vga.c

qemu虚拟机代码

        s->line_compare = line_compare;
        full_update = 1;
    }
    return full_update;
}

static inline int get_depth_index(int depth)
{
    switch(depth) {
    default:
    case 8:
        return 0;
    case 15:
        return 1;
    case 16:
        return 2;
    case 32:
        return 3;
    }
}

static vga_draw_glyph8_func *vga_draw_glyph8_table[4] = {
    vga_draw_glyph8_8,
    vga_draw_glyph8_16,
    vga_draw_glyph8_16,
    vga_draw_glyph8_32,
};

static vga_draw_glyph8_func *vga_draw_glyph16_table[4] = {
    vga_draw_glyph16_8,
    vga_draw_glyph16_16,
    vga_draw_glyph16_16,
    vga_draw_glyph16_32,
};

static vga_draw_glyph9_func *vga_draw_glyph9_table[4] = {
    vga_draw_glyph9_8,
    vga_draw_glyph9_16,
    vga_draw_glyph9_16,
    vga_draw_glyph9_32,
};
    
static const uint8_t cursor_glyph[32 * 4] = {
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
};    

/* 
 * Text mode update 
 * Missing:
 * - double scan
 * - double width 
 * - underline
 * - flashing
 */
static void vga_draw_text(VGAState *s, int full_update)
{
    int cx, cy, cheight, cw, ch, cattr, height, width, ch_attr;
    int cx_min, cx_max, linesize, x_incr;
    uint32_t offset, fgcol, bgcol, v, cursor_offset;
    uint8_t *d1, *d, *src, *s1, *dest, *cursor_ptr;
    const uint8_t *font_ptr, *font_base[2];
    int dup9, line_offset, depth_index;
    uint32_t *palette;
    uint32_t *ch_attr_ptr;
    vga_draw_glyph8_func *vga_draw_glyph8;
    vga_draw_glyph9_func *vga_draw_glyph9;

    full_update |= update_palette16(s);
    palette = s->last_palette;
    
    /* compute font data address (in plane 2) */
    v = s->sr[3];
    offset = (((v >> 4) & 1) | ((v << 1) & 6)) * 8192 * 4 + 2;
    if (offset != s->font_offsets[0]) {
        s->font_offsets[0] = offset;
        full_update = 1;
    }
    font_base[0] = s->vram_ptr + offset;

    offset = (((v >> 5) & 1) | ((v >> 1) & 6)) * 8192 * 4 + 2;
    font_base[1] = s->vram_ptr + offset;
    if (offset != s->font_offsets[1]) {
        s->font_offsets[1] = offset;
        full_update = 1;
    }
    if (s->plane_updated & (1 << 2)) {
        /* if the plane 2 was modified since the last display, it
           indicates the font may have been modified */
        s->plane_updated = 0;
        full_update = 1;
    }
    full_update |= update_basic_params(s);

    line_offset = s->line_offset;
    s1 = s->vram_ptr + (s->start_addr * 4);

    /* total width & height */
    cheight = (s->cr[9] & 0x1f) + 1;
    cw = 8;
    if (!(s->sr[1] & 0x01))
        cw = 9;
    if (s->sr[1] & 0x08)
        cw = 16; /* NOTE: no 18 pixel wide */
    x_incr = cw * ((s->ds->depth + 7) >> 3);
    width = (s->cr[0x01] + 1);
    if (s->cr[0x06] == 100) {
        /* ugly hack for CGA 160x100x16 - explain me the logic */
        height = 100;
    } else {
        height = s->cr[0x12] | 
            ((s->cr[0x07] & 0x02) << 7) | 
            ((s->cr[0x07] & 0x40) << 3);
        height = (height + 1) / cheight;
    }
    if ((height * width) > CH_ATTR_SIZE) {
        /* better than nothing: exit if transient size is too big */
        return;
    }

