/*
 *                   XFree86 int10 module
 *   execute BIOS int 10h calls in x86 real mode environment
 *                 Copyright 1999 Egbert Eich
 */
#ifdef HAVE_XORG_CONFIG_H
#include <xorg-config.h>
#endif

#include <string.h>
#include <stdlib.h>

#include "xf86.h"
#include "xf86_OSproc.h"
#include "compiler.h"
#include "xf86Pci.h"
#define _INT10_PRIVATE
#if 0
#include "int10Defines.h"
#endif
#include "xf86int10.h"

#define REG pInt

typedef enum {
    OPT_NOINT10,
    OPT_INIT_PRIMARY,
} INT10Opts;

static const OptionInfoRec INT10Options[] = {
    {OPT_NOINT10, "NoINT10", OPTV_BOOLEAN, {0}, FALSE},
    {OPT_INIT_PRIMARY, "InitPrimary", OPTV_BOOLEAN, {0}, FALSE},
    {-1, NULL, OPTV_NONE, {0}, FALSE},
};

#ifdef DEBUG
void
dprint(unsigned long start, unsigned long size)
{
    int i, j;
    char *c = (char *) start;

    for (j = 0; j < (size >> 4); j++) {
        char *d = c;

        ErrorF("\n0x%lx:  ", (unsigned long) c);
        for (i = 0; i < 16; i++)
            ErrorF("%2.2x ", (unsigned char) (*(c++)));
        c = d;
        for (i = 0; i < 16; i++) {
            ErrorF("%c", ((((CARD8) (*c)) > 32) && (((CARD8) (*c)) < 128)) ?
                   (unsigned char) (*(c)) : '.');
            c++;
        }
    }
    ErrorF("\n");
}
#endif

#ifndef _PC
/*
 * here we are really paranoid about faking a "real"
 * BIOS. Most of this information was pulled from
 * dosemu.
 */
void
setup_int_vect(xf86Int10InfoPtr pInt)
{
    int i;

    /* let the int vects point to the SYS_BIOS seg */
    for (i = 0; i < 0x80; i++) {
        MEM_WW(pInt, i << 2, 0);
        MEM_WW(pInt, (i << 2) + 2, SYS_BIOS >> 4);
    }

    reset_int_vect(pInt);
    /* font tables default location (int 1F) */
    MEM_WW(pInt, 0x1f << 2, 0xfa6e);

    /* int 11 default location (Get Equipment Configuration) */
    MEM_WW(pInt, 0x11 << 2, 0xf84d);
    /* int 12 default location (Get Conventional Memory Size) */
    MEM_WW(pInt, 0x12 << 2, 0xf841);
    /* int 15 default location (I/O System Extensions) */
    MEM_WW(pInt, 0x15 << 2, 0xf859);
    /* int 1A default location (RTC, PCI and others) */
    MEM_WW(pInt, 0x1a << 2, 0xff6e);
    /* int 05 default location (Bound Exceeded) */
    MEM_WW(pInt, 0x05 << 2, 0xff54);
    /* int 08 default location (Double Fault) */
    MEM_WW(pInt, 0x08 << 2, 0xfea5);
    /* int 13 default location (Disk) */
    MEM_WW(pInt, 0x13 << 2, 0xec59);
    /* int 0E default location (Page Fault) */
    MEM_WW(pInt, 0x0e << 2, 0xef57);
    /* int 17 default location (Parallel Port) */
    MEM_WW(pInt, 0x17 << 2, 0xefd2);
    /* fdd table default location (int 1e) */
    MEM_WW(pInt, 0x1e << 2, 0xefc7);

    /* Set Equipment flag to VGA */
    i = MEM_RB(pInt, 0x0410) & 0xCF;
    MEM_WB(pInt, 0x0410, i);
    /* XXX Perhaps setup more of the BDA here.  See also int42(0x00). */
}
#endif

int
setup_system_bios(void *base_addr)
{
    char *base = (char *) base_addr;

