starnix_modules_framebuffer/
lib.rs

1// Copyright 2022 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#![recursion_limit = "512"]
6
7mod server;
8
9use crate::server::{FramebufferServer, init_viewport_scene, start_presentation_loop};
10use fidl_fuchsia_io as fio;
11use fidl_fuchsia_math as fmath;
12use fidl_fuchsia_ui_composition as fuicomposition;
13use fidl_fuchsia_ui_display_singleton as fuidisplay;
14use fidl_fuchsia_ui_views as fuiviews;
15use fuchsia_component::client::connect_to_protocol_sync;
16use starnix_core::device::kobject::DeviceMetadata;
17use starnix_core::device::{DeviceMode, DeviceOps};
18use starnix_core::mm::MemoryAccessorExt;
19use starnix_core::mm::memory::MemoryObject;
20use starnix_core::task::{CurrentTask, Kernel};
21use starnix_core::vfs::{
22    CloseFreeSafe, FileObject, FileOps, NamespaceNode, fileops_impl_memory, fileops_impl_noop_sync,
23};
24use starnix_logging::{log_info, log_warn, track_stub};
25use starnix_sync::{
26    FramebufferInfoLock, FramebufferMemoryLock, FramebufferViewBoundProtocolsLock,
27    FramebufferViewIdentityLock, LockDepMutex, LockDepRwLock,
28};
29use starnix_syscalls::{SUCCESS, SyscallArg, SyscallResult};
30use starnix_uapi::device_id::DeviceId;
31use starnix_uapi::errors::Errno;
32use starnix_uapi::open_flags::OpenFlags;
33use starnix_uapi::user_address::{MultiArchUserRef, UserAddress};
34use starnix_uapi::{
35    FB_BLANK_POWERDOWN, FB_BLANK_UNBLANK, FB_TYPE_PACKED_PIXELS, FB_VISUAL_TRUECOLOR, FBIOBLANK,
36    FBIOGET_FSCREENINFO, FBIOGET_VSCREENINFO, FBIOPUT_VSCREENINFO, errno, error, fb_bitfield,
37    fb_fix_screeninfo, fb_var_screeninfo, uapi,
38};
39use std::sync::Arc;
40use zerocopy::IntoBytes;
41
42fn get_display_size() -> Result<fmath::SizeU, Errno> {
43    let singleton_display_info =
44        connect_to_protocol_sync::<fuidisplay::InfoMarker>().map_err(|_| errno!(ENOENT))?;
45    let metrics = singleton_display_info
46        .get_metrics(zx::MonotonicInstant::INFINITE)
47        .map_err(|_| errno!(EINVAL))?;
48    let extent_in_px =
49        metrics.extent_in_px.ok_or("Failed to get extent_in_px").map_err(|_| errno!(EINVAL))?;
50    Ok(extent_in_px)
51}
52
53#[derive(Clone, Copy, Debug, Default)]
54pub struct AspectRatio {
55    pub width: u32,
56    pub height: u32,
57}
58
59pub struct Framebuffer {
60    server: Option<Arc<FramebufferServer>>,
61    memory: LockDepMutex<Option<Arc<MemoryObject>>, FramebufferMemoryLock>,
62    pub info: LockDepRwLock<fb_var_screeninfo, FramebufferInfoLock>,
63    pub view_identity:
64        LockDepMutex<Option<fuiviews::ViewIdentityOnCreation>, FramebufferViewIdentityLock>,
65    pub view_bound_protocols:
66        LockDepMutex<Option<fuicomposition::ViewBoundProtocols>, FramebufferViewBoundProtocolsLock>,
67    pub initial_view_id_annotation: String,
68}
69
70impl Framebuffer {
71    /// Returns the current fraembuffer if one was created for this kernel.
72    pub fn get(kernel: &Kernel) -> Result<Arc<Self>, Errno> {
73        kernel.expando.get_or_try_init(|| error!(EINVAL))
74    }
75
76    /// Initialize the framebuffer device. Should only be called once per kernel.
77    pub fn device_init(
78        kernel: &Kernel,
79        aspect_ratio: Option<AspectRatio>,
80        enable_visual_debugging: bool,
81        initial_view_id_annotation: String,
82    ) -> Result<Arc<Framebuffer>, Errno> {
83        let registry = &kernel.device_registry;
84
85        let framebuffer = kernel.expando.get_or_try_init(|| {
86            Framebuffer::new(aspect_ratio, enable_visual_debugging, initial_view_id_annotation)
87        })?;
88
89        let graphics_class = registry.objects.graphics_class();
90        registry.register_device(
91            kernel,
92            "fb0".into(),
93            DeviceMetadata::new("fb0".into(), DeviceId::FB0, DeviceMode::Char),
94            graphics_class,
95            FramebufferDevice { framebuffer: framebuffer.clone() },
96        )?;
97
98        Ok(framebuffer)
99    }
100
101    /// Creates a new `Framebuffer` fit to the screen, while maintaining the provided aspect ratio.
