hw/framebuffer.c

   1 /*
   2  * Framebuffer device helper routines
   3  *
   4  * Copyright (c) 2009 CodeSourcery
   5  * Written by Paul Brook <paul@codesourcery.com>
   6  *
   7  * This code is licensed under the GNU GPLv2.
   8  *
   9  * Contributions after 2012-01-13 are licensed under the terms of the
  10  * GNU GPL, version 2 or (at your option) any later version.
  11  */
  12
  13 /* TODO:
  14    - Do something similar for framebuffers with local ram
  15    - Handle rotation here instead of hacking dest_pitch
  16    - Use common pixel conversion routines instead of per-device drawfn
  17    - Remove all DisplayState knowledge from devices.
  18  */
  19
  20 #include "hw.h"
  21 #include "console.h"
  22 #include "framebuffer.h"
  23
  24 /* Render an image from a shared memory framebuffer.  */
  25
  26 void framebuffer_update_display(
  27     DisplayState *ds,
  28     MemoryRegion *address_space,
  29     hwaddr base,
  30     int cols, /* Width in pixels.  */
  31     int rows, /* Height in pixels.  */
  32     int src_width, /* Length of source line, in bytes.  */
  33     int dest_row_pitch, /* Bytes between adjacent horizontal output pixels.  */
  34     int dest_col_pitch, /* Bytes between adjacent vertical output pixels.  */
  35     int invalidate, /* nonzero to redraw the whole image.  */
  36     drawfn fn,
  37     void *opaque,
  38     int *first_row, /* Input and output.  */
  39     int *last_row /* Output only */)
  40 {
  41     hwaddr src_len;
  42     uint8_t *dest;
  43     uint8_t *src;
  44     uint8_t *src_base;
  45     int first, last = 0;
  46     int dirty;
  47     int i;
  48     ram_addr_t addr;
  49     MemoryRegionSection mem_section;
  50     MemoryRegion *mem;
  51
  52     i = *first_row;
  53     *first_row = -1;
  54     src_len = src_width * rows;
  55
  56     mem_section = memory_region_find(address_space, base, src_len);
  57     if (mem_section.size != src_len || !memory_region_is_ram(mem_section.mr)) {
  58         return;
  59     }
  60     mem = mem_section.mr;
  61     assert(mem);
  62     assert(mem_section.offset_within_address_space == base);
  63
  64     memory_region_sync_dirty_bitmap(mem);
  65     src_base = cpu_physical_memory_map(base, &src_len, 0);
  66     /* If we can't map the framebuffer then bail.  We could try harder,
  67        but it's not really worth it as dirty flag tracking will probably
  68        already have failed above.  */
  69     if (!src_base)
  70         return;
  71     if (src_len != src_width * rows) {
  72         cpu_physical_memory_unmap(src_base, src_len, 0, 0);
  73         return;
  74     }
  75     src = src_base;
  76     dest = ds_get_data(ds);
  77     if (dest_col_pitch < 0)
  78         dest -= dest_col_pitch * (cols - 1);
  79     if (dest_row_pitch < 0) {
  80         dest -= dest_row_pitch * (rows - 1);
  81     }
  82     first = -1;
  83     addr = mem_section.offset_within_region;
  84
  85     addr += i * src_width;
  86     src += i * src_width;
  87     dest += i * dest_row_pitch;
  88
  89     for (; i < rows; i++) {
  90         dirty = memory_region_get_dirty(mem, addr, src_width,
  91                                              DIRTY_MEMORY_VGA);
  92         if (dirty || invalidate) {
  93             fn(opaque, dest, src, cols, dest_col_pitch);
  94             if (first == -1)
  95                 first = i;
  96             last = i;
  97         }
  98         addr += src_width;
  99         src += src_width;
 100         dest += dest_row_pitch;
 101     }
 102     cpu_physical_memory_unmap(src_base, src_len, 0, 0);
 103     if (first < 0) {
 104         return;
 105     }
 106     memory_region_reset_dirty(mem, mem_section.offset_within_region, src_len,
 107                               DIRTY_MEMORY_VGA);
 108     *first_row = first;
 109     *last_row = last;
 110 }