Members/e085722/Cerium: old/framebuffer/cp

comparison old/framebuffer/cp_vt.c @ 0:04e28d8d3c6f

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author	Daiki KINJYO <e085722@ie.u-ryukyu.ac.jp>
date	Mon, 08 Nov 2010 01:23:25 +0900
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+:04e28d8d3c6f
+// cp_vt.c
+//
+// Copyright (c) 2006, Mike Acton <macton@cellperformance.com>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
+// documentation files (the "Software"), to deal in the Software without restriction, including without
+// limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+// the Software, and to permit persons to whom the Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or substantial
+// portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
+// LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO
+// EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+// AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
+// OR OTHER DEALINGS IN THE SOFTWARE.
+// NOTES:
+// From http://www.linuxjournal.com/article/2597
+//
+//     "Console ttys are used when the keyboard and monitor are directly connected to the system without running
+//     the X Window System. Since you can have several virtual consoles, the devices are tty0 through tty63. In
+//     theory you can have 64 virtual consoles, but most people use only a few. The device /dev/console is
+//     identical to tty0 and is needed for historical reasons. If your system lets you log in on consoles 1
+//     through 6, then when you run X Windows System, X uses console 7, so you'll need /dev/tty1 through /dev/
+//     tty7 on your system. I recommend having files up through /dev/tty12. For more information on using
+//     virtual consoles, see the article Keyboards, Consoles and VT Cruising by John Fisk in the November 1996
+//     issue of Linux Journal"
+#include <stdio.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <linux/vt.h>
+#include <linux/kd.h>
+#include "cp_vt.h"
+static inline const char*
+select_error_str( int existing_error, const char* const existing_error_str, int new_error, const char* const new_error_str )
+{
+// Only report the first error found - any error that follows is probably just a cascading effect.
+const char* error_str = (char*)( (~(intptr_t)existing_error & (intptr_t)new_error & (intptr_t)new_error_str)
+|  ((intptr_t)existing_error & (intptr_t)existing_error_str) );
+return (error_str);
+}
+int
+cp_vt_open_graphics(cp_vt* restrict vt)
+{
+const char*    error_str      = NULL;
+int            error          = 0;
+// Open the current tty
+// From http://tldp.org/HOWTO/Text-Terminal-HOWTO-6.html#ss6.3
+// (An excellent overview by David S. Lawyer)
+//
+//     "In Linux the PC monitor is usually called the console and has several device special files associated
+//     with it: vc/0 (tty0), vc/1 (tty1), vc/2 (tty2), etc. When you log in you are on vc/1. To go to vc/2
+//     (on the same screen) press down the 2 keys Alt(left)-F3. For vc/3 use Left Alt-F3, etc. These (vc/1,
+//     vc/2, vc/3, etc.) are called "virtual terminals". vc/0 (tty0) is just an alias for the current virtual
+//     terminal and it's where messages from the system are sent. Thus messages from the system will be seen
+//     on the console (monitor) regardless of which virtual terminal it is displaying."
+const int   cur_tty                = open( "/dev/tty0", O_RDWR );
+const int   open_cur_tty_error     = (cur_tty >> ((sizeof(int)*8)-1));
+const char* open_cur_tty_error_str = "Could not open /dev/tty0. Check permissions.";
+error_str = select_error_str( error, error_str, open_cur_tty_error, open_cur_tty_error_str );
+error     = error | open_cur_tty_error;
+// From: http://www.linuxjournal.com/article/2783
+// (A little out of date, but a nice primer.)
+//
+//     "VT_GETSTATE returns the state of all VT's in the kernel in the structure:
+//
+//         struct vt_stat {
+//               ushort v_active;
+//               ushort v_signal;
+//               ushort v_state;
+//          };
+//
+//      v_active        the currently active VT
+//      v_state         mask of all the opened VT's
+//
+//      v_active holds the number of the active VT (starting from 1), while v_state
+//      holds a mask where there is a 1 for each VT that has been opened by some process.
+//      Note that VT 0 is always opened in this scenario, since it refers to the current VT.
+//
+//      Bugs:
+//      The v_signal member is unsupported."