102    ///
103    /// If the `aspect_ratio` is `None`, the framebuffer will be scaled to the display.
104    fn new(
105        aspect_ratio: Option<AspectRatio>,
106        enable_visual_debugging: bool,
107        initial_view_id_annotation: String,
108    ) -> Result<Self, Errno> {
109        let mut info = fb_var_screeninfo::default();
110
111        let display_size = get_display_size().unwrap_or(fmath::SizeU { width: 700, height: 1200 });
112
113        // If the container has a specific aspect ratio set, use that to fit the framebuffer
114        // inside of the display.
115        let (feature_width, feature_height) = aspect_ratio
116            .map(|ar| (ar.width, ar.height))
117            .unwrap_or((display_size.width, display_size.height));
118
119        // Scale to framebuffer to fit the display, while maintaining the expected aspect ratio.
120        let ratio =
121            std::cmp::min(display_size.width / feature_width, display_size.height / feature_height);
122        let (width, height) = (feature_width * ratio, feature_height * ratio);
123
124        info.xres = width;
125        info.yres = height;
126        info.xres_virtual = info.xres;
127        info.yres_virtual = info.yres;
128        info.bits_per_pixel = 32;
129        info.red = fb_bitfield { offset: 0, length: 8, msb_right: 0 };
130        info.green = fb_bitfield { offset: 8, length: 8, msb_right: 0 };
131        info.blue = fb_bitfield { offset: 16, length: 8, msb_right: 0 };
132        info.transp = fb_bitfield { offset: 24, length: 8, msb_right: 0 };
133
134        if let Ok((server, memory)) = FramebufferServer::new(width, height) {
135            let server = Arc::new(server);
136            let memory_len = memory.info()?.size_bytes as u32;
137
138            // Fill the buffer with black pixels as a placeholder, if visual debug is off.
139            // Fill the buffer with purple, if visual debug is on.
140            let background = if enable_visual_debugging {
141                [0xff, 0x00, 0xff, 0xff].repeat((memory_len / 4) as usize)
142            } else {
143                vec![0x00; memory_len as usize]
144            };
145
146            if let Err(err) = memory.write(&background, 0) {
147                log_warn!("could not write initial framebuffer: {:?}", err);
148            }
149
150            Ok(Self {
151                server: Some(server),
152                memory: Some(memory).into(),
153                info: info.into(),
154                view_identity: Default::default(),
155                view_bound_protocols: Default::default(),
156                initial_view_id_annotation,
157            })
158        } else {
159            Ok(Self {
160                server: None,
161                memory: Default::default(),
162                info: info.into(),
163                view_identity: Default::default(),
164                view_bound_protocols: Default::default(),
165                initial_view_id_annotation,
166            })
167        }
168    }
169
170    /// Starts presenting a view based on this framebuffer.
171    ///
172    /// # Parameters
173    /// * `incoming_dir`: the incoming service directory under which the
174    ///   `fuchsia.element.GraphicalPresenter` protocol can be retrieved.
175    pub fn start_server(&self, kernel: &Kernel, incoming_dir: Option<fio::DirectoryProxy>) {
176        if let Some(server) = &self.server {
177            let view_bound_protocols = self.view_bound_protocols.lock().take().unwrap();
178            let view_identity = self.view_identity.lock().take().unwrap();
179            log_info!("Presenting view using GraphicalPresenter");
180            start_presentation_loop(
181                kernel,
182                server.clone(),
183                view_bound_protocols,
184                view_identity,
185                incoming_dir,
186                self.initial_view_id_annotation.clone(),
187            );
188        }
189    }
190
191    /// Starts presenting a child view instead of the framebuffer.
192    ///
193    /// # Parameters
194    /// * `viewport_token`: handles to the child view
195    pub fn present_view(&self, viewport_token: fuiviews::ViewportCreationToken) {
196        if let Some(server) = &self.server {
197            init_viewport_scene(server.clone(), viewport_token);
198
199            // Release the memory associated with the framebuffer.
200            let mut memory = self.memory.lock();
201            if let Some(memory_ref) = memory.as_ref() {
202                let bytes = memory_ref.get_size();
203                let refs = Arc::strong_count(memory_ref);
204                *memory = None;
205                log_info!("Released framebuffer memory ({} bytes, {} refs)", bytes, refs);
206            }
207        }
208    }
209
210    /// Returns the framebuffer's memory.
211    fn get_memory(&self) -> Result<Arc<MemoryObject>, Errno> {
212        self.memory.lock().clone().ok_or_else(|| errno!(EIO))
213    }
214
215    /// Returns the logical size of the framebuffer's memory.
216    fn memory_len(&self) -> usize {
217        self.memory
218            .lock()
219            .as_ref()
220            .map_or(0, |memory| memory.info().map_or(0, |info| info.size_bytes)) as usize
221    }
222
223    /// Returns the allocated size of the framebuffer's memory.
