console.c

一个开源著名的TDE编辑器源代码

/*
 * All video and keyboard functions were gathered into one file.
 *
 * In version 3.2, this file was split into 3 sections:  1) unix curses
 * made to look and feel like a PC, 2) our PC hardware specific stuff,
 * and 3) hardware independent stuff.
 *
 * This file contains the keyboard and video i/o stuff.  Most of this stuff
 * is specific to the PC hardware, but it should be easily modified when
 * porting to other platforms.  With a few key functions written in
 * assembly, we have fairly fast video performance and good keyboard control.
 * Incidentally, the commented C code in the functions perform the same
 * function as the assembly code.  In earlier versions of TDE, I didn't
 * update the commented C code when I changed the assembly code.  The
 * C and assembly should be equivalent in version 2.2.
 *
 * Although using a curses type package would be more portable, curses
 * can be slow on PCs.  Let's keep our video and keyboard routines in
 * assembly.  I feel the need for speed.
 *
 * Being that TDE 2.2 keeps an accurate count of characters in each line, we
 * can allow the user to enter any ASCII or Extended ASCII key.
 *
 * Determining the video adapter type on the PC requires a function.  In
 *  TDE, that function is:
 *
 *                void video_config( struct vcfg *cfg )
 *
 * video_config( ) is based on Appendix C in _Programmer's Guide to
 *  PC & PS/2 Video Systems_ by Richard Wilton.
 *
 * See:
 *
 *   Richard Wilton, _Programmer's Guide to PC & PS/2 Video Systems_,
 *    Microsoft Press, Redmond, Washington, 1987, Appendix C, pp 511-521.
 *    ISBN 1-55615-103-9.
 *
 *
 * New editor name:  TDE, the Thomson-Davis Editor.
 * Author:           Frank Davis
 * Date:             June 5, 1991, version 1.0
 * Date:             July 29, 1991, version 1.1
 * Date:             October 5, 1991, version 1.2
 * Date:             January 20, 1992, version 1.3
 * Date:             February 17, 1992, version 1.4
 * Date:             April 1, 1992, version 1.5
 * Date:             June 5, 1992, version 2.0
 * Date:             October 31, 1992, version 2.1
 * Date:             April 1, 1993, version 2.2
 * Date:             June 5, 1993, version 3.0
 * Date:             August 29, 1993 version 3.1
 * Date:             November 13, version 3.2
 * Date:             June 5, 1994, version 4.0
 * Date:             December 5, 1998, version 5.0 (jmh)
 *
 * This code is released into the public domain, Frank Davis.
 * You may distribute it freely.
 */


#include "tdestr.h"
#include "common.h"
#include "define.h"
#include "tdefunc.h"
#define __dj_include_pc_h_      /* don't include pc.h and its getkey */
#include <bios.h>               /* for direct BIOS keyboard input */
#include <sys/movedata.h>       /* for reading the BIOS memory */
#include <inlines/pc.h>         /* for inportb to access the keyboard */
#include <sys/exceptn.h>


static unsigned long display_address;   /* address of display memory */

static int  s_cbrk;             /* original control-break checking flag */
static int  stdoutput;          /* stdout for redirected shelling */

static int  kbd_active = TRUE;          /* should my INT09 be used? */
volatile
static unsigned int  kbd_shift = 0;     /* the actual shift states */
static unsigned char kbd_bios_shift,    /* the fake BIOS shift states */
                     kbd_scancode,      /* the hardware scan code */
                     kbd_prefix = 0,    /* detect prefixed codes */
                     kbd_menu;          /* the Menu key */
static _go32_dpmi_seginfo kbd_old_int;  /* the original INT09 */
static _go32_dpmi_seginfo kbd_new_int;  /* my new INT09 */

#define KBD_INT (_go32_info_block.master_interrupt_controller_base + 1)

/*
 * Convert a row and column co-ordinate into a screen memory address.
 */
#define SCREEN_PTR( row, col ) \
   (display_address + ((row) * g_display.ncols + (col)) * 2)


static void bright_background( void );
static int  shadow_width( int, int, int );
static void kbd_int( void );


/*
 * Name:    console_init
 * Purpose: initialise the console (video and keyboard)
 * Author:  Jason Hood
 * Date:    October 23, 2002
 * Passed:  cfg:  pointer to hold video config data
 * Notes:   initialises both video and keyboard hardware.
 *          moved some stuff from main.c into here.
 */
void console_init( struct vcfg *cfg )
{
   /*
    * May as well make use of additional video memory.  There may be a
    * problem with hi-res text modes (greater than 100x80, 132x61), but
    * since I've been using page 1 since 5.0 without complaints, I guess
    * it's not a problem, after all. (Whilst I can set 132x66, I never do,
    * at least not for any period of time. :) )
    */
   page( 1 );
   video_config( cfg );

