytes) buflen(buf)); tp->tty_in_vir += buflen(buf); tp->tty_incum += buflen(buf); bp = buf; } } /* Remove the character from the input queue. */ if (++tp->tty_intail == bufend(tp->tty_inbuf)) tp->tty_intail = tp->tty_inbuf; tp->tty_incount--; if (ch & IN_EOT) { tp->tty_eotct--; /* Don't read past a line break in canonical mode. */ if (tp->tty_termios.c_lflag & ICANON) tp->tty_inleft = 0; } } if (bp > buf) { /* Leftover characters in the buffer. */ count = bp - buf; sys_vircopy(SELF, D, (vir_bytes) buf, tp->tty_inproc, D, tp->tty_in_vir, (vir_bytes) count); tp->tty_in_vir += count; tp->tty_incum += count; } /* Usually reply to the reader, possibly even if incum == 0 (EOF). */ if (tp->tty_inleft == 0) { if (tp->tty_inrepcode == REVIVE) { notify(tp->tty_incaller); tp->tty_inrevived = 1; } else { tty_reply(tp->tty_inrepcode, tp->tty_incaller, tp->tty_inproc, tp->tty_incum); tp->tty_inleft = tp->tty_incum = 0; } } } /*===========================================================================* * in_process * *===========================================================================*/ PUBLIC int in_process(tp, buf, count) register tty_t *tp; /* terminal on which character has arrived */ char *buf; /* buffer with input characters */ int count; /* number of input characters */ { /* Characters have just been typed in. Process, save, and echo them. Return * the number of characters processed. */ int ch, sig, ct; int timeset = FALSE; static unsigned char csize_mask[] = { 0x1F, 0x3F, 0x7F, 0xFF }; for (ct = 0; ct < count; ct++) { /* Take one character. */ ch = *buf++ & BYTE; /* Strip to seven bits? */ if (tp->tty_termios.c_iflag & ISTRIP) ch &= 0x7F; /* Input extensions? */ if (tp->tty_termios.c_lflag & IEXTEN) { /* Previous character was a character escape? */ if (tp->tty_escaped) { tp->tty_escaped = NOT_ESCAPED; ch |= IN_ESC; /* protect character */ } /* LNEXT (^V) to escape the next character? */ if (ch == tp->tty_termios.c_cc[VLNEXT]) { tp->tty_escaped = ESCAPED; rawecho(tp, '^'); rawecho(tp, '\b'); continue; /* do not store the escape */ } /* REPRINT (^R) to reprint echoed characters? */ if (ch == tp->tty_termios.c_cc[VREPRINT]) { reprint(tp); continue; } } /* _POSIX_VDISABLE is a normal character value, so better escape it. */ if (ch == _POSIX_VDISABLE) ch |= IN_ESC; /* Map CR to LF, ignore CR, or map LF to CR. */ if (ch == '\r') { if (tp->tty_termios.c_iflag & IGNCR) continue; if (tp->tty_termios.c_iflag & ICRNL) ch = '\n'; } else if (ch == '\n') { if (tp->tty_termios.c_iflag & INLCR) ch = '\r'; } /* Canonical mode? */ if (tp->tty_termios.c_lflag & ICANON) { /* Erase processing (rub out of last character). */ if (ch == tp->tty_termios.c_cc[VERASE]) { (void) back_over(tp); if (!(tp->tty_termios.c_lflag & ECHOE)) { (void) tty_echo(tp, ch); } continue; } /* Kill processing (remove current line). */ if (ch == tp->tty_termios.c_cc[VKILL]) { while (back_over(tp)) {} if (!(tp->tty_termios.c_lflag & ECHOE)) { (void) tty_echo(tp, ch); if (tp->tty_termios.c_lflag & ECHOK) rawecho(tp, '\n'); } continue; } /* EOF (^D) means end-of-file, an invisible "line break". */ if (ch == tp->tty_termios.c_cc[VEOF]) ch |= IN_EOT | IN_EOF; /* The line may be returned to the user after an LF. */ if (ch == '\n') ch |= IN_EOT; /* Same thing with EOL, whatever it may be. */ if (ch == tp->tty_termios.c_cc[VEOL]) ch |= IN_EOT; } /* Start/stop input control? */ if (tp->tty_termios.c_iflag & IXON) { /* Output stops on STOP (^S). */ if (ch == tp->tty_termios.c_cc[VSTOP]) { tp->tty_inhibited = STOPPED; tp->tty_events = 1; continue; } /* Output restarts on START (^Q) or any character if IXANY. */ if (tp->tty_inhibited) { if (ch == tp->tty_termios.c_cc[VSTART] || (tp->tty_termios.c_iflag & IXANY)) { tp->tty_inhibited = RUNNING; tp->tty_events = 1; if (ch == tp->tty_termios.c_cc[VSTART]) continue; } } } if (tp->tty_termios.c_lflag & ISIG) { /* Check for INTR (^?) and QUIT (^\) characters. */ if (ch == tp->tty_termios.c_cc[VINTR] || ch == tp->tty_termios.c_cc[VQUIT]) { sig = SIGINT; if (ch == tp->tty_termios.c_cc[VQUIT]) sig = SIGQUIT; sigchar(tp, sig); (void) tty_echo(tp, ch); continue; } } /* Is there space in the input buffer? */ if (tp->tty_incount == buflen(tp->tty_inbuf)) { /* No space; discard in canonical mode, keep in raw mode. */ if (tp->tty_termios.c_lflag & ICANON) continue; break; } if (!