xref: /qemu/hw/display/ramfb.c (revision 834e8bf17c067bbc00e4034b10cec98eef363431)
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 "qemu/option.h"
17  #include "hw/loader.h"
18  #include "hw/display/ramfb.h"
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  struct RAMFBState {
32      DisplaySurface *ds;
33      uint32_t width, height;
34      uint32_t starting_width, starting_height;
35      struct RAMFBCfg cfg;
36      bool locked;
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                                                      int linesize, uint64_t addr)
50  {
51      DisplaySurface *surface;
52      hwaddr size;
53      void *data;
54  
55      if (linesize == 0) {
56          linesize = width * PIXMAN_FORMAT_BPP(format) / 8;
57      }
58  
59      size = (hwaddr)linesize * height;
60      data = cpu_physical_memory_map(addr, &size, 0);
61      if (size != (hwaddr)linesize * height) {
62          cpu_physical_memory_unmap(data, size, 0, 0);
63          return NULL;
64      }
65  
66      surface = qemu_create_displaysurface_from(width, height,
67                                                format, linesize, data);
68      pixman_image_set_destroy_function(surface->image,
69                                        ramfb_unmap_display_surface, NULL);
70  
71      return surface;
72  }
73  
74  static void ramfb_fw_cfg_write(void *dev, off_t offset, size_t len)
75  {
76      RAMFBState *s = dev;
77      uint32_t fourcc, format, width, height;
78      hwaddr stride, addr;
79  
80      width     = be32_to_cpu(s->cfg.width);
81      height    = be32_to_cpu(s->cfg.height);
82      stride    = be32_to_cpu(s->cfg.stride);
83      fourcc    = be32_to_cpu(s->cfg.fourcc);
84      addr      = be64_to_cpu(s->cfg.addr);
85      format    = qemu_drm_format_to_pixman(fourcc);
86  
87      fprintf(stderr, "%s: %dx%d @ 0x%" PRIx64 "\n", __func__,
88              width, height, addr);
89      if (s->locked) {
90          fprintf(stderr, "%s: resolution locked, change rejected\n", __func__);
91          return;
92      }
93      s->locked = true;
94      s->width = width;
95      s->height = height;
96      s->ds = ramfb_create_display_surface(s->width, s->height,
97                                           format, stride, addr);
98  }
99  
100  void ramfb_display_update(QemuConsole *con, RAMFBState *s)
101  {
102      if (!s->width || !s->height) {
103          return;
104      }
105  
106      if (s->ds) {
107          dpy_gfx_replace_surface(con, s->ds);
108          s->ds = NULL;
109      }
110  
111      /* simple full screen update */
112      dpy_gfx_update_full(con);
113  }
114  
115  static void ramfb_reset(void *opaque)
116  {
117      RAMFBState *s = (RAMFBState *)opaque;
118      s->locked = false;
119      memset(&s->cfg, 0, sizeof(s->cfg));
120      s->cfg.width = s->starting_width;
121      s->cfg.height = s->starting_height;
122  }
123  
124  RAMFBState *ramfb_setup(DeviceState* dev, Error **errp)
125  {
126      FWCfgState *fw_cfg = fw_cfg_find();
127      RAMFBState *s;
128  
129      if (!fw_cfg || !fw_cfg->dma_enabled) {
130          error_setg(errp, "ramfb device requires fw_cfg with DMA");
131          return NULL;
132      }
133  
134      s = g_new0(RAMFBState, 1);
135  
136      const char *s_fb_width = qemu_opt_get(dev->opts, "xres");
137      const char *s_fb_height = qemu_opt_get(dev->opts, "yres");
138      if (s_fb_width) {
139          s->cfg.width = atoi(s_fb_width);
140          s->starting_width = s->cfg.width;
141      }
142      if (s_fb_height) {
143          s->cfg.height = atoi(s_fb_height);
144          s->starting_height = s->cfg.height;
145      }
146      s->locked = false;
147  
148      rom_add_vga("vgabios-ramfb.bin");
149      fw_cfg_add_file_callback(fw_cfg, "etc/ramfb",
150                               NULL, ramfb_fw_cfg_write, s,
151                               &s->cfg, sizeof(s->cfg), false);
152      qemu_register_reset(ramfb_reset, s);
153      return s;
154  }
155