vga.c

qemu虚拟机代码

/*
 * QEMU VGA Emulator.
 * 
 * Copyright (c) 2003 Fabrice Bellard
 * 
 * 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.
 */
#include "vl.h"
#include "vga_int.h"

//#define DEBUG_VGA
//#define DEBUG_VGA_MEM
//#define DEBUG_VGA_REG

//#define DEBUG_BOCHS_VBE

/* force some bits to zero */
const uint8_t sr_mask[8] = {
    (uint8_t)~0xfc,
    (uint8_t)~0xc2,
    (uint8_t)~0xf0,
    (uint8_t)~0xc0,
    (uint8_t)~0xf1,
    (uint8_t)~0xff,
    (uint8_t)~0xff,
    (uint8_t)~0x00,
};

const uint8_t gr_mask[16] = {
    (uint8_t)~0xf0, /* 0x00 */
    (uint8_t)~0xf0, /* 0x01 */
    (uint8_t)~0xf0, /* 0x02 */
    (uint8_t)~0xe0, /* 0x03 */
    (uint8_t)~0xfc, /* 0x04 */
    (uint8_t)~0x84, /* 0x05 */
    (uint8_t)~0xf0, /* 0x06 */
    (uint8_t)~0xf0, /* 0x07 */
    (uint8_t)~0x00, /* 0x08 */
    (uint8_t)~0xff, /* 0x09 */
    (uint8_t)~0xff, /* 0x0a */
    (uint8_t)~0xff, /* 0x0b */
    (uint8_t)~0xff, /* 0x0c */
    (uint8_t)~0xff, /* 0x0d */
    (uint8_t)~0xff, /* 0x0e */
    (uint8_t)~0xff, /* 0x0f */
};

#define cbswap_32(__x) \
((uint32_t)( \
		(((uint32_t)(__x) & (uint32_t)0x000000ffUL) << 24) | \
		(((uint32_t)(__x) & (uint32_t)0x0000ff00UL) <<  8) | \
		(((uint32_t)(__x) & (uint32_t)0x00ff0000UL) >>  8) | \
		(((uint32_t)(__x) & (uint32_t)0xff000000UL) >> 24) ))

#ifdef WORDS_BIGENDIAN
#define PAT(x) cbswap_32(x)
#else
#define PAT(x) (x)
#endif

#ifdef WORDS_BIGENDIAN
#define BIG 1
#else
#define BIG 0
#endif

#ifdef WORDS_BIGENDIAN
#define GET_PLANE(data, p) (((data) >> (24 - (p) * 8)) & 0xff)
#else
#define GET_PLANE(data, p) (((data) >> ((p) * 8)) & 0xff)
#endif

static const uint32_t mask16[16] = {
    PAT(0x00000000),
    PAT(0x000000ff),
    PAT(0x0000ff00),
    PAT(0x0000ffff),
    PAT(0x00ff0000),
    PAT(0x00ff00ff),
    PAT(0x00ffff00),
    PAT(0x00ffffff),
    PAT(0xff000000),
    PAT(0xff0000ff),
    PAT(0xff00ff00),
    PAT(0xff00ffff),
    PAT(0xffff0000),
    PAT(0xffff00ff),
    PAT(0xffffff00),
    PAT(0xffffffff),
};

#undef PAT

#ifdef WORDS_BIGENDIAN
#define PAT(x) (x)
#else
#define PAT(x) cbswap_32(x)
#endif

static const uint32_t dmask16[16] = {
    PAT(0x00000000),
    PAT(0x000000ff),
    PAT(0x0000ff00),
    PAT(0x0000ffff),
    PAT(0x00ff0000),
    PAT(0x00ff00ff),
    PAT(0x00ffff00),
    PAT(0x00ffffff),
    PAT(0xff000000),
    PAT(0xff0000ff),
    PAT(0xff00ff00),
    PAT(0xff00ffff),
    PAT(0xffff0000),
    PAT(0xffff00ff),
    PAT(0xffffff00),
    PAT(0xffffffff),
};

static const uint32_t dmask4[4] = {
    PAT(0x00000000),
    PAT(0x0000ffff),
    PAT(0xffff0000),
    PAT(0xffffffff),
};

static uint32_t expand4[256];
static uint16_t expand2[256];
static uint8_t expand4to8[16];

VGAState *vga_state;
int vga_io_memory;

static void vga_screen_dump(void *opaque, const char *filename);

static uint32_t vga_ioport_read(void *opaque, uint32_t addr)
{
    VGAState *s = opaque;
    int val, index;

