Add libxkbcommon as a submodule

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "firmware2/libxkbcommon"]
+	path = firmware2/libxkbcommon
+	url = https://github.com/xkbcommon/libxkbcommon

firmware2/.cargo/config.toml

@@ -12,6 +12,7 @@ rustflags = [
 
 
 [env]
+LIBXKBCOMMON_BUILD_DIR = "libxkbcommon/build"
 ESP_LOG = "warn"
 # This is overkill, but we can afford it.
 SLINT_FONT_SIZES = "8,11,10,12,13,14,15,16,18,20,22,24,32"

firmware2/Cargo.lock

@@ -31,6 +31,7 @@ dependencies = [
  "esp-storage",
  "gix",
  "i-slint-common",
+ "indoc",
  "itertools 0.14.0",
  "json",
  "lazy_static",

firmware2/Cargo.toml

@@ -85,6 +85,7 @@ embuild = "0.33"
 cc = "1.2.9"
 slint-build = "1.14.1"
 gix = { version = "0.76.0", default-features = false, features = ["max-performance", "status"] }
+indoc = "2.0.7"
 
 [[bin]]
 name = "acid-firmware"

firmware2/README.md

@@ -4,28 +4,46 @@
 
 ### Compiling libxkbcommon
 
+Before compiling the firmware itself, its C dependencies must be compiled separately first.
 This needs to be done on Linux or in WSL.
-meson.build needs to be changed such that `pkgconfig.generate` is called with the `variables` field embedded directly, for some reason:
-
-```meson
-    variables: [
-        f'xkb_root=@XKB_CONFIG_ROOT@',
-        f'xkb_extra_path=@XKB_CONFIG_EXTRA_PATH@',
-    ],
-```
-
-Then, the tests, fuzzes and benches need to be commented out.
-Afterwards, the following command should succeed in building the static library in debug mode:
+Download and install [`eim`, the ESP-IDF Installation Manager](github.com/espressif/idf-im-ui/releases/latest).
+Enable the ESP-IDF using:
 
 ```sh
-meson setup build-debug -Denable-x11=false -Dxkb-config-root=/usr/share/X11/xkb -Dx-locale-root=/usr/share/X11/locale -Denable-wayland=false --cross-file cross-esp32s3.txt -Denable-xkbregistry=false -Denable-docs=false -Denable-tools=false --wipe --buildtype=debug
-meson compile -C build-debug
+eim select
 ```
 
-Afterwards, a static library with redefined externally-linked symbols needs to be generated:
+Compile the libxkbcommon library.
 
+```sh
+./libxkbcommon-compile.sh build
 ```
-path/to/root/libxkbcommon-redefine-syms.sh build-debug/libxkbcommon{,_redefined_syms}.a
+
+### Compiling the firmware
+
+To compile the firmware, run:
+```ps1
+cargo build --release
+```
+
+If you wish to download the firmware on the keyboard, the following command can be used:
+```ps1
+cargo run --release -- --port=[PORT]
+```
+where `[PORT]` shall be replaced by a serial port such as `COM5`.
+
+## Building for development
+
+The following arguments are useful to build the libxkbcommon library for debugging.
+```sh
+./libxkbcommon-compile.sh build-debug --buildtype=debug -Dc_args="-fdebug-prefix-map=@GLOBAL_SOURCE_ROOT@=[PATH_TO_LIBRARY_ON_WINDOWS]"
+```
+where `[PATH_TO_LIBRARY_ON_WINDOWS]` is the path to the libxkbcommon submodule on Windows.
+This replaces the debugging symbols with paths that will be available when debugging on Windows.
+
+Then compile the firmware with:
+```ps1
+$env:LIBXKBCOMMON_BUILD_DIR="libxkbcommon/build-debug"; cargo build
 ```
 