(tp->tty_termios.c_lflag & ICANON)) { /* In raw mode all characters are "line breaks". */ ch |= IN_EOT; /* Start an inter-byte timer? */ if (!timeset && tp->tty_termios.c_cc[VMIN] > 0 && tp->tty_termios.c_cc[VTIME] > 0) { settimer(tp, TRUE); timeset = TRUE; } } /* Perform the intricate function of echoing. */ if (tp->tty_termios.c_lflag & (ECHO|ECHONL)) ch = tty_echo(tp, ch); /* Save the character in the input queue. */ *tp->tty_inhead++ = ch; if (tp->tty_inhead == bufend(tp->tty_inbuf)) tp->tty_inhead = tp->tty_inbuf; tp->tty_incount++; if (ch & IN_EOT) tp->tty_eotct++; /* Try to finish input if the queue threatens to overflow. */ if (tp->tty_incount == buflen(tp->tty_inbuf)) in_transfer(tp); } return ct; } /*===========================================================================* * echo * *===========================================================================*/ PRIVATE int tty_echo(tp, ch) register tty_t *tp; /* terminal on which to echo */ register int ch; /* pointer to character to echo */ { /* Echo the character if echoing is on. Some control characters are echoed * with their normal effect, other control characters are echoed as "^X", * normal characters are echoed normally. EOF (^D) is echoed, but immediately * backspaced over. Return the character with the echoed length added to its * attributes. */ int len, rp; ch &= ~IN_LEN; if (!(tp->tty_termios.c_lflag & ECHO)) { if (ch == ('\n' | IN_EOT) && (tp->tty_termios.c_lflag & (ICANON|ECHONL)) == (ICANON|ECHONL)) (*tp->tty_echo)(tp, '\n'); return(ch); } /* "Reprint" tells if the echo output has been messed up by other output. */ rp = tp->tty_incount == 0 ? FALSE : tp->tty_reprint; if ((ch & IN_CHAR) < ' ') { switch (ch & (IN_ESC|IN_EOF|IN_EOT|IN_CHAR)) { case '\t': len = 0; do { (*tp->tty_echo)(tp, ' '); len++; } while (len < TAB_SIZE && (tp->tty_position & TAB_MASK) != 0); break; case '\r' | IN_EOT: case '\n' | IN_EOT: (*tp->tty_echo)(tp, ch & IN_CHAR); len = 0; break; default: (*tp->tty_echo)(tp, '^'); (*tp->tty_echo)(tp, '@' + (ch & IN_CHAR)); len = 2; } } else if ((ch & IN_CHAR) == '\177') { /* A DEL prints as "^?". */ (*tp->tty_echo)(tp, '^'); (*tp->tty_echo)(tp, '?'); len = 2; } else { (*tp->tty_echo)(tp, ch & IN_CHAR); len = 1; } if (ch & IN_EOF) while (len > 0) { (*tp->tty_echo)(tp, '\b'); len--; } tp->tty_reprint = rp; return(ch | (len << IN_LSHIFT)); } /*===========================================================================* * rawecho * *===========================================================================*/ PRIVATE void rawecho(tp, ch) register tty_t *tp; int ch; { /* Echo without interpretation if ECHO is set. */ int rp = tp->tty_reprint; if (tp->tty_termios.c_lflag & ECHO) (*tp->tty_echo)(tp, ch); tp->tty_reprint = rp; } /*===========================================================================* * back_over * *===========================================================================*/ PRIVATE int back_over(tp) register tty_t *tp; { /* Backspace to previous character on screen and erase it. */ u16_t *head; int len; if (tp->tty_incount == 0) return(0); /* queue empty */ head = tp->tty_inhead; if (head == tp->tty_inbuf) head = bufend(tp->tty_inbuf); if (*--head & IN_EOT) return(0); /* can't erase "line breaks" */ if (tp->tty_reprint) reprint(tp); /* reprint if messed up */ tp->tty_inhead = head; tp->tty_incount--; if (tp->tty_termios.c_lflag & ECHOE) { len = (*head & IN_LEN) >> IN_LSHIFT; while (len > 0) { rawecho(tp, '\b'); rawecho(tp, ' '); rawecho(tp, '\b'); len--; } } return(1); /* one character erased */ } /*===========================================================================* * reprint * *===========================================================================*/ PRIVATE void reprint(tp) register tty_t *tp; /* pointer to tty struct */ { /* Restore what has been echoed to screen before if the user input has been * messed up by output, or if REPRINT (^R) is typed. */ int count; u16_t *head; tp->tty_reprint = FALSE; /* Find the last line break in the input. */ head = tp->tty_inhead; count = tp->tty_incount; while (count > 0) { if (head == tp->tty_inbuf) head = bufend(tp->tty_inbuf); if (head[-1] & IN_EOT) break; head--; count--; } if (count == tp->tty_incount) return; /* no reason to reprint */ /* Show REPRINT (^R) and move to a new line. */ (void) tty_echo(tp, tp->tty_termios.c_cc[VREPRINT] | IN_ESC); rawecho(tp, '\r'); rawecho(tp, '\n'); /* Reprint from the last break onwards. */ do { if (head == bufend(tp->tty_inbuf)) head = tp->tty_inbuf; *head = tty_echo(tp, *head); head++; count++; } while (count < tp->tty_incount); } /*===========================================================================* * out_process * *===========================================================================*/ PUBLIC void out_process(tp, bstart, bpos, bend, icount, ocount) tty_t *tp; char *bstart, *bpos, *bend; /* start/pos/end of circular buffer */ int *icount; /* # input chars / input chars used */ int *ocount; /* max output chars / output chars used */ { /* Perform output processing on a circular buffer. *icount is the number of * bytes to process, and the number of bytes actually processed on return. * *ocount is the space available on input and the space used on output. * (Naturally *icount < *ocount.) The column position is updated modulo * the TAB size, because we really only need it for tabs. */ int tablen; int ict = *icount; int oct = *ocount; int pos = tp->tty_position; while (ict > 0) { switch (*bpos) { case '\7': break; case '\b': pos--; break; case '\r': pos = 0; break; case '\n': if ((tp->tty_termios.c_oflag & (OPOST|ONLCR)) == (OPOST|ONLCR)) { /* Map LF to CR+LF if there is space. Note that the * next character in the buffer is overwritten, so * we stop at this point. */ if (oct >= 2) { *bpos = '\r'; if (++bpos == bend) bpos = bstart; *bpos = '\n'; pos = 0; ict--; oct -= 2; } goto out_done; /* no space or buffer got changed */ } break; case '\t': /* Best guess for the tab length. */ tablen = TAB_SIZE - (pos & TAB_MASK); if ((tp->tty_termios.c_oflag & (OPOST|XTABS)) == (OPOST|XTABS)) { /* Tabs must be expanded. */ if (oct >= tablen) { pos += tablen; ict--; oct -= tablen; do { *bpos = ' '; if (++bpos == bend) bpos = bstart; } while (--tablen != 0); } goto out_done; } /* Tabs are output directly. */ pos += tablen; break; default: /* Assume any other character prints as one character. */ pos++; } if (++bpos == bend) bpos = bstart; ict--; oct--; } out_done: tp->tty_position = pos & TAB_MASK; *icount -= ict; /* [io]ct are the number of chars not used */ *ocount -= oct; /* *[io]count are the number of chars that are used */ } /*===========================================================================* * dev_ioctl * *===========================================================================*/ PRIVATE void dev_ioctl(tp) tty_t *tp; { /* The ioctl's TCSETSW, TCSETSF and TCDRAIN wait for output to finish to make * sure that an attribute change doesn't affect the processing of current * output. Once output finishes the ioctl is executed as in do_ioctl(). */ int result; if (tp->tty_outleft > 0) return; /* output not finished */ if (tp->tty_ioreq != TCDRAIN) { if (tp->tty_ioreq == TCSETSF) tty_icancel(tp); result = sys_vircopy(tp->tty_ioproc, D, tp->tty_iovir, SELF, D, (vir_bytes) &tp->tty_termios, (vir_bytes) sizeof(tp->tty_termios)); setattr(tp); } tp->tty_ioreq = 0; tty_reply(REVIVE, tp->tty_iocaller, tp->tty_ioproc, result); } /*===========================================================================* * setattr * *===========================================================================*/ PRIVATE void setattr(tp) tty_t *tp; { /* Apply the new line attributes (raw/canonical, line speed, etc.) */ u16_t *inp; int count; if (!