    /*
     * we trap the "industry standard entry points" to the BIOS
     * and all other locations by filling them with "hlt"
     * TODO: implement hlt-handler for these
     */
    memset(base, 0xf4, 0x10000);

    /* set bios date */
    strcpy(base + 0x0FFF5, "06/11/99");
    /* set up eisa ident string */
    strcpy(base + 0x0FFD9, "PCI_ISA");
    /* write system model id for IBM-AT */
    *((unsigned char *) (base + 0x0FFFE)) = 0xfc;

    return 1;
}

void
reset_int_vect(xf86Int10InfoPtr pInt)
{
    /*
     * This table is normally located at 0xF000:0xF0A4.  However, int 0x42,
     * function 0 (Mode Set) expects it (or a copy) somewhere in the bottom
     * 64kB.  Note that because this data doesn't survive POST, int 0x42 should
     * only be used during EGA/VGA BIOS initialisation.
     */
    static const CARD8 VideoParms[] = {
        /* Timing for modes 0x00 & 0x01 */
        0x38, 0x28, 0x2d, 0x0a, 0x1f, 0x06, 0x19, 0x1c,
        0x02, 0x07, 0x06, 0x07, 0x00, 0x00, 0x00, 0x00,
        /* Timing for modes 0x02 & 0x03 */
        0x71, 0x50, 0x5a, 0x0a, 0x1f, 0x06, 0x19, 0x1c,
        0x02, 0x07, 0x06, 0x07, 0x00, 0x00, 0x00, 0x00,
        /* Timing for modes 0x04, 0x05 & 0x06 */
        0x38, 0x28, 0x2d, 0x0a, 0x7f, 0x06, 0x64, 0x70,
        0x02, 0x01, 0x06, 0x07, 0x00, 0x00, 0x00, 0x00,
        /* Timing for mode 0x07 */
        0x61, 0x50, 0x52, 0x0f, 0x19, 0x06, 0x19, 0x19,
        0x02, 0x0d, 0x0b, 0x0c, 0x00, 0x00, 0x00, 0x00,
        /* Display page lengths in little endian order */
        0x00, 0x08,             /* Modes 0x00 and 0x01 */
        0x00, 0x10,             /* Modes 0x02 and 0x03 */
        0x00, 0x40,             /* Modes 0x04 and 0x05 */
        0x00, 0x40,             /* Modes 0x06 and 0x07 */
        /* Number of columns for each mode */
        40, 40, 80, 80, 40, 40, 80, 80,
        /* CGA Mode register value for each mode */
        0x2c, 0x28, 0x2d, 0x29, 0x2a, 0x2e, 0x1e, 0x29,
        /* Padding */
        0x00, 0x00, 0x00, 0x00
    };
    int i;

    for (i = 0; i < sizeof(VideoParms); i++)
        MEM_WB(pInt, i + (0x1000 - sizeof(VideoParms)), VideoParms[i]);
    MEM_WW(pInt, 0x1d << 2, 0x1000 - sizeof(VideoParms));
    MEM_WW(pInt, (0x1d << 2) + 2, 0);

    MEM_WW(pInt, 0x10 << 2, 0xf065);
    MEM_WW(pInt, (0x10 << 2) + 2, SYS_BIOS >> 4);
    MEM_WW(pInt, 0x42 << 2, 0xf065);
    MEM_WW(pInt, (0x42 << 2) + 2, SYS_BIOS >> 4);
    MEM_WW(pInt, 0x6D << 2, 0xf065);
    MEM_WW(pInt, (0x6D << 2) + 2, SYS_BIOS >> 4);
}

void
set_return_trap(xf86Int10InfoPtr pInt)
{
    /*
     * Here we set the exit condition:  We return when we encounter
     * 'hlt' (=0xf4), which we locate at address 0x600 in x86 memory.
     */
    MEM_WB(pInt, 0x0600, 0xf4);

