LXR qemu/hw/display/ramfb.c

   1/*
   2 * early boot framebuffer in guest ram
   3 * configured using fw_cfg
   4 *
   5 * Copyright Red Hat, Inc. 2017
   6 *
   7 * Author:
   8 *     Gerd Hoffmann <kraxel@redhat.com>
   9 *
  10 * This work is licensed under the terms of the GNU GPL, version 2 or later.
  11 * See the COPYING file in the top-level directory.
  12 */
  13
  14#include "qemu/osdep.h"
  15#include "qapi/error.h"
  16#include "hw/loader.h"
  17#include "hw/display/ramfb.h"
  18#include "hw/display/bochs-vbe.h" /* for limits */
  19#include "ui/console.h"
  20#include "sysemu/reset.h"
  21
  22struct QEMU_PACKED RAMFBCfg {
  23    uint64_t addr;
  24    uint32_t fourcc;
  25    uint32_t flags;
  26    uint32_t width;
  27    uint32_t height;
  28    uint32_t stride;
  29};
  30
  31struct RAMFBState {
  32    DisplaySurface *ds;
  33    uint32_t width, height;
  34    struct RAMFBCfg cfg;
  35};
  36
  37static void ramfb_unmap_display_surface(pixman_image_t *image, void *unused)
  38{
  39    void *data = pixman_image_get_data(image);
  40    uint32_t size = pixman_image_get_stride(image) *
  41        pixman_image_get_height(image);
  42    cpu_physical_memory_unmap(data, size, 0, 0);
  43}
  44
  45static DisplaySurface *ramfb_create_display_surface(int width, int height,
  46                                                    pixman_format_code_t format,
  47                                                    hwaddr stride, hwaddr addr)
  48{
  49    DisplaySurface *surface;
  50    hwaddr size, mapsize, linesize;
  51    void *data;
  52
  53    if (width < 16 || width > VBE_DISPI_MAX_XRES ||
  54        height < 16 || height > VBE_DISPI_MAX_YRES ||
  55        format == 0 /* unknown format */)
  56        return NULL;
  57
  58    linesize = width * PIXMAN_FORMAT_BPP(format) / 8;
  59    if (stride == 0) {
  60        stride = linesize;
  61    }
  62
  63    mapsize = size = stride * (height - 1) + linesize;
  64    data = cpu_physical_memory_map(addr, &mapsize, false);
  65    if (size != mapsize) {
  66        cpu_physical_memory_unmap(data, mapsize, 0, 0);
  67        return NULL;
  68    }
  69
  70    surface = qemu_create_displaysurface_from(width, height,
  71                                              format, stride, data);
  72    pixman_image_set_destroy_function(surface->image,
  73                                      ramfb_unmap_display_surface, NULL);
  74
  75    return surface;
  76}
  77
  78static void ramfb_fw_cfg_write(void *dev, off_t offset, size_t len)
  79{
  80    RAMFBState *s = dev;
  81    DisplaySurface *surface;
  82    uint32_t fourcc, format, width, height;
  83    hwaddr stride, addr;
  84
  85    width  = be32_to_cpu(s->cfg.width);
  86    height = be32_to_cpu(s->cfg.height);
  87    stride = be32_to_cpu(s->cfg.stride);
  88    fourcc = be32_to_cpu(s->cfg.fourcc);
  89    addr   = be64_to_cpu(s->cfg.addr);
  90    format = qemu_drm_format_to_pixman(fourcc);
  91
  92    surface = ramfb_create_display_surface(width, height,
  93                                           format, stride, addr);
  94    if (!surface) {
  95        return;
  96    }
  97
  98    s->width = width;
  99    s->height = height;
 100    s->ds = surface;
 101}
 102
 103void ramfb_display_update(QemuConsole *con, RAMFBState *s)
 104{
 105    if (!s->width || !s->height) {
 106        return;
 107    }
 108
 109    if (s->ds) {
 110        dpy_gfx_replace_surface(con, s->ds);
 111        s->ds = NULL;
 112    }
 113
 114    /* simple full screen update */
 115    dpy_gfx_update_full(con);
 116}
 117
 118RAMFBState *ramfb_setup(Error **errp)
 119{
 120    FWCfgState *fw_cfg = fw_cfg_find();
 121    RAMFBState *s;
 122
 123    if (!fw_cfg || !fw_cfg->dma_enabled) {
 124        error_setg(errp, "ramfb device requires fw_cfg with DMA");
 125        return NULL;
 126    }
 127
 128    s = g_new0(RAMFBState, 1);
 129
 130    rom_add_vga("vgabios-ramfb.bin");
 131    fw_cfg_add_file_callback(fw_cfg, "etc/ramfb",
 132                             NULL, ramfb_fw_cfg_write, s,
 133                             &s->cfg, sizeof(s->cfg), false);
 134    return s;
 135}
 136