Add built-in swtfb client and enable musl builds on rM 2 (#78)

Co-authored-by: Pierre Fenoll <pierrefenoll@gmail.com>

.github/workflows/build.yml

@@ -1,8 +1,7 @@
 on: [push, pull_request]
-
 name: Continuous integration
-
 jobs:
+
   check:
     name: Check
     runs-on: ubuntu-latest
@@ -11,33 +10,47 @@ jobs:
     - uses: actions-rs/toolchain@v1
       with:
         profile: minimal
-        toolchain: nightly
-        target: armv7-unknown-linux-gnueabihf
+        toolchain: stable
+        target: ${{ env.TARGET }}
         override: true
         components: rustfmt
     - uses: actions-rs/cargo@v1
       with:
         command: check
         use-cross: true
-        args: --target armv7-unknown-linux-gnueabihf
+        args: --target ${{ env.TARGET }}
 
   test:
-    name: Test Suite
+    name: Test Suite on gnueabihf
     runs-on: ubuntu-latest
+    env:
+      TARGET: armv7-unknown-linux-gnueabihf
     steps:
     - uses: actions/checkout@v2
     - uses: actions-rs/toolchain@v1
       with:
         profile: minimal
-        toolchain: nightly
-        target: armv7-unknown-linux-gnueabihf
+        toolchain: stable
+        target: ${{ env.TARGET }}
         override: true
         components: rustfmt
     - uses: actions-rs/cargo@v1
       with:
         command: test
         use-cross: true
-        args: --target armv7-unknown-linux-gnueabihf
+        args: --target ${{ env.TARGET }}
+  test-local:
+    name: Test Suite
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions-rs/toolchain@v1
+      with:
+        profile: minimal
+        toolchain: stable
+    - uses: actions-rs/cargo@v1
+      with:
+        command: test
 
   fmt:
     name: Rustfmt
@@ -47,8 +60,8 @@ jobs:
     - uses: actions-rs/toolchain@v1
       with:
         profile: minimal
-        toolchain: nightly
-        target: armv7-unknown-linux-gnueabihf
+        toolchain: stable
+        target: ${{ env.TARGET }}
         override: true
         components: rustfmt
     - uses: actions-rs/cargo@v1
@@ -65,11 +78,14 @@ jobs:
       with:
         profile: minimal
         toolchain: stable
-        target: armv7-unknown-linux-gnueabihf
+        target: ${{ env.TARGET }}
         override: true
         components: rustfmt, clippy
     - uses: actions-rs/cargo@v1
       with:
         command: clippy
         use-cross: true
-        args: --target armv7-unknown-linux-gnueabihf -- -D warnings
+        args: --target ${{ env.TARGET }} -- -D warnings
+
+env:
+  TARGET: armv7-unknown-linux-musleabihf

.github/workflows/demo.yml

@@ -3,15 +3,16 @@ name: Build for reMarkable
 jobs:
 
   demo:
-    name: Demo
+    name: Demo with gnueabihf
     runs-on: ubuntu-latest
     env:
       TARGET: armv7-unknown-linux-gnueabihf
     steps:
     - uses: actions/checkout@v2
     - uses: actions-rs/toolchain@v1
       with:
-        toolchain: nightly
+        profile: minimal
+        toolchain: stable
         target: ${{ env.TARGET }}
         override: true
         components: rustfmt
@@ -20,13 +21,6 @@ jobs:
         use-cross: true
         command: build
         args: --target ${{ env.TARGET }} --release --example demo
-    - uses: softprops/action-gh-release@v1
-      if: startsWith(github.ref, 'refs/tags/')
-      with:
-        files: |
-          ./target/${{ env.TARGET }}/release/demo
-      env:
-        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
   demo-with-musl:
     name: Demo with musl
@@ -37,7 +31,8 @@ jobs:
     - uses: actions/checkout@v2
     - uses: actions-rs/toolchain@v1
       with:
-        toolchain: nightly
+        profile: minimal
+        toolchain: stable
         target: ${{ env.TARGET }}
         override: true
         components: rustfmt
@@ -46,3 +41,10 @@ jobs:
         use-cross: true
         command: build
         args: --target ${{ env.TARGET }} --release --example demo
+    - uses: softprops/action-gh-release@v1
+      if: startsWith(github.ref, 'refs/tags/')
+      with:
+        files: |
+          ./target/${{ env.TARGET }}/release/demo
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Cargo.toml