    /*
     * Allocate a segment for the stack
     */
    xf86Int10AllocPages(pInt, 1, &pInt->stackseg);
}

void *
xf86HandleInt10Options(ScrnInfoPtr pScrn, int entityIndex)
{
    EntityInfoPtr pEnt = xf86GetEntityInfo(entityIndex);
    OptionInfoPtr options = NULL;

    if (pEnt->device) {
        pointer configOptions = NULL;

        /* Check if xf86CollectOptions() has already been called */
        if (((pEnt->index < 0) ||
             !pScrn || !(configOptions = pScrn->options)) && pEnt->device)
            configOptions = pEnt->device->options;

        if (configOptions) {
            if (!(options = (OptionInfoPtr) malloc(sizeof(INT10Options))))
                return NULL;

            (void) memcpy(options, INT10Options, sizeof(INT10Options));
            xf86ProcessOptions(pScrn->scrnIndex, configOptions, options);
        }
    }
    free(pEnt);

    return options;
}

Bool
int10skip(const void *options)
{
    Bool noint10 = FALSE;

    if (!options)
        return FALSE;

    xf86GetOptValBool(options, OPT_NOINT10, &noint10);
    return noint10;
}

Bool
int10_check_bios(int scrnIndex, int codeSeg, const unsigned char *vbiosMem)
{
    int size;

    if ((codeSeg & 0x1f) ||     /* Not 512-byte aligned otherwise */
        ((codeSeg << 4) < V_BIOS) || ((codeSeg << 4) >= SYS_SIZE))
        return FALSE;

    if ((*vbiosMem != 0x55) || (*(vbiosMem + 1) != 0xAA) || !*(vbiosMem + 2))
        return FALSE;

    size = *(vbiosMem + 2) * 512;

    if ((size + (codeSeg << 4)) > SYS_SIZE)
        return FALSE;

    if (bios_checksum(vbiosMem, size))
        xf86DrvMsg(scrnIndex, X_INFO, "Bad V_BIOS checksum\n");

    return TRUE;
}

Bool
initPrimary(const void *options)
{
    Bool initPrimary = FALSE;

    if (!options)
        return FALSE;

    xf86GetOptValBool(options, OPT_INIT_PRIMARY, &initPrimary);
    return initPrimary;
}

BusType
xf86int10GetBiosLocationType(const xf86Int10InfoPtr pInt)
{
    BusType location_type;

    EntityInfoPtr pEnt = xf86GetEntityInfo(pInt->entityIndex);

    location_type = pEnt->location.type;
    free(pEnt);

    return location_type;
}

#define CHECK_V_SEGMENT_RANGE(x)   \
    if (((x) << 4) < V_BIOS) { \
	xf86DrvMsg(pInt->pScrn->scrnIndex, X_ERROR, \
		   "V_BIOS address 0x%lx out of range\n", \
		   (unsigned long)(x) << 4); \
	return FALSE; \
    }

Bool
xf86int10GetBiosSegment(xf86Int10InfoPtr pInt, void *base)
{
    unsigned i;
    int cs = ~0;
    int segments[4];

    segments[0] = MEM_RW(pInt, (0x10 << 2) + 2);
    segments[1] = MEM_RW(pInt, (0x42 << 2) + 2);
    segments[2] = V_BIOS >> 4;
    segments[3] = ~0;

    for (i = 0; segments[i] != ~0; i++) {
        unsigned char *vbiosMem;

        cs = segments[i];

        CHECK_V_SEGMENT_RANGE(cs);
        vbiosMem = (unsigned char *) base + (cs << 4);
        if (int10_check_bios(pInt->pScrn->scrnIndex, cs, vbiosMem)) {
            break;
        }
    }

    if (segments[i] == ~0) {
        xf86DrvMsg(pInt->pScrn->scrnIndex, X_ERROR, "No V_BIOS found\n");
        return FALSE;
    }

    xf86DrvMsg(pInt->pScrn->scrnIndex, X_INFO, "Primary V_BIOS segment is: 0x%lx\n",
               (unsigned long) cs);

    pInt->BIOSseg = cs;
    return TRUE;
}