 ### Creating keymaps

firmware2/build.rs

@@ -1,20 +1,17 @@
 use std::env;
 use std::fs::{File, OpenOptions};
 use std::io::{Read, Write};
-use std::path::Path;
+use std::path::{Path, PathBuf};
 
 use const_gen::*;
+use indoc::formatdoc;
 use json::JsonValue;
 use slint_build::{CompilerConfiguration, EmbedResourcesKind};
 use xz2::read::XzEncoder;
 
 fn main() {
-    if let Ok(repo) = gix::discover(
-        env::var_os("CARGO_MANIFEST_DIR")
-            .unwrap()
-            .into_string()
-            .unwrap(),
-    ) {
+    let manifest_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
+    if let Ok(repo) = gix::discover(&manifest_dir) {
         let commit_hash = repo.head_commit().unwrap().short_id().unwrap();
         println!("cargo:rustc-env=GIT_COMMIT_HASH={}", commit_hash);
         println!(
@@ -36,22 +33,27 @@ fn main() {
     // println!("cargo:rustc-link-arg=-Tdefmt.x");
 
     // TODO: Make it a submodule and use relative paths.
-    //
-    // 1. Tell cargo where to find the library
-    // let lib_path = PathBuf::from(manifest_dir).join("libs");
-    // println!(r#"cargo:rustc-link-search=native={}"#, lib_path.display());
-    println!(
-        r#"cargo:rustc-link-search=native=C:\Users\Limeth\workspace\c\libxkbcommon-linux\build-debug-redefined-syms"#
-    );
 
-    // 2. Link the static library (strip the 'lib' prefix and '.a' extension)
+    // Link libxkbcommon.
+    let libxkbcommon_build_dir = env::var("LIBXKBCOMMON_BUILD_DIR")
+        .expect("The build directory of libxkbcommon must be specified using the `LIBXKBCOMMON_BUILD_DIR` environment variable.");
+    let libxkbcommon_library_path = PathBuf::from(&libxkbcommon_build_dir).join("libxkbcommon.a");
+
+    if !libxkbcommon_library_path.is_file() {
+        panic!(
+            "{}",
+            formatdoc! {"
+                The compiled libxkbcommon library was not found at path {libxkbcommon_library_path:?}.
+                Most likely, the library was not compiled. See the `README.md` for compilation instructions.
+                If the `LIBXKBCOMMON_BUILD_DIR` environment variable is not set to the build directory you want to use, change it.
+                Currently, `LIBXKBCOMMON_BUILD_DIR` is set to: {libxkbcommon_build_dir}
+            "}
+        );
+    }
+
+    println!("cargo:rustc-link-search=native={libxkbcommon_build_dir}");
     println!("cargo:rustc-link-lib=static=xkbcommon");
-
-    // 3. Re-run if build.rs or the library changes
-    // println!(r#"cargo:rerun-if-changed=C:\Users\Limeth\workspace\c\libxkbcommon-linux\build-debug\libxkbcommon.a"#);
-    println!(
-        r#"cargo:rerun-if-changed=C:\Users\Limeth\workspace\c\libxkbcommon-linux\build-debug-redefined-syms\libxkbcommon.a"#
-    );
+    println!("cargo:rerun-if-changed={libxkbcommon_build_dir}/libxkbcommon.a");
 
     // Slint config and compilation
     {
@@ -62,7 +64,8 @@ fn main() {
             // .with_scale_factor(2.0)
             .with_style("cosmic-dark".to_string())
             .embed_resources(EmbedResourcesKind::EmbedForSoftwareRenderer);
-        slint_build::compile_with_config("ui/main.slint", slint_config).expect("Slint build failed");
+        slint_build::compile_with_config("ui/main.slint", slint_config)
+            .expect("Slint build failed");
         slint_build::print_rustc_flags().unwrap()
     }
 }

firmware2/cross-esp32s3.txt

@@ -4,25 +4,24 @@ cpp = 'xtensa-esp32s3-elf-g++'
 ar = 'xtensa-esp32s3-elf-ar'
 strip = 'xtensa-esp32s3-elf-strip'
 
-[build_machine]
-system = 'linux'
-cpu_family = 'x86_64'
-cpu = 'x86_64'
-endian = 'little'
+# It seems like this is not necessary:
+#[build_machine]
+#system = 'linux'
+#cpu_family = 'x86_64'
+#cpu = 'x86_64'
+#endian = 'little'
 
 [host_machine]
-system = 'bare-metal'     # Crucial: prevents Meson from assuming a POSIX environment
+system = 'none'
 cpu_family = 'xtensa'
 cpu = 'esp32s3'
 endian = 'little'
 