224    fn memory_size(&self) -> usize {
225        self.memory.lock().as_ref().map_or(0, |memory| memory.get_size()) as usize
226    }
227}
228
229#[derive(Clone)]
230struct FramebufferDevice {
231    framebuffer: Arc<Framebuffer>,
232}
233
234type FbFixScreeninfoPtr =
235    MultiArchUserRef<uapi::fb_fix_screeninfo, uapi::arch32::fb_fix_screeninfo>;
236type FbVarScreeninfoPtr =
237    MultiArchUserRef<uapi::fb_var_screeninfo, uapi::arch32::fb_var_screeninfo>;
238
239fn set_display_power(mode: fuidisplay::PowerMode) -> Result<(), Errno> {
240    let singleton_display_power =
241        connect_to_protocol_sync::<fuidisplay::DisplayPowerMarker>().map_err(|_| errno!(ENOENT))?;
242    singleton_display_power
243        .set_power_mode(mode, zx::MonotonicInstant::INFINITE)
244        .map_err(|_| errno!(EIO))?
245        .map_err(|_| errno!(EINVAL))?;
246    Ok(())
247}
248
249impl DeviceOps for FramebufferDevice {
250    fn open(
251        &self,
252        _current_task: &CurrentTask,
253        dev: DeviceId,
254        node: &NamespaceNode,
255        _flags: OpenFlags,
256    ) -> Result<Box<dyn FileOps>, Errno> {
257        if dev.minor() != 0 {
258            return error!(ENODEV);
259        }
260        node.entry.node.update_info(|info| {
261            info.size = self.framebuffer.memory_len();
262            info.blocks = self.framebuffer.memory_size() / info.blksize;
263            Ok(())
264        })?;
265        Ok(Box::new(Arc::clone(&self.framebuffer)))
266    }
267}
268/// `Framebuffer` doesn't implement the `close` method.
269impl CloseFreeSafe for Framebuffer {}
270impl FileOps for Framebuffer {
271    fileops_impl_memory!(self, &self.get_memory()?);
272    fileops_impl_noop_sync!();
273
274    fn ioctl(
275        &self,
276        _file: &FileObject,
277        current_task: &CurrentTask,
278        request: u32,
279        arg: SyscallArg,
280    ) -> Result<SyscallResult, Errno> {
281        let user_addr = UserAddress::from(arg);
282        match request {
283            FBIOGET_FSCREENINFO => {
284                let info = self.info.read();
285                let finfo = fb_fix_screeninfo {
286                    id: zerocopy::FromBytes::read_from_bytes(&b"Starnix\0\0\0\0\0\0\0\0\0"[..])
287                        .unwrap(),
288                    smem_start: 0,
289                    smem_len: self.memory_len() as u32,
290                    type_: FB_TYPE_PACKED_PIXELS,
291                    visual: FB_VISUAL_TRUECOLOR,
292                    line_length: info.bits_per_pixel / 8 * info.xres,
293                    ..fb_fix_screeninfo::default()
294                };
295                let user_ref = FbFixScreeninfoPtr::new(current_task, user_addr);
296                current_task.write_multi_arch_object(user_ref, finfo)?;
297                Ok(SUCCESS)
298            }
299
300            FBIOGET_VSCREENINFO => {
301                let info = self.info.read();
302                let user_ref = FbVarScreeninfoPtr::new(current_task, user_addr);
303                current_task.write_multi_arch_object(user_ref, *info)?;
304                Ok(SUCCESS)
305            }
306
307            FBIOPUT_VSCREENINFO => {
308                let user_ref = FbVarScreeninfoPtr::new(current_task, user_addr);
309                let new_info: fb_var_screeninfo = current_task.read_multi_arch_object(user_ref)?;
310                let old_info = self.info.read();
311                // We don't yet support actually changing anything
312                if new_info.as_bytes() != old_info.as_bytes() {
313                    return error!(EINVAL);
314                }
315                Ok(SUCCESS)
316            }
317
318            FBIOBLANK => {
319                let arg = u32::from(arg);
320                match arg {
321                    FB_BLANK_POWERDOWN => {
322                        set_display_power(fuidisplay::PowerMode::Off)?;
323                        Ok(SUCCESS)
324                    }
325                    FB_BLANK_UNBLANK => {
326                        set_display_power(fuidisplay::PowerMode::On)?;
327                        Ok(SUCCESS)
328                    }
329                    _ => {
330                        track_stub!(TODO("https://fxbug.dev/475633434"), "FBIOBLANK", arg);
331                        error!(EINVAL)
332                    }
333                }
334            }
335
336            _ => {
337                track_stub!(TODO("https://fxbug.dev/475633434"), "fb ioctl", request);
338                error!(EINVAL)
339            }
340        }
341    }
342}
starnix_modules_framebuffer/lib.rs

starnix_modules_framebuffer/
lib.rs