+struct vt_stat  vts;
+const int   get_state_error     = ioctl( cur_tty, VT_GETSTATE, &vts );
+const char* get_state_error_str = "VT_GETSTATE failed on /dev/tty0";
+error_str = select_error_str( error, error_str, get_state_error, get_state_error_str );
+error     = error | get_state_error;
+vt->prev_tty_ndx = vts.v_active;
+// From: http://opensolaris.org/os/project/vconsole/vt.7i.txt
+// (Close enough to Linux and a pretty good source of documentation.)
+//
+// "VT_OPENQRY
+//     This call is used to find an available VT.    The argu-
+//     ment to the    ioctl is a pointer to an integer.  The integer
+//     will be filled in with the number of the first avail-
+//     able VT that no other process has open (and    hence, is
+//     available to be opened).  If there are no available
+//     VTs, then -1 will be filled in."
+const int   open_query_error     = ioctl( cur_tty, VT_OPENQRY, &vt->tty_ndx);
+const char* open_query_error_str = "No open ttys available";
+error_str = select_error_str( error, error_str, open_query_error, open_query_error_str );
+error     = error | open_query_error;
+const int   close_cur_tty_error     = close( cur_tty );
+const char* close_cur_tty_error_str = "Could not close parent tty";
+error_str = select_error_str( error, error_str, close_cur_tty_error, close_cur_tty_error_str );
+error     = error | close_cur_tty_error;
+char tty_file_name[11];
+(void)snprintf( tty_file_name, 11, "/dev/tty%d", vt->tty_ndx );
+const int   tty                = open( tty_file_name, O_RDWR );
+const int   open_tty_error     = (cur_tty >> ((sizeof(int)*8)-1));
+const char* open_tty_error_str = "Could not open tty";
+error_str = select_error_str( error, error_str, open_tty_error, open_tty_error_str );
+error     = error | open_tty_error;
+vt->tty = tty;
+// From: http://opensolaris.org/os/project/vconsole/vt.7i.txt
+// (Close enough to Linux and a pretty good source of documentation.)
+//
+// "VT_ACTIVATE
+//    This call has the effect of making the VT specified in
+//    the argument the active VT. The VT manager will cause
+//    a switch to occur in the same manner as if a hotkey had
+//    initiated the switch.  If the specified VT is not open
+//    or does not exist the call will fail and errno will be
+//    set to ENXIO."
+//
+// "VT_WAITACTIVE
+//    If the specified VT is already active, this call
+//    returns immediately. Otherwise, it will sleep until
+//    the specified VT becomes active, at which point it will
+//    return."
+const int   activate_tty_error     = ioctl( vt->tty, VT_ACTIVATE, vt->tty_ndx );
+const char* activate_tty_error_str = "Could not activate tty";
+error_str = select_error_str( error, error_str, activate_tty_error, activate_tty_error_str );
+error     = error | activate_tty_error;
+#if 0
+const int   waitactive_tty_error     = ioctl( vt->tty, VT_WAITACTIVE, vt->tty_ndx );
+const char* waitactive_tty_error_str = "Could not switch to tty";
+error_str = select_error_str( error, error_str, waitactive_tty_error, waitactive_tty_error_str );
+error     = error | waitactive_tty_error;
+#endif
+// From: http://opensolaris.org/os/project/vconsole/vt.7i.txt
+// (Close enough to Linux and a pretty good source of documentation.)
+//
+//  "KDSETMODE
+//   This call is used to set the text/graphics mode to the VT.
+//
+//      KD_TEXT indicates that console text will be displayed on the screen
+//      with this VT. Normally KD_TEXT is combined with VT_AUTO mode for
+//      text console terminals, so that the console text display will
+//      automatically be saved and restored on the hot key screen switches.
+//
+//      KD_GRAPHICS indicates that the user/application, usually Xserver,
+//      will have direct control of the display for this VT in graphics
+//      mode. Normally KD_GRAPHICS is combined with VT_PROCESS mode for
+//      this VT indicating direct control of the display in graphics mode.
