xref: /openbmc/qemu/hw/display/ramfb.c (revision dfd3bb0a99ae9627b4cc9b310ecef1b214188f71)
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  
22  struct 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  
31  typedef struct RAMFBCfg RAMFBCfg;
32  
33  struct RAMFBState {
34      DisplaySurface *ds;
35      uint32_t width, height;
36      struct RAMFBCfg cfg;
37  };
38  
39  static void ramfb_unmap_display_surface(pixman_image_t *image, void *unused)
40  {
41      void *data = pixman_image_get_data(image);
42      uint32_t size = pixman_image_get_stride(image) *
43          pixman_image_get_height(image);
44      cpu_physical_memory_unmap(data, size, 0, 0);
45  }
46  
47  static DisplaySurface *ramfb_create_display_surface(int width, int height,
48                                                      pixman_format_code_t format,
49                                                      hwaddr stride, hwaddr addr)
50  {
51      DisplaySurface *surface;
52      hwaddr size, mapsize, linesize;
53      void *data;
54  
55      if (width < 16 || width > VBE_DISPI_MAX_XRES ||
56          height < 16 || height > VBE_DISPI_MAX_YRES ||
57          format == 0 /* unknown format */)
58          return NULL;
59  
60      linesize = width * PIXMAN_FORMAT_BPP(format) / 8;
61      if (stride == 0) {
62          stride = linesize;
63      }
64  
65      mapsize = size = stride * (height - 1) + linesize;
66      data = cpu_physical_memory_map(addr, &mapsize, false);
67      if (size != mapsize) {
68          cpu_physical_memory_unmap(data, mapsize, 0, 0);
69          return NULL;
70      }
71  
72      surface = qemu_create_displaysurface_from(width, height,
73                                                format, stride, data);
74      pixman_image_set_destroy_function(surface->image,
75                                        ramfb_unmap_display_surface, NULL);
76  
77      return surface;
78  }
79  
80  static void ramfb_fw_cfg_write(void *dev, off_t offset, size_t len)
81  {
82      RAMFBState *s = dev;
83      DisplaySurface *surface;
84      uint32_t fourcc, format, width, height;
85      hwaddr stride, addr;
86  
87      width  = be32_to_cpu(s->cfg.width);
88      height = be32_to_cpu(s->cfg.height);
89      stride = be32_to_cpu(s->cfg.stride);
90      fourcc = be32_to_cpu(s->cfg.fourcc);
91      addr   = be64_to_cpu(s->cfg.addr);
92      format = qemu_drm_format_to_pixman(fourcc);
93  
94      surface = ramfb_create_display_surface(width, height,
95                                             format, stride, addr);
96      if (!surface) {
97          return;
98      }
99  
100      s->width = width;
101      s->height = height;
102      qemu_free_displaysurface(s->ds);
103      s->ds = surface;
104  }
105  
106  void ramfb_display_update(QemuConsole *con, RAMFBState *s)
107  {
108      if (!s->width || !s->height) {
109          return;
110      }
111  
112      if (s->ds) {
113          dpy_gfx_replace_surface(con, s->ds);
114          s->ds = NULL;
115      }
116  
117      /* simple full screen update */
118      dpy_gfx_update_full(con);
119  }
120  
121  static int ramfb_post_load(void *opaque, int version_id)
122  {
123      ramfb_fw_cfg_write(opaque, 0, 0);
124      return 0;
125  }
126  
127  const VMStateDescription ramfb_vmstate = {
128      .name = "ramfb",
129      .version_id = 1,
130      .minimum_version_id = 1,
131      .post_load = ramfb_post_load,
132      .fields = (VMStateField[]) {
133          VMSTATE_BUFFER_UNSAFE(cfg, RAMFBState, 0, sizeof(RAMFBCfg)),
134          VMSTATE_END_OF_LIST()
135      }
136  };
137  
138  RAMFBState *ramfb_setup(Error **errp)
139  {
140      FWCfgState *fw_cfg = fw_cfg_find();
141      RAMFBState *s;
142  
143      if (!fw_cfg || !fw_cfg->dma_enabled) {
144          error_setg(errp, "ramfb device requires fw_cfg with DMA");
145          return NULL;
146      }
147  
148      s = g_new0(RAMFBState, 1);
149  
150      rom_add_vga("vgabios-ramfb.bin");
151      fw_cfg_add_file_callback(fw_cfg, "etc/ramfb",
152                               NULL, ramfb_fw_cfg_write, s,
153                               &s->cfg, sizeof(s->cfg), false);
154      return s;
155  }
156