    /* check port range access depending on color/monochrome mode */
    if ((addr >= 0x3b0 && addr <= 0x3bf && (s->msr & MSR_COLOR_EMULATION)) ||
        (addr >= 0x3d0 && addr <= 0x3df && !(s->msr & MSR_COLOR_EMULATION))) {
        val = 0xff;
    } else {
        switch(addr) {
        case 0x3c0:
            if (s->ar_flip_flop == 0) {
                val = s->ar_index;
            } else {
                val = 0;
            }
            break;
        case 0x3c1:
            index = s->ar_index & 0x1f;
            if (index < 21) 
                val = s->ar[index];
            else
                val = 0;
            break;
        case 0x3c2:
            val = s->st00;
            break;
        case 0x3c4:
            val = s->sr_index;
            break;
        case 0x3c5:
            val = s->sr[s->sr_index];
#ifdef DEBUG_VGA_REG
            printf("vga: read SR%x = 0x%02x\n", s->sr_index, val);
#endif
            break;
        case 0x3c7:
            val = s->dac_state;
            break;
	case 0x3c8:
	    val = s->dac_write_index;
	    break;
        case 0x3c9:
            val = s->palette[s->dac_read_index * 3 + s->dac_sub_index];
            if (++s->dac_sub_index == 3) {
                s->dac_sub_index = 0;
                s->dac_read_index++;
            }
            break;
        case 0x3ca:
            val = s->fcr;
            break;
        case 0x3cc:
            val = s->msr;
            break;
        case 0x3ce:
            val = s->gr_index;
            break;
        case 0x3cf:
            val = s->gr[s->gr_index];
#ifdef DEBUG_VGA_REG
            printf("vga: read GR%x = 0x%02x\n", s->gr_index, val);
#endif
            break;
        case 0x3b4:
        case 0x3d4:
            val = s->cr_index;
            break;
        case 0x3b5:
        case 0x3d5:
            val = s->cr[s->cr_index];
#ifdef DEBUG_VGA_REG
            printf("vga: read CR%x = 0x%02x\n", s->cr_index, val);
#endif
            break;
        case 0x3ba:
        case 0x3da:
            /* just toggle to fool polling */
            s->st01 ^= ST01_V_RETRACE | ST01_DISP_ENABLE;
            val = s->st01;
            s->ar_flip_flop = 0;
            break;
        default:
            val = 0x00;
            break;
        }
    }
#if defined(DEBUG_VGA)
    printf("VGA: read addr=0x%04x data=0x%02x\n", addr, val);
#endif
    return val;
}

static void vga_ioport_write(void *opaque, uint32_t addr, uint32_t val)
{
    VGAState *s = opaque;
    int index;

    /* check port range access depending on color/monochrome mode */
    if ((addr >= 0x3b0 && addr <= 0x3bf && (s->msr & MSR_COLOR_EMULATION)) ||
        (addr >= 0x3d0 && addr <= 0x3df && !(s->msr & MSR_COLOR_EMULATION)))
        return;

#ifdef DEBUG_VGA
    printf("VGA: write addr=0x%04x data=0x%02x\n", addr, val);
#endif

    switch(addr) {
    case 0x3c0:
        if (s->ar_flip_flop == 0) {
            val &= 0x3f;
            s->ar_index = val;
        } else {
            index = s->ar_index & 0x1f;
            switch(index) {
            case 0x00 ... 0x0f:
                s->ar[index] = val & 0x3f;
                break;
            case 0x10:
                s->ar[index] = val & ~0x10;
                break;
            case 0x11:
                s->ar[index] = val;
                break;
            case 0x12:
                s->ar[index] = val & ~0xc0;
                break;
            case 0x13:
                s->ar[index] = val & ~0xf0;
                break;
            case 0x14:
                s->ar[index] = val & ~0xf0;
                break;
            default:
                break;
            }
        }
        s->ar_flip_flop ^= 1;
        break;
    case 0x3c2:
        s->msr = val & ~0x10;
        break;
    case 0x3c4:
        s->sr_index = val & 7;
        break;
    case 0x3c5:
#ifdef DEBUG_VGA_REG
        printf("vga: write SR%x = 0x%02x\n", s->sr_index, val);
#endif
        s->sr[s->sr_index] = val & sr_mask[s->sr_index];
        break;
    case 0x3c7:
        s->dac_read_index = val;
        s->dac_sub_index = 0;
        s->dac_state = 3;
        break;
    case 0x3c8:
        s->dac_write_index = val;
        s->dac_sub_index = 0;
        s->dac_state = 0;
        break;
    case 0x3c9:
        s->dac_cache[s->dac_sub_index] = val;
        if (++s->dac_sub_index == 3) {
            memcpy(&s->palette[s->dac_write_index * 3], s->dac_cache, 3);
            s->dac_sub_index = 0;
            s->dac_write_index++;
        }
        break;
    case 0x3ce:
        s->gr_index = val & 0x0f;
        break;
    case 0x3cf:
#ifdef DEBUG_VGA_REG
        printf("vga: write GR%x = 0x%02x\n", s->gr_index, val);
#endif
        s->gr[s->gr_index] = val & gr_mask[s->gr_index];
        break;
    case 0x3b4:
    case 0x3d4:
        s->cr_index = val;
        break;
    case 0x3b5:
    case 0x3d5:
#ifdef DEBUG_VGA_REG
        printf("vga: write CR%x = 0x%02x\n", s->cr_index, val);
#endif
        /* handle CR0-7 protection */
        if ((s->cr[0x11] & 0x80) && s->cr_index <= 7) {
            /* can always write bit 4 of CR7 */
            if (s->cr_index == 7)
                s->cr[7] = (s->cr[7] & ~0x10) | (val & 0x10);
            return;
        }
        switch(s->cr_index) {
        case 0x01: /* horizontal display end */
        case 0x07:
        case 0x09:
        case 0x0c:
        case 0x0d:
        case 0x12: /* veritcal display end */
            s->cr[s->cr_index] = val;
            break;
        default:
            s->cr[s->cr_index] = val;
            break;
        }
        break;
    case 0x3ba:
    case 0x3da:
        s->fcr = val & 0x10;
        break;
    }
}