    if (width != s->last_width || height != s->last_height ||
        cw != s->last_cw || cheight != s->last_ch) {
        s->last_scr_width = width * cw;
        s->last_scr_height = height * cheight;
        dpy_resize(s->ds, s->last_scr_width, s->last_scr_height);
        s->last_width = width;
        s->last_height = height;
        s->last_ch = cheight;
        s->last_cw = cw;
        full_update = 1;
    }
    cursor_offset = ((s->cr[0x0e] << 8) | s->cr[0x0f]) - s->start_addr;
    if (cursor_offset != s->cursor_offset ||
        s->cr[0xa] != s->cursor_start ||
        s->cr[0xb] != s->cursor_end) {
      /* if the cursor position changed, we update the old and new
         chars */
        if (s->cursor_offset < CH_ATTR_SIZE)
            s->last_ch_attr[s->cursor_offset] = -1;
        if (cursor_offset < CH_ATTR_SIZE)
            s->last_ch_attr[cursor_offset] = -1;
        s->cursor_offset = cursor_offset;
        s->cursor_start = s->cr[0xa];
        s->cursor_end = s->cr[0xb];
    }
    cursor_ptr = s->vram_ptr + (s->start_addr + cursor_offset) * 4;
    
    depth_index = get_depth_index(s->ds->depth);
    if (cw == 16)
        vga_draw_glyph8 = vga_draw_glyph16_table[depth_index];
    else
        vga_draw_glyph8 = vga_draw_glyph8_table[depth_index];
    vga_draw_glyph9 = vga_draw_glyph9_table[depth_index];
    
    dest = s->ds->data;
    linesize = s->ds->linesize;
    ch_attr_ptr = s->last_ch_attr;
    for(cy = 0; cy < height; cy++) {
        d1 = dest;
        src = s1;
        cx_min = width;
        cx_max = -1;
        for(cx = 0; cx < width; cx++) {
            ch_attr = *(uint16_t *)src;
            if (full_update || ch_attr != *ch_attr_ptr) {
                if (cx < cx_min)
                    cx_min = cx;
                if (cx > cx_max)
                    cx_max = cx;
                *ch_attr_ptr = ch_attr;
#ifdef WORDS_BIGENDIAN
                ch = ch_attr >> 8;
                cattr = ch_attr & 0xff;
#else
                ch = ch_attr & 0xff;
                cattr = ch_attr >> 8;
#endif
                font_ptr = font_base[(cattr >> 3) & 1];
                font_ptr += 32 * 4 * ch;
                bgcol = palette[cattr >> 4];
                fgcol = palette[cattr & 0x0f];
                if (cw != 9) {
                    vga_draw_glyph8(d1, linesize, 
                                    font_ptr, cheight, fgcol, bgcol);
                } else {
                    dup9 = 0;
                    if (ch >= 0xb0 && ch <= 0xdf && (s->ar[0x10] & 0x04))
                        dup9 = 1;
                    vga_draw_glyph9(d1, linesize, 
                                    font_ptr, cheight, fgcol, bgcol, dup9);
                }
                if (src == cursor_ptr &&
                    !(s->cr[0x0a] & 0x20)) {
                    int line_start, line_last, h;
                    /* draw the cursor */
                    line_start = s->cr[0x0a] & 0x1f;
                    line_last = s->cr[0x0b] & 0x1f;
                    /* XXX: check that */
                    if (line_last > cheight - 1)
                        line_last = cheight - 1;
                    if (line_last >= line_start && line_start < cheight) {
                        h = line_last - line_start + 1;
                        d = d1 + linesize * line_start;
                        if (cw != 9) {
                            vga_draw_glyph8(d, linesize, 
                                            cursor_glyph, h, fgcol, bgcol);
                        } else {
                            vga_draw_glyph9(d, linesize, 
                                            cursor_glyph, h, fgcol, bgcol, 1);
                        }
                    }
                }
            }
            d1 += x_incr;
            src += 4;
            ch_attr_ptr++;
        }
        if (cx_max != -1) {
            dpy_update(s->ds, cx_min * cw, cy * cheight, 
                       (cx_max - cx_min + 1) * cw, cheight);
        }
        dest += linesize * cheight;
        s1 += line_offset;
    }
}