 [built-in options]
 c_args = [
-    '-fdebug-prefix-map=@GLOBAL_SOURCE_ROOT@=C:/Users/Limeth/workspace/c/libxkbcommon-linux',
     '-ffreestanding',
     '-fno-builtin',
     '-mlongcalls',
-    '-mfix-esp32-psram-cache-issue',
     # Manually define the missing inttypes.h macros
     '-DPRId64="lld"',
     '-DPRIu64="llu"',
@@ -35,5 +34,4 @@ c_link_args = [
     '-nostdlib',
     '-static'
     ]
-# Ensure we only build static libraries for bare-metal
 default_library = 'static'

firmware2/libxkbcommon

@@ -0,0 +1 @@
+Subproject commit db1f61ca9a3a3bb05f28550227ca3419e8a22c90

firmware2/libxkbcommon-compile.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+if [ "$#" -lt 1 ]; then
+    echo "Usage: $0 <build-directory-name> [args-passed-to-meson-setup]..."
+    exit 1
+fi
+
+SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+LIBXKBCOMMON_DIR="$SCRIPT_DIR/libxkbcommon"
+BUILD_DIR_NAME="$LIBXKBCOMMON_DIR/$1"
+STATIC_LIB_PATH="$BUILD_DIR_NAME/libxkbcommon.a"
+SETUP_ARGS=${@:2}
+
+git submodule update --init --recursive
+pushd "$LIBXKBCOMMON_DIR" >/dev/null
+    meson setup "$BUILD_DIR_NAME" \
+        --wipe \
+        --cross-file "$SCRIPT_DIR/cross-esp32s3.txt" \
+        -Denable-x11=false \
+        -Denable-wayland=false \
+        -Denable-xkbregistry=false \
+        -Denable-docs=false \
+        -Denable-tools=false \
+        -Dxkb-config-root=/usr/share/X11/xkb \
+        -Dx-locale-root=/usr/share/X11/locale \
+        $SETUP_ARGS
+    meson compile -C "$BUILD_DIR_NAME"
+    $SCRIPT_DIR/libxkbcommon-redefine-syms.sh "$STATIC_LIB_PATH" "$STATIC_LIB_PATH"
+popd >/dev/null
+
+GREEN='\033[0;32m'
+RESET='\033[0m'
+echo -e "${GREEN}Successfully compiled libxkbcommon. Path to static library:\n$STATIC_LIB_PATH${RESET}"

firmware2/libxkbcommon-redefine-syms.sh

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 INPUT_LIB=$1
 OUTPUT_LIB=$2
 PREFIX="__xkbc_"
@@ -11,10 +11,14 @@ fi
 echo "Redefining symbols from $INPUT_LIB into $OUTPUT_LIB..."
 
 xtensa-esp-elf-objcopy --redefine-syms=<(
+    # Perform set subtraction of undefined symbols and defined symbols, to get globally undefined symbols.
     comm -23 \
-        <(xtensa-esp-elf-nm -u "$INPUT_LIB" | awk '{print $NF}' | sort -u) \
+        <(xtensa-esp-elf-nm --undefined-only "$INPUT_LIB" | awk '{print $NF}' | sort -u) \
         <(xtensa-esp-elf-nm --defined-only "$INPUT_LIB" | awk '{print $NF}' | sort -u) | \
+    # Do not prefix already prefixed symbols (idempotency)
+    grep -v "^${PREFIX}" | \
+    # Print each symbol followed by the symbol with the prefix
     awk -v p="$PREFIX" '{print $1 " " p $1}'
 ) "$INPUT_LIB" "$OUTPUT_LIB"
 
-echo "Done! Prefixed all externally linked symbols with $PREFIX."
+echo "Prefixed all externally linked symbols in $INPUT_LIB with $PREFIX, and written the result to: $OUTPUT_LIB"

firmware2/src/ffi/inout/mod.rs

@@ -56,6 +56,11 @@ pub unsafe extern "C" fn __xkbc_fread(
     todo!()
 }
 
+#[unsafe(no_mangle)]
+unsafe extern "C" fn __xkbc_fputs(s: *const c_char, stream: *mut FILE) -> c_int {
+    todo!()
+}
+
 // Printing
 
 #[unsafe(no_mangle)]