   __djgpp_set_ctrl_c( 0 );             /* turn off Ctrl-C breaking */
   s_cbrk = getcbrk( );                 /* disable DOS Ctrl-Break checking */
   setcbrk( 0 );

   /*
    * Setup and install the keyboard hardware interrupt.
    *
    * The method of finding the length of a function by defining another
    * function after it doesn't work in newer GCCs (functions get reordered),
    * so just use GDB to disassemble it and find its length that way.
    */
   _go32_dpmi_lock_code( kbd_int, 428 );
   _go32_dpmi_lock_data( (void *)&kbd_shift, sizeof(kbd_shift) );
   _go32_dpmi_lock_data( (void *)&kbd_bios_shift, sizeof(kbd_bios_shift) );
   _go32_dpmi_lock_data( (void *)&kbd_scancode, sizeof(kbd_scancode) );
   _go32_dpmi_lock_data( (void *)&kbd_prefix, sizeof(kbd_prefix) );
   _go32_dpmi_get_protected_mode_interrupt_vector( KBD_INT, &kbd_old_int );
   kbd_new_int.pm_selector = _go32_my_cs();
   kbd_new_int.pm_offset = (unsigned long)kbd_int;
   _go32_dpmi_chain_protected_mode_interrupt_vector( KBD_INT, &kbd_new_int );
}


/*
 * Name:    console_suspend
 * Purpose: temporarily shutdown the console
 * Author:  Jason Hood
 * Date:    October 23, 2002
 * Notes:   readies the console for a shell
 */
void console_suspend( void )
{
   page( 0 );
   set_cursor_size( g_display.curses_cursor );
   if (g_display.adapter != MDA)
      set_overscan_color( g_display.old_overscan );
   kbd_active = FALSE;
   setcbrk( s_cbrk );

   /*
    * If output has been redirected then put it back to the screen for the
    * shell and restore it afterwards.
    */
   if (g_status.output_redir) {
      stdoutput = dup( fileno( stdout ) );
      freopen( STDFILE, "w", stdout );
   }

   __djgpp_exception_toggle( );
}


/*
 * Name:    console_resume
 * Purpose: restore the console
 * Author:  Jason Hood
 * Date:    October 23, 2002
 * Notes:   restores the console for TDE
 */
void console_resume( int pause )
{
   __djgpp_exception_toggle( );

   if (g_status.output_redir)
      dup2( stdoutput, fileno( stdout ) );

   kbd_active = TRUE;
   kbd_shift = 0;
   setcbrk( 0 );

   if (pause)
      getkey( );

   page( 1 );
   bright_background( );
   if (g_display.adapter != MDA)
      set_overscan_color( Color( Overscan ) );
}


/*
 * Name:    console_exit
 * Purpose: resets the console
 * Author:  Jason Hood
 * Date:    October 23, 2002
 * Notes:   resets the console after TDE has finished
 */
void console_exit( void )
{
   setcbrk( s_cbrk );

   /*
    * reset the cursor size and unload the keyboard utility
    */
   set_cursor_size( g_display.curses_cursor );
   _go32_dpmi_set_protected_mode_interrupt_vector( KBD_INT, &kbd_old_int );

   page( 0 );                   /* back to page 0 for DOS */
}


/*
 *   BIOS Data Areas
 *
 *   See:
 *
 *      IBM Corp., _Technical Reference:  Personal Computer AT_,
 *      Boca Raton, Florida, 1984, IBM part no. 1502494,
 *      pp 5-29 thru 5-32.
 *
 *  These addresses, variable names, types, and descriptions are directly
 *   from the IBM AT Technical Reference manual, BIOS listing, copyright IBM.
 *
 *   Address  Name           Type   Description
 *   0x0449   CRT_MODE       Byte   Current CRT mode
 *   0x044a   CRT_COLS       Word   Number columns on screen
 *   0x044c   CRT_LEN        Word   length of regen buffer, video buffer, bytes
 *   0x044e   CRT_START      Word   Starting address of regen buffer
 *   0x0450   CURSOR_POSN    Word   cursor for each of up to 8 pages.
 *   0x0460   CURSOR_MODE    Word   current cursor mode setting.
 *   0x0462   ACTIVE_PAGE    Byte   Current page
 *   0x0463   ADDR_6845      Word   base address for active display card
 *   0x0465   CRT_MODE_SET   Byte   current mode of display card
 *   0x0466   CRT_PALETTE    Byte   overscan color for CGA, EGA, and VGA.
 *   0x0467   io_rom_init    Word   Pointer to optional i/o rom init routine
 *   0x0469   io_rom_seg     Word   Pointer to io rom segment
 *   0x046b   intr_flag      Byte   Flag to indicate an interrupt happened
 *   0x046c   timer_low      Word   Low word of timer count
 *   0x046e   timer_high     Word   High word of timer count
 *   0x0470   timer_ofl      Byte   Timer has rolled over since last count
 *   0x0471   bios_break     Byte   Bit 7 = 1 if Break Key has been hit
 *   0x0472   reset_flag     Word   Word = 1234h if keyboard reset underway
 *   0x0484   ROWS           Byte   Number of displayed character rows - 1
 *   0x0485   POINTS         Word   Height of character matrix
 *   0x0487   INFO           Byte   EGA and VGA display data
 *   0x0488   INFO_3         Byte   Configuration switches for EGA and VGA
 *   0x0489   flags          Byte   Miscellaneous flags
 *   0x0496   kb_flag_3      Byte   Additional keyboard flag
 *   0x048A   DCC            Byte   Display Combination Code
 *   0x04A8   SAVE_PTR       Dword  Pointer to BIOS save area
 */
void video_config( struct vcfg *cfg )
{