@@ -41,6 +41,11 @@ name = "spy"
 path = "examples/spy.rs"
 crate-type = ["dylib"]
 
+[[example]]
+name = "swtfb_sysv_spy"
+path = "examples/swtfb_sysv_spy.rs"
+crate-type = ["dylib"]
+
 [[example]]
 name = "demo"
 path = "examples/demo.rs"

Makefile

@@ -1,5 +1,5 @@
-# For musl, use: armv7-unknown-linux-musleabihf
-TARGET ?= armv7-unknown-linux-gnueabihf
+# For non-musl, use: armv7-unknown-linux-gnueabihf
+TARGET ?= armv7-unknown-linux-musleabihf
 
 DEVICE_IP ?= '10.11.99.1'
 DEVICE_HOST ?= root@$(DEVICE_IP)
@@ -8,10 +8,10 @@ all: library examples
 
 .PHONY: examples
 examples:
-	cargo build --examples --release --target=$(TARGET)
+	cargo build --examples --release --target=armv7-unknown-linux-gnueabihf
 
 demo:
-	cargo build --example demo --release --target=$(TARGET)
+	cargo build --example demo --release --target=armv7-unknown-linux-gnueabihf
 
 x-demo:
 	cross build --example demo --release --target=$(TARGET)
@@ -22,7 +22,7 @@ deploy-x-demo: x-demo
 	ssh $(DEVICE_HOST) 'RUST_BACKTRACE=1 RUST_LOG=debug ./demo'
 
 bench:
-	cargo build --examples --release --target=$(TARGET) --features "enable-runtime-benchmarking"
+	cargo build --examples --release --target=armv7-unknown-linux-gnueabihf --features "enable-runtime-benchmarking"
 
 .PHONY: docker-env
 docker-env:
@@ -42,10 +42,10 @@ examples-docker: docker-env
 		-v cargo-registry:/home/builder/.cargo/registry \
 		-w /home/builder/libremarkable \
 		rust-build-remarkable:latest \
-		cargo build --examples --release --target=$(TARGET)
+		cargo build --examples --release --target=armv7-unknown-linux-gnueabihf
 
 library:
-	cargo build --release --target=$(TARGET)
+	cargo build --release --target=armv7-unknown-linux-gnueabihf
 
 test:
 	# Notice we aren't using the armv7 target here

README.md

@@ -77,18 +77,19 @@ The `--release` argument is important as this enables optimizations and without
 #### Building with [`cross`](https://github.com/rust-embedded/cross)
 *Building this way does not require reMarkable's toolchain nor building on Ubuntu 16.04 with Docker so setting up should be easier.*
 
+Install `cross` with `cargo install cross`. Make sure the reMarkable toolchain is not in use first.
+
 To build, deploy and run the `demo`, simply:
 ```shell
-make deploy-x-demo
+make TARGET=armv7-unknown-linux-gnueabihf deploy-x-demo
 # This builds with
 #   cross build --example demo --release --target=armv7-unknown-linux-gnueabihf
 # then deploys the demo
 ```
 ##### Using [`musl`](https://musl.libc.org/)
 Make sure to build with `lto = true` otherwise `musl` symbols may be improperly resolved (call to `mmap` fails).
 
-1. Install `cross` with `cargo install cross` (make sure the reMarkable toolchain is not in use first)
-1. Compile with `cross build --example demo --release --target=armv7-unknown-linux-musleabihf` (or `TARGET=armv7-unknown-linux-musleabihf make x-demo`)
-1. Run the demo: `TARGET=armv7-unknown-linux-musleabihf make deploy-x-demo`
+1. Compile with `cross build --example demo --release --target=armv7-unknown-linux-musleabihf` (or `make x-demo`)
+1. Run the demo: `make deploy-x-demo`
 
-**Regarding apps for the rM2**: `musl`-built apps do not write to the framebuffer of rM2 devices as some work is required regarding `LD_PRELOAD` to enable the use of [`rm2fb`](https://github.com/ddvk/remarkable2-framebuffer). In the meantime you should use the `gnueabihf` target.
+**Regarding apps for the rM2**: you will need the [display](https://github.com/ddvk/remarkable2-framebuffer) package from [Toltec](https://toltec-dev.org/). Only the server part though as the client is built into this lib.

