boxv_io.h

/*****************************************************************************

Copyright (c) 2012-2022  Michal Necasek

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
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The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

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*****************************************************************************/

#include <conio.h>  /* For port I/O prototypes. */

/* The 16-bit compiler does not do inpd(). We have to do it ourselves.
 * NB: It might be OK to trash the high bits of EAX but better be safe.
 */
/* Warning: Destroys high bits of EAX. */
unsigned long inpd( unsigned port );
#pragma aux inpd =      \
    ".386"              \
    "push   eax"        \
    "in     eax, dx"    \
    "mov    dx, ax"     \
    "shr    eax, 16"    \
    "xchg   bx, ax"     \
    "pop    eax"        \
    "xchg   bx, ax"     \
    "xchg   ax, dx"     \
    parm [dx] value [dx ax] modify [bx] nomemory;

static void vid_outb( void *cx, unsigned port, unsigned val )
{
    outp( port, val );
}

static void vid_outw( void *cx, unsigned port, unsigned val )
{
    outpw( port, val );
}

static unsigned vid_inb( void *cx, unsigned port )
{
    return( inp( port ) );
}

static unsigned vid_inw( void *cx, unsigned port )
{
    return( inpw( port ) );
}