struct LOWMEMVID
{
   unsigned char  vidmode;              /* 0x449 */
   unsigned short scrwid;               /* 0x44A */
   unsigned short scrlen;               /* 0x44C */
   unsigned short scroff;               /* 0x44E */
   struct   LOCATE
   {
      unsigned char col;
      unsigned char row;
   } __attribute__ ((packed)) csrpos[8];/* 0x450 */
   unsigned short csrsize;              /* 0x460 */
   unsigned char  page;                 /* 0x462 */
   unsigned short addr_6845;            /* 0x463 */
   unsigned char  crt_mode_set;         /* 0x465 */
   unsigned char  crt_palette;          /* 0x466 */
   unsigned char  system_stuff[29];     /* 0x467 */
   unsigned char  rows;                 /* 0x484 */
   unsigned short points;               /* 0x485 */
   unsigned char  ega_info;             /* 0x487 */
   unsigned char  info_3;               /* 0x488 */
   unsigned char  skip[13];             /* 0x489 */
   unsigned char  kb_flag_3;            /* 0x496 */
} __attribute__ ((packed)) vid;

union REGS in, out;
unsigned char temp, active_display;

   /*
    * Move system information into our video structure.
    */
   dosmemget( 0x449, sizeof( vid ), &vid );

   /*
    * this next code was contributed by Jim Derr <[e-mail]>
    * jmh 991024: slightly modified, since I moved it from hw_initialize().
    */
   cfg->cols = vid.scrwid;
   cfg->rows = vid.rows + 1;
   if (cfg->rows == 1)
      cfg->rows = 25;

   in.w.ax =  0x1a00;
   int86( VIDEO_INT, &in, &out );
   temp = out.h.al;
   active_display = out.h.bl;
   if (temp == 0x1a && (active_display == 7 || active_display == 8))
      g_display.adapter = VGA;
   else {
      in.h.ah =  0x12;
      in.h.bl =  0x10;
      int86( VIDEO_INT, &in, &out );
      if (out.h.bl != 0x10) {         /* EGA */
         if (vid.ega_info & 0x08)
            g_display.adapter = vid.addr_6845 == 0x3d4 ? CGA : MDA;
         else
            g_display.adapter = EGA;
      } else if (vid.addr_6845 == 0x3d4)
         g_display.adapter = CGA;
      else
         g_display.adapter = MDA;
   }

   /*
    * jmh 990213: Due to the config file being read after the cursor style
    *             variable, just set cursor sizes.
    */
   if (g_display.adapter == CGA || g_display.adapter == EGA) {
      g_display.cursor[SMALL_CURSOR]  = 0x0607;
      g_display.cursor[MEDIUM_CURSOR] = 0x0407;
      g_display.cursor[LARGE_CURSOR]  = 0x0007;
   } else {
      g_display.cursor[SMALL_CURSOR]  = 0x0b0c;
      g_display.cursor[MEDIUM_CURSOR] = 0x070b;
      g_display.cursor[LARGE_CURSOR]  = 0x000b;
   }
   /*
    * jmh 990213: remember original cursor size.
    */
   g_display.curses_cursor = vid.csrsize;

   /* jmh - added the vid.scroff for proper page offset */
   display_address = 0xb8000ul + vid.scroff;
   cfg->color = (vid.addr_6845 == 0x3D4);
   if (!cfg->color)
      display_address -= 0x8000;        /* monochrome is at 0xb0000 */

   /*
    * let's save the overscan color
    */
   g_display.old_overscan = vid.crt_palette;

   /*
    * Get keyboard type.  Since there is no interrupt that determines
    * keyboard type, use this method.  Look at bit 4 in keyboard flag3.
    * This method is not always foolproof on clones.
    */
   if ((vid.kb_flag_3 & 0x10) != 0)
      mode.enh_kbd = TRUE;
   else
      mode.enh_kbd = FALSE;

   /*
    * jmh 991023: determine the width of the right edge of the shadow.