TTY: use libchardriver; clean up

- writing to a PTY master side blocks if there is not already a
  blocked reader on the slave side, and select now reflects this;
- internally, TTY now uses a test based on "caller != NONE" rather
  than "grant != GRANT_INVALID" to identify whether a call is
  currently ongoing;
- "offset" fields have been removed as they equal the corresponding
  "cum" fields;
- improved variable typing and function naming here and there;
- various other small fixes.

Change-Id: I6b51452888942e864b4e034e8c8490576184a23e

include/minix/Makefile

@@ -18,7 +18,7 @@ INCS+=	acpi.h audio_fw.h bitmap.h \
 	reboot.h rs.h safecopies.h sched.h sef.h sffs.h \
 	sound.h spin.h sys_config.h sysinfo.h \
 	syslib.h sysutil.h termios.h timers.h type.h \
-	tty.h u64.h usb.h usb_ch9.h vbox.h \
+	u64.h usb.h usb_ch9.h vbox.h \
 	vboxfs.h vboxif.h vboxtype.h vm.h \
 	vfsif.h vtreefs.h libminixfs.h netsock.h \
 	virtio.h

include/minix/com.h

@@ -1275,7 +1275,6 @@
 
 
 #define TTY_FKEY_CONTROL	(TTY_RQ_BASE + 1) /* control an F-key at TTY */
-#define OLD_FKEY_CONTROL	98  	/* previously used for TTY_FKEY_CONTROL */
 #  define FKEY_REQUEST	     m2_i1	/* request to perform at TTY */
 #  define    FKEY_MAP		10	/* observe function key */
 #  define    FKEY_UNMAP		11	/* stop observing function key */

include/minix/tty.h

@@ -1,28 +0,0 @@
-
-#ifndef _MINIX_TTY_H
-#define _MINIX_TTY_H
-
-#include <sys/types.h>
-
-#define TTYMAGIC	0xb105
-
-/* A struct that the tty driver can use to pass values to the boot monitor.
- * Currently only the value of the origin of the first vty (console), so the
- * boot monitor can properly display it when panicing (tty isn't scheduled
- * to switch to the first vty). It's written at the end of video memory
- * (video memory base + video memory size - sizeof(struct boot_tty_info).
- */
-
-struct boot_tty_info {
-	u16_t	reserved[30];	/* reserved, set to 0 */
-	u16_t	consorigin;	/* origin in video memory of console */
-	u16_t	conscursor;	/* position of cursor of console */
-	u16_t   flags;		/* flags indicating which fields are valid */
-	u16_t	magic;		/* magic number indicating struct is valid */
-};
-
-#define BTIF_CONSORIGIN	0x01	/* consorigin is set */
-#define BTIF_CONSCURSOR	0x02	/* conscursor is set */
-
-#endif
-

include/sys/ioc_tty.h

@@ -22,7 +22,6 @@
 #define	TIOCSWINSZ	_IOW('T', 17, struct winsize)
 #define	TIOCGPGRP	_IOW('T', 18, int)
 #define	TIOCSPGRP	_IOW('T', 19, int)
-#define TIOCSFON_OLD	_IOW('T', 20, u8_t [8192])
 #define TIOCSFON	_IOW_BIG(1, u8_t [8192])
 
 /* Keyboard ioctls. */