examples/swtfb_sysv_spy.rs

@@ -0,0 +1,49 @@
+use libc::{c_int, c_void, key_t, msqid_ds, size_t};
+use redhook::{hook, real};
+
+use libremarkable::framebuffer::swtfb_client;
+
+hook! {
+  unsafe fn msgget(key: key_t, msgflg: c_int) -> c_int => msgget_spy {
+        let res = real!(msgget)(key, msgflg);
+        eprintln!("Spy: msgget({:#x}, {:#x}) => {:#x}", key, msgflg, res);
+        res
+  }
+}
+
+hook! {
+      unsafe fn msgctl(msqid: c_int, cmd: c_int, buf: *mut msqid_ds) -> c_int => msgctl_spy {
+        let res = real!(msgctl)(msqid, cmd, buf);
+        eprintln!("Spy: msgctl({:#x}, {:#x}, {:?}) => {}", msqid, cmd, buf, res);
+        res
+  }
+}
+
+hook! {
+    unsafe fn msgsnd(msqid: c_int, msgp: *const c_void, msgsz: size_t, msgflg: c_int) -> c_int => msgsnd_spy {
+        let res = real!(msgsnd)(msqid, msgp, msgsz, msgflg);
+        eprintln!("Spy: msgsnd({:#x}, {:?}, {}, {:#x}) => {}", msqid, msgp, msgsz, msgflg, res);
+        if msgsz == std::mem::size_of::<swtfb_client::swtfb_update>() {
+            let msg = &*(msgp as *const swtfb_client::swtfb_update);
+                eprintln!("Spy: msgsnd: Message: swt_update.mtype: {:?}, data: ... }}", msg.mtype);
+                let data_str_formatted = match msg.mtype {
+                    swtfb_client::MSG_TYPE::INIT_t => {
+                        format!("...")
+                    },
+                    swtfb_client::MSG_TYPE::UPDATE_t => {
+                        format!("{:?}", msg.data.update)
+                    },
+                    swtfb_client::MSG_TYPE::XO_t => {
+                        format!("{:?}", msg.data.xochitl_update)
+                    },
+                    swtfb_client::MSG_TYPE::WAIT_t => {
+                        format!("{:?}", msg.data.wait_update)
+                    }
+                };
+                eprintln!("Spy: msgsnd: Message: swt_update.data: {}", data_str_formatted);
+        }else {
+            eprintln!("Spy: msgsnd: Error: Message is not sizeof(swtfb_update) (expected {}, got {})", std::mem::size_of::<swtfb_client::swtfb_update>(), msgsz)
+        }
+        res
+  }
+}

src/appctx.rs

@@ -86,7 +86,9 @@ impl<'a> ApplicationContext<'a> {
         on_wacom: fn(&mut ApplicationContext<'_>, WacomEvent),
         on_touch: fn(&mut ApplicationContext<'_>, MultitouchEvent),
     ) -> ApplicationContext<'static> {
-        let framebuffer = Box::new(core::Framebuffer::from_path("/dev/fb0"));
+        let framebuffer = Box::new(core::Framebuffer::from_path(
+            crate::device::CURRENT_DEVICE.get_framebuffer_path(),
+        ));
         let yres = framebuffer.var_screen_info.yres;
         let xres = framebuffer.var_screen_info.xres;
 

src/device.rs

@@ -31,6 +31,22 @@ impl Model {
             Err(ErrorKind::UnknownVersion(machine_name.to_owned()))
         }
     }
+
+    /// Path for gen 1 can be used as long as the rm2fb shim is active:
+    /// LD_PRELOAD="/opt/lib/librm2fb_client.so.1" <YOUR_BINARY> or
+    /// rm2fb-client YOUR_BINARY
+    /// https://github.com/ddvk/remarkable2-framebuffer/
+    /// If `/dev/shm/swtfb.01` is used for the framebuffer, the
+    /// internal swtfb_client will be used. This enables the use
+    /// of musl builds. But the rm2fb server must still be installed.
+    ///
+    /// TODO: Use proper path (needs breaking change for FramebufferBase::from_path() !)
+    pub fn framebuffer_path(&self) -> &'static str {
+        match self {
+            Model::Gen1 => "/dev/fb0",
+            Model::Gen2 => "/dev/shm/swtfb.01",
+        }
+    }
 }
 
 pub static CURRENT_DEVICE: Lazy<Device> = Lazy::new(Device::new);
@@ -118,4 +134,8 @@ impl Device {
             Model::Gen2 => "max77818_battery",
         }
     }
+
+    pub fn get_framebuffer_path(&self) -> &'static str {
+        self.model.framebuffer_path()
+    }
 }