enum {
    VGA_DRAW_LINE2,
    VGA_DRAW_LINE2D2,
    VGA_DRAW_LINE4,
    VGA_DRAW_LINE4D2,
    VGA_DRAW_LINE8D2,
    VGA_DRAW_LINE8,
    VGA_DRAW_LINE15,
    VGA_DRAW_LINE16,
    VGA_DRAW_LINE24,
    VGA_DRAW_LINE32,
    VGA_DRAW_LINE_NB,
};

static vga_draw_line_func *vga_draw_line_table[4 * VGA_DRAW_LINE_NB] = {
    vga_draw_line2_8,
    vga_draw_line2_16,
    vga_draw_line2_16,
    vga_draw_line2_32,

    vga_draw_line2d2_8,
    vga_draw_line2d2_16,
    vga_draw_line2d2_16,
    vga_draw_line2d2_32,

    vga_draw_line4_8,
    vga_draw_line4_16,
    vga_draw_line4_16,
    vga_draw_line4_32,

    vga_draw_line4d2_8,
    vga_draw_line4d2_16,
    vga_draw_line4d2_16,
    vga_draw_line4d2_32,

    vga_draw_line8d2_8,
    vga_draw_line8d2_16,
    vga_draw_line8d2_16,
    vga_draw_line8d2_32,

    vga_draw_line8_8,
    vga_draw_line8_16,
    vga_draw_line8_16,
    vga_draw_line8_32,

    vga_draw_line15_8,
    vga_draw_line15_15,
    vga_draw_line15_16,
    vga_draw_line15_32,

    vga_draw_line16_8,
    vga_draw_line16_15,
    vga_draw_line16_16,
    vga_draw_line16_32,

    vga_draw_line24_8,
    vga_draw_line24_15,
    vga_draw_line24_16,
    vga_draw_line24_32,

    vga_draw_line32_8,
    vga_draw_line32_15,
    vga_draw_line32_16,
    vga_draw_line32_32,
};

static int vga_get_bpp(VGAState *s)
{
    int ret;
#ifdef CONFIG_BOCHS_VBE
    if (s->vbe_regs[VBE_DISPI_INDEX_ENABLE] & VBE_DISPI_ENABLED) {
        ret = s->vbe_regs[VBE_DISPI_INDEX_BPP];
    } else 
#endif
    {
        ret = 0;
    }
    return ret;
}

static void vga_get_resolution(VGAState *s, int *pwidth, int *pheight)
{
    int width, height;
    
    width = (s->cr[0x01] + 1) * 8;
    height = s->cr[0x12] | 
        ((s->cr[0x07] & 0x02) << 7) | 
        ((s->cr[0x07] & 0x40) << 3);
    height = (height + 1);
    *pwidth = width;
    *pheight = height;
}

void vga_invalidate_scanlines(VGAState *s, int y1, int y2)
{
    int y;
    if (y1 >= VGA_MAX_HEIGHT)
        return;
    if (y2 >= VGA_MAX_HEIGHT)
        y2 = VGA_MAX_HEIGHT;
    for(y = y1; y < y2; y++) {
        s->invalidated_y_table[y >> 5] |= 1 << (y & 0x1f);
    }
}

/* 
 * graphic modes
 */
static void vga_draw_graphic(VGAState *s, int full_update)
{
    int y1, y, update, page_min, page_max, linesize, y_start, double_scan, mask;
    int width, height, shift_control, line_offset, page0, page1, bwidth;
    int disp_width, multi_scan, multi_run;
    uint8_t *d;
    uint32_t v, addr1, addr;
    vga_draw_line_func *vga_draw_line;
    
    full_update |= update_basic_params(s);

    s->get_resolution(s, &width, &height);
    disp_width = width;