(tp->tty_termios.c_lflag & ICANON)) { /* Raw mode; put a "line break" on all characters in the input queue. * It is undefined what happens to the input queue when ICANON is * switched off, a process should use TCSAFLUSH to flush the queue. * Keeping the queue to preserve typeahead is the Right Thing, however * when a process does use TCSANOW to switch to raw mode. */ count = tp->tty_eotct = tp->tty_incount; inp = tp->tty_intail; while (count > 0) { *inp |= IN_EOT; if (++inp == bufend(tp->tty_inbuf)) inp = tp->tty_inbuf; --count; } } /* Inspect MIN and TIME. */ settimer(tp, FALSE); if (tp->tty_termios.c_lflag & ICANON) { /* No MIN & TIME in canonical mode. */ tp->tty_min = 1; } else { /* In raw mode MIN is the number of chars wanted, and TIME how long * to wait for them. With interesting exceptions if either is zero. */ tp->tty_min = tp->tty_termios.c_cc[VMIN]; if (tp->tty_min == 0 && tp->tty_termios.c_cc[VTIME] > 0) tp->tty_min = 1; } if (!(tp->tty_termios.c_iflag & IXON)) { /* No start/stop output control, so don't leave output inhibited. */ tp->tty_inhibited = RUNNING; tp->tty_events = 1; } /* Setting the output speed to zero hangs up the phone. */ if (tp->tty_termios.c_ospeed == B0) sigchar(tp, SIGHUP); /* Set new line speed, character size, etc at the device level. */ (*tp->tty_ioctl)(tp, 0); } /*===========================================================================* * tty_reply * *===========================================================================*/ PUBLIC void tty_reply(code, replyee, proc_nr, status) int code; /* TASK_REPLY or REVIVE */ int replyee; /* destination address for the reply */ int proc_nr; /* to whom should the reply go? */ int status; /* reply code */ { /* Send a reply to a process that wanted to read or write data. */ message tty_mess; tty_mess.m_type = code; tty_mess.REP_PROC_NR = proc_nr; tty_mess.REP_STATUS = status; if ((status = send(replyee, &tty_mess)) != OK) { panic("TTY","tty_reply failed, status\n", status); } } /*===========================================================================* * sigchar * *===========================================================================*/ PUBLIC void sigchar(tp, sig) register tty_t *tp; int sig; /* SIGINT, SIGQUIT, SIGKILL or SIGHUP */ { /* Process a SIGINT, SIGQUIT or SIGKILL char from the keyboard or SIGHUP from * a tty close, "stty 0", or a real RS-232 hangup. MM will send the signal to * the process group (INT, QUIT), all processes (KILL), or the session leader * (HUP). */ int status; if (tp->tty_pgrp != 0) if (OK != (status = sys_kill(tp->tty_pgrp, sig))) panic("TTY","Error, call to sys_kill failed", status); if (!(tp->tty_termios.c_lflag & NOFLSH)) { tp->tty_incount = tp->tty_eotct = 0; /* kill earlier input */ tp->tty_intail = tp->tty_inhead; (*tp->tty_ocancel)(tp, 0); /* kill all output */ tp->tty_inhibited = RUNNING; tp->tty_events = 1; } } /*===========================================================================* * tty_icancel * *===========================================================================*/ PRIVATE void tty_icancel(tp) register tty_t *tp; { /* Discard all pending input, tty buffer or device. */ tp->tty_incount = tp->tty_eotct = 0; tp->tty_intail = tp->tty_inhead; (*tp->tty_icancel)(tp, 0); } /*===========================================================================* * tty_init * *===========================================================================*/ PRIVATE void tty_init() { /* Initialize tty structure and call device initialization routines. */ register tty_t *tp; int s; struct sigaction sigact; /* Initialize the terminal lines. */ for (tp = FIRST_TTY,s=0; tp < END_TTY; tp++,s++) { tp->tty_index = s; tmr_inittimer(&tp->tty_tmr); tp->tty_intail = tp->tty_inhead = tp->tty_inbuf; tp->tty_min = 1; tp->tty_termios = termios_defaults; tp->tty_icancel = tp->tty_ocancel = tp->tty_ioctl = tp->tty_close = tty_devnop; if (tp < tty_addr(NR_CONS)) { scr_init(tp); tp->tty_minor = CONS_MINOR + s; } else if (tp < tty_addr(NR_CONS+NR_RS_LINES)) { rs_init(tp); tp->tty_minor = RS232_MINOR + s-NR_CONS; } else { pty_init(tp); tp->tty_minor = s + TTYPX_MINOR + s-(NR_CONS+RS232_MINOR); } } } /*===========================================================================* * tty_timed_out * *===========================================================================*/ PRIVATE void tty_timed_out(timer_t *tp) { /* This timer has expired. Set the events flag, to force processing. */ tty_t *tty_ptr; tty_ptr = &tty_table[tmr_arg(tp)->ta_int]; tty_ptr->tty_min = 0; /* force read to succeed */ tty_ptr->tty_events = 1; } /*===========================================================================* * expire_timers * *===========================================================================*/ PRIVATE void expire_timers(void) { /* A synchronous alarm message was received. Check if there are any expired * timers. Possibly set the event flag and reschedule another alarm. */ clock_t now; /* current time */ int s; /* Get the current time to compare the timers against. */ if ((s=getuptime(&now)) != OK) panic("TTY","Couldn't get uptime from clock.", s); /* Scan the queue of timers for expired timers. This dispatch the watchdog * functions of expired timers. Possibly a new alarm call must be scheduled. */ tmrs_exptimers(&tty_timers, now, NULL); if (tty_timers == NULL) tty_next_timeout = TMR_NEVER; else { /* set new sync alarm */ tty_next_timeout = tty_timers->tmr_exp_time; if ((s=sys_setalarm(tty_next_timeout, 1)) != OK) panic("TTY","Couldn't set synchronous alarm.", s); } } /*===========================================================================* * settimer * *===========================================================================*/ PRIVATE void settimer(tty_ptr, enable) tty_t *tty_ptr; /* line to set or unset a timer on */ int enable; /* set timer if true, otherwise unset */ { clock_t now; /* current time */ clock_t exp_time; int s; /* Get the current time to calculate the timeout time. */ if ((s=getuptime(&now)) != OK) panic("TTY","Couldn't get uptime from clock.", s); if (enable) { exp_time = now + tty_ptr->tty_termios.c_cc[VTIME] * (HZ/10); /* Set a new timer for enabling the TTY events flags. */ tmrs_settimer(&tty_timers, &tty_ptr->tty_tmr, exp_time, tty_timed_out, NULL); } else { /* Remove the timer from the active and expired lists. */ tmrs_clrtimer(&tty_timers, &tty_ptr->tty_tmr, NULL); } /* Now check if a new alarm must be scheduled. This happens when the front * of the timers queue was disabled or reinserted at another position, or * when a new timer was added to the front. */ if (tty_timers == NULL) tty_next_timeout = TMR_NEVER; else if (tty_timers->tmr_exp_time != tty_next_timeout) { tty_next_timeout = tty_timers->tmr_exp_time; if ((s=sys_setalarm(tty_next_timeout, 1)) != OK) panic("TTY","Couldn't set synchronous alarm.", s); } } /*===========================================================================* * tty_devnop * *===========================================================================*/ PUBLIC int tty_devnop(tp, try) tty_t *tp; int try; { /* Some functions need not be implemented at the device level. */ } /*===========================================================================* * do_select * *===========================================================================*/ PRIVATE void do_select(tp, m_ptr) register tty_t *tp; /* pointer to tty struct */ register message *m_ptr; /* pointer to message sent to the task */ { int ops, ready_ops = 0, watch; ops = m_ptr->PROC_NR & (SEL_RD|SEL_WR|SEL_ERR); watch = (m_ptr->PROC_NR & SEL_NOTIFY) ? 1 : 0; ready_ops = select_try(tp, ops); if (!ready_ops && ops && watch) { tp->tty_select_ops |= ops; tp->tty_select_proc = m_ptr->m_source; } tty_reply(TASK_REPLY, m_ptr->m_source, m_ptr->PROC_NR, ready_ops); return; }