#ifdef CONFIG_BOCHS_VBE
static uint32_t vbe_ioport_read_index(void *opaque, uint32_t addr)
{
    VGAState *s = opaque;
    uint32_t val;
    val = s->vbe_index;
    return val;
}

static uint32_t vbe_ioport_read_data(void *opaque, uint32_t addr)
{
    VGAState *s = opaque;
    uint32_t val;

    if (s->vbe_index <= VBE_DISPI_INDEX_NB)
        val = s->vbe_regs[s->vbe_index];
    else
        val = 0;
#ifdef DEBUG_BOCHS_VBE
    printf("VBE: read index=0x%x val=0x%x\n", s->vbe_index, val);
#endif
    return val;
}

static void vbe_ioport_write_index(void *opaque, uint32_t addr, uint32_t val)
{
    VGAState *s = opaque;
    s->vbe_index = val;
}

static void vbe_ioport_write_data(void *opaque, uint32_t addr, uint32_t val)
{
    VGAState *s = opaque;

    if (s->vbe_index <= VBE_DISPI_INDEX_NB) {
#ifdef DEBUG_BOCHS_VBE
        printf("VBE: write index=0x%x val=0x%x\n", s->vbe_index, val);
#endif
        switch(s->vbe_index) {
        case VBE_DISPI_INDEX_ID:
            if (val == VBE_DISPI_ID0 ||
                val == VBE_DISPI_ID1 ||
                val == VBE_DISPI_ID2) {
                s->vbe_regs[s->vbe_index] = val;
            }
            break;
        case VBE_DISPI_INDEX_XRES:
            if ((val <= VBE_DISPI_MAX_XRES) && ((val & 7) == 0)) {
                s->vbe_regs[s->vbe_index] = val;
            }
            break;
        case VBE_DISPI_INDEX_YRES:
            if (val <= VBE_DISPI_MAX_YRES) {
                s->vbe_regs[s->vbe_index] = val;
            }
            break;
        case VBE_DISPI_INDEX_BPP:
            if (val == 0)
                val = 8;
            if (val == 4 || val == 8 || val == 15 || 
                val == 16 || val == 24 || val == 32) {
                s->vbe_regs[s->vbe_index] = val;
            }
            break;
        case VBE_DISPI_INDEX_BANK:
            val &= s->vbe_bank_mask;
            s->vbe_regs[s->vbe_index] = val;
            s->bank_offset = (val << 16);
            break;
        case VBE_DISPI_INDEX_ENABLE:
            if (val & VBE_DISPI_ENABLED) {
                int h, shift_control;

                s->vbe_regs[VBE_DISPI_INDEX_VIRT_WIDTH] = 
                    s->vbe_regs[VBE_DISPI_INDEX_XRES];
                s->vbe_regs[VBE_DISPI_INDEX_VIRT_HEIGHT] = 
                    s->vbe_regs[VBE_DISPI_INDEX_YRES];
                s->vbe_regs[VBE_DISPI_INDEX_X_OFFSET] = 0;
                s->vbe_regs[VBE_DISPI_INDEX_Y_OFFSET] = 0;
                
                if (s->vbe_regs[VBE_DISPI_INDEX_BPP] == 4)
                    s->vbe_line_offset = s->vbe_regs[VBE_DISPI_INDEX_XRES] >> 1;
                else
                    s->vbe_line_offset = s->vbe_regs[VBE_DISPI_INDEX_XRES] * 
                        ((s->vbe_regs[VBE_DISPI_INDEX_BPP] + 7) >> 3);
                s->vbe_start_addr = 0;
                
                /* clear the screen (should be done in BIOS) */
                if (!(val & VBE_DISPI_NOCLEARMEM)) {
                    memset(s->vram_ptr, 0, 
                           s->vbe_regs[VBE_DISPI_INDEX_YRES] * s->vbe_line_offset);
                }
                
                /* we initialize the VGA graphic mode (should be done
                   in BIOS) */
                s->gr[0x06] = (s->gr[0x06] & ~0x0c) | 0x05; /* graphic mode + memory map 1 */
                s->cr[0x17] |= 3; /* no CGA modes */
                s->cr[0x13] = s->vbe_line_offset >> 3;
                /* width */
                s->cr[0x01] = (s->vbe_regs[VBE_DISPI_INDEX_XRES] >> 3) - 1;
                /* height */
                h = s->vbe_regs[VBE_DISPI_INDEX_YRES] - 1;
                s->cr[0x12] = h;
                s->cr[0x07] = (s->cr[0x07] & ~0x42) | 
                    ((h >> 7) & 0x02) | ((h >> 3) & 0x40);
                /* line compare to 1023 */