    shift_control = (s->gr[0x05] >> 5) & 3;
    double_scan = (s->cr[0x09] >> 7);
    if (shift_control != 1) {
        multi_scan = (((s->cr[0x09] & 0x1f) + 1) << double_scan) - 1;
    } else {
        /* in CGA modes, multi_scan is ignored */
        /* XXX: is it correct ? */
        multi_scan = double_scan;
    }
    multi_run = multi_scan;
    if (shift_control != s->shift_control ||
        double_scan != s->double_scan) {
        full_update = 1;
        s->shift_control = shift_control;
        s->double_scan = double_scan;
    }
    
    if (shift_control == 0) {
        full_update |= update_palette16(s);
        if (s->sr[0x01] & 8) {
            v = VGA_DRAW_LINE4D2;
            disp_width <<= 1;
        } else {
            v = VGA_DRAW_LINE4;
        }
    } else if (shift_control == 1) {
        full_update |= update_palette16(s);
        if (s->sr[0x01] & 8) {
            v = VGA_DRAW_LINE2D2;
            disp_width <<= 1;
        } else {
            v = VGA_DRAW_LINE2;
        }
    } else {
        switch(s->get_bpp(s)) {
        default:
        case 0:
            full_update |= update_palette256(s);
            v = VGA_DRAW_LINE8D2;
            break;
        case 8:
            full_update |= update_palette256(s);
            v = VGA_DRAW_LINE8;
            break;
        case 15:
            v = VGA_DRAW_LINE15;
            break;
        case 16:
            v = VGA_DRAW_LINE16;
            break;
        case 24:
            v = VGA_DRAW_LINE24;
            break;
        case 32:
            v = VGA_DRAW_LINE32;
            break;
        }
    }
    vga_draw_line = vga_draw_line_table[v * 4 + get_depth_index(s->ds->depth)];

    if (disp_width != s->last_width ||
        height != s->last_height) {
        dpy_resize(s->ds, disp_width, height);
        s->last_scr_width = disp_width;
        s->last_scr_height = height;
        s->last_width = disp_width;
        s->last_height = height;
        full_update = 1;
    }
    if (s->cursor_invalidate)
        s->cursor_invalidate(s);
    
    line_offset = s->line_offset;
#if 0
    printf("w=%d h=%d v=%d line_offset=%d cr[0x09]=0x%02x cr[0x17]=0x%02x linecmp=%d sr[0x01]=0x%02x\n",
           width, height, v, line_offset, s->cr[9], s->cr[0x17], s->line_compare, s->sr[0x01]);
#endif
    addr1 = (s->start_addr * 4);
    bwidth = width * 4;
    y_start = -1;
    page_min = 0x7fffffff;
    page_max = -1;
    d = s->ds->data;
    linesize = s->ds->linesize;
    y1 = 0;
    for(y = 0; y < height; y++) {
        addr = addr1;
        if (!(s->cr[0x17] & 1)) {
            int shift;
            /* CGA compatibility handling */
            shift = 14 + ((s->cr[0x17] >> 6) & 1);
            addr = (addr & ~(1 << shift)) | ((y1 & 1) << shift);
        }
        if (!(s->cr[0x17] & 2)) {
            addr = (addr & ~0x8000) | ((y1 & 2) << 14);
        }
        page0 = s->vram_offset + (addr & TARGET_PAGE_MASK);
        page1 = s->vram_offset + ((addr + bwidth - 1) & TARGET_PAGE_MASK);
        update = full_update | 
            cpu_physical_memory_get_dirty(page0, VGA_DIRTY_FLAG) |
            cpu_physical_memory_get_dirty(page1, VGA_DIRTY_FLAG);
        if ((page1 - page0) > TARGET_PAGE_SIZE) {
            /* if wide line, can use another page */
            update |= cpu_physical_memory_get_dirty(page0 + TARGET_PAGE_SIZE, 
                                                    VGA_DIRTY_FLAG);
        }
        /* explicit invalidation for the hardware cursor */
        update |= (s->invalidated_y_table[y >> 5] >> (y & 0x1f)) & 1;
        if (update) {
            if (y_start < 0)