+//      In this mode, all writes to this VT using the write system call are
+//      ignored, and the user is responsible for saving and restoring the
+//      display on the hot key screen switches."
+// Save the current VT mode. This is most likely KD_TEXT.
+const int   kdgetmode_error     = ioctl( vt->tty, KDGETMODE, &vt->prev_kdmode );
+const char* kdgetmode_error_str = "Could not get mode for tty";
+error_str = select_error_str( error, error_str, kdgetmode_error, kdgetmode_error_str );
+error     = error | kdgetmode_error;
+// Set VT to GRAPHICS (user draw) mode
+const int   kdsetmode_graphics_error     = ioctl( vt->tty, KDSETMODE, KD_GRAPHICS );
+const char* kdsetmode_graphics_error_str = "Could not set graphics mode for tty";
+error_str = select_error_str( error, error_str, kdsetmode_graphics_error, kdsetmode_graphics_error_str );
+error     = error | kdsetmode_graphics_error;
+//
+// Not bothering with VT_PROCESS, VT_AUTO is fine for our purposes.
+//
+// If vt blanking is active, for example when running this program from a remote terminal,
+// setting KD_GRAPHICS will not disable the blanking. Reset to KD_TEXT from KD_GRAPHICS will
+// force disable blanking. Then return to KD_GRAPHICS for drawing.
+//
+// Note: KD_TEXT (default) to KD_TEXT will do nothing, so blanking will not be disable unless
+// the mode is changing. i.e. the initial set to KD_GRAPHICS above is useful.
+const int   kdsetmode_text_error     = ioctl( vt->tty, KDSETMODE, KD_TEXT );
+const char* kdsetmode_text_error_str = "Could not set text mode for tty";
+error_str = select_error_str( error, error_str, kdsetmode_text_error, kdsetmode_text_error_str );
+error     = error | kdsetmode_text_error;
+const int   kdsetmode_graphics_reset_error     = ioctl( vt->tty, KDSETMODE, KD_GRAPHICS );
+const char* kdsetmode_graphics_reset_error_str = "Could not reset graphics mode for tty";
+error_str = select_error_str( error, error_str, kdsetmode_graphics_reset_error, kdsetmode_graphics_reset_error_str );
+error     = error | kdsetmode_graphics_reset_error;
+if ( error == -1 )
+{
+printf("ERROR: vt_graphics_open: %s\n",error_str);
+return (-1);
+}
+return (0);
+}
+int
+cp_vt_close(cp_vt* restrict vt)
+{
+const char*    error_str      = NULL;
+int            error          = 0;
+// Reset previous mode on tty (likely KD_TEXT)
+const int   kdsetmode_error     = ioctl( vt->tty, KDSETMODE, vt->prev_kdmode );
+const char* kdsetmode_error_str = "Could not reset previous mode for tty";
+error_str = select_error_str( error, error_str, kdsetmode_error, kdsetmode_error_str );
+error     = error | kdsetmode_error;
+// Restore previous tty
+const int   activate_tty_error     = ioctl( vt->tty, VT_ACTIVATE, vt->prev_tty_ndx );
+const char* activate_tty_error_str = "Could not activate previous tty";
+error_str = select_error_str( error, error_str, activate_tty_error, activate_tty_error_str );
+error     = error | activate_tty_error;
+const int   waitactive_tty_error     = ioctl( vt->tty, VT_WAITACTIVE, vt->prev_tty_ndx );
+const char* waitactive_tty_error_str = "Could not switch to previous tty";
+error_str = select_error_str( error, error_str, waitactive_tty_error, waitactive_tty_error_str );
+error     = error | waitactive_tty_error;
+// Close tty
+const int   close_tty_error     = close( vt->tty );
+const char* close_tty_error_str = "Could not close tty";
+error_str = select_error_str( error, error_str, close_tty_error, close_tty_error_str );
+error     = error | close_tty_error;
+if ( error == -1 )
+{
+printf("ERROR: vt_close: %s\n",error_str);
+return (-1);
+}
+return (0);
+}

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comparison old/framebuffer/cp_vt.c @ 0:04e28d8d3c6f