void framebuffer_update_display(

    DisplaySurface *ds,

    MemoryRegionSection *mem_section,

    int cols, /* Width in pixels.  */

    int rows, /* Height in pixels.  */

    int src_width, /* Length of source line, in bytes.  */

    int dest_row_pitch, /* Bytes between adjacent horizontal output pixels.  */

    int dest_col_pitch, /* Bytes between adjacent vertical output pixels.  */

    int invalidate, /* nonzero to redraw the whole image.  */

    drawfn fn,

    void *opaque,

    int *first_row, /* Input and output.  */

    int *last_row /* Output only */)

{

    hwaddr src_len;

    uint8_t *dest;

    uint8_t *src;

    int first, last = 0;

    int dirty;

    int i;

    ram_addr_t addr;

    MemoryRegion *mem;



    i = *first_row;

    *first_row = -1;

    src_len = src_width * rows;



    mem = mem_section->mr;

    if (!mem) {

        return;

    }

    memory_region_sync_dirty_bitmap(mem);



    addr = mem_section->offset_within_region;

    src = memory_region_get_ram_ptr(mem) + addr;



    dest = surface_data(ds);

    if (dest_col_pitch < 0) {

        dest -= dest_col_pitch * (cols - 1);

    }

    if (dest_row_pitch < 0) {

        dest -= dest_row_pitch * (rows - 1);

    }

    first = -1;



    addr += i * src_width;

    src += i * src_width;

    dest += i * dest_row_pitch;



    for (; i < rows; i++) {

        dirty = memory_region_get_dirty(mem, addr, src_width,

                                             DIRTY_MEMORY_VGA);

        if (dirty || invalidate) {

            fn(opaque, dest, src, cols, dest_col_pitch);

            if (first == -1)

                first = i;

            last = i;

        }

        addr += src_width;

        src += src_width;

        dest += dest_row_pitch;

    }

    if (first < 0) {

        return;

    }

    memory_region_reset_dirty(mem, mem_section->offset_within_region, src_len,

                              DIRTY_MEMORY_VGA);

    *first_row = first;

    *last_row = last;

}
