/*
 * DOS interrupt 2fh handler
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "ldt.h"
#include "drive.h"
#include "msdos.h"
#include "miscemu.h"
#include "module.h"
#include "stddebug.h"
/* #define DEBUG_INT */
#include "debug.h"

  /* base WPROCS.DLL ordinal number for VxDs */
#define VXD_BASE 400

static void do_int2f_16( CONTEXT *context );

/**********************************************************************
 *	    INT_Int2fHandler
 *
 * Handler for int 2fh (multiplex).
 */
void WINAPI INT_Int2fHandler( CONTEXT *context )
{
    switch(AH_reg(context))
    {
    case 0x10:
        AL_reg(context) = 0xff; /* share is installed */
        break;

    case 0x15: /* mscdex */
        do_mscdex(context);
        break;

    case 0x16:
        do_int2f_16( context );
        break;

    case 0x4a:
        switch(AL_reg(context))
        {
	case 0x10:  /* smartdrv */
	    break;  /* not installed */
        case 0x11:  /* dblspace */
            break;  /* not installed */
        case 0x12:  /* realtime compression interface */
            break;  /* not installed */
        default:
            INT_BARF( context, 0x2f );
        }
        break;
    case 0xb7:  /* append */
        AL_reg(context) = 0; /* not installed */
        break;
    default:
        INT_BARF( context, 0x2f );
        break;
    }
}


/**********************************************************************
 *	    do_int2f_16
 */
static void do_int2f_16( CONTEXT *context )
{
    DWORD addr;

    switch(AL_reg(context))
    {
    case 0x00:  /* Windows enhanced mode installation check */
        AX_reg(context) = (GetWinFlags() & WF_ENHANCED) ?
                                                  LOWORD(GetVersion16()) : 0;
        break;
	
    case 0x0a:  /* Get Windows version and type */
        AX_reg(context) = 0;
        BX_reg(context) = (LOWORD(GetVersion16()) << 8) |
                          (LOWORD(GetVersion16()) >> 8);
        CX_reg(context) = (GetWinFlags() & WF_ENHANCED) ? 3 : 2;
        break;

    case 0x80:  /* Release time-slice */
	AL_reg(context) = 0;
	/* FIXME: We need to do something that lets some other process run
	   here.  */
	sleep(0);
        break;

    case 0x81: /* Begin critical section.  */
        /* FIXME? */
        break;

    case 0x82: /* End critical section.  */
        /* FIXME? */
        break;

    case 0x83:  /* Return Current Virtual Machine ID */
        /* Virtual Machines are usually created/destroyed when Windows runs
         * DOS programs. Since we never do, we are always in the System VM.
         * According to Ralf Brown's Interrupt List, never return 0. But it
         * seems to work okay (returning 0), just to be sure we return 1.
         */
	BX_reg(context) = 1; /* VM 1 is probably the System VM */
	break;

    case 0x84:  /* Get device API entry point */
        addr = (DWORD)MODULE_GetEntryPoint( GetModuleHandle16("WPROCS"),
                                            VXD_BASE + BX_reg(context) );
        if (!addr)  /* not supported */
        {
	    fprintf( stderr,"Application attempted to access VxD %04x\n",
                     BX_reg(context) );
	    fprintf( stderr,"This device is not known to Wine.");
	    fprintf( stderr,"Expect a failure now\n");
        }
	ES_reg(context) = SELECTOROF(addr);
	DI_reg(context) = OFFSETOF(addr);
	break;

    case 0x86:  /* DPMI detect mode */
        AX_reg(context) = 0;  /* Running under DPMI */
        break;

    /* FIXME: is this right?  Specs say that this should only be callable
       in real (v86) mode which we never enter.  */
    case 0x87: /* DPMI installation check */
        {
	    SYSTEM_INFO si;

	    GetSystemInfo(&si);
	    AX_reg(context) = 0x0000; /* DPMI Installed */
            BX_reg(context) = 0x0001; /* 32bits available */
            CL_reg(context) = si.wProcessorLevel;
            DX_reg(context) = 0x005a; /* DPMI major/minor 0.90 */
            SI_reg(context) = 0;      /* # of para. of DOS extended private data */
            ES_reg(context) = 0;      /* ES:DI is DPMI switch entry point */
            DI_reg(context) = 0;
            break;
        }
    case 0x8a:  /* DPMI get vendor-specific API entry point. */
	/* The 1.0 specs say this should work with all 0.9 hosts.  */
	break;

    default:
        INT_BARF( context, 0x2f );
    }
}

void do_mscdex( CONTEXT *context )
{
    int drive, count;
    char *p;

    switch(AL_reg(context))
    {
        case 0x00: /* Installation check */
            /* Count the number of contiguous CDROM drives
             */
            for (drive = count = 0; drive < MAX_DOS_DRIVES; drive++)
            {
                if (DRIVE_GetType(drive) == TYPE_CDROM)
                {
                    while (DRIVE_GetType(drive + count) == TYPE_CDROM) count++;
                    break;
                }
            }

            BX_reg(context) = count;
            CX_reg(context) = (drive < MAX_DOS_DRIVES) ? drive : 0;
            break;

        case 0x0B: /* drive check */
            AX_reg(context) = (DRIVE_GetType(CX_reg(context)) == TYPE_CDROM);
            BX_reg(context) = 0xADAD;
            break;

        case 0x0C: /* get version */
            BX_reg(context) = 0x020a;
            break;

        case 0x0D: /* get drive letters */
            p = PTR_SEG_OFF_TO_LIN(ES_reg(context), BX_reg(context));
            memset( p, 0, MAX_DOS_DRIVES );
            for (drive = 0; drive < MAX_DOS_DRIVES; drive++)
            {
                if (DRIVE_GetType(drive) == TYPE_CDROM) *p++ = drive;
            }
            break;

        default:
            fprintf(stderr, "Unimplemented MSCDEX function 0x%02.2X.\n", AL_reg(context));
            break;
    }
}