Add Android build and APK injection scripts

script/inject.sh

@@ -0,0 +1,166 @@
+#!/bin/bash
+# Script to patch and sign the reMarkable Android APKs
+
+set -euo pipefail
+
+PROJECT_DIR=$(cd "$(dirname "$0")/.." && pwd)
+BUILD_DIR="$PROJECT_DIR/build"
+OUTPUT_DIR="$PROJECT_DIR/output"
+LIBS_DIR="$PROJECT_DIR/libs"
+
+# --- Auto-detect Android SDK build tools ---
+find_build_tools() {
+    local sdk_root="${ANDROID_SDK_ROOT:-$HOME/Library/Android/sdk}"
+    local bt
+    bt=$(find "$sdk_root/build-tools" -maxdepth 1 -type d 2>/dev/null | sort -V | tail -1)
+    if [ -n "$bt" ] && [ -d "$bt" ]; then
+        echo "$bt"; return
+    fi
+    echo ""
+}
+
+BUILD_TOOLS="${ANDROID_SDK_BUILD_TOOLS:-$(find_build_tools)}"
+if [ -z "$BUILD_TOOLS" ] || [ ! -d "$BUILD_TOOLS" ]; then
+    echo "❌ Android SDK build-tools not found."
+    echo "   Set ANDROID_SDK_BUILD_TOOLS to your build-tools path."
+    exit 1
+fi
+
+ZIPALIGN="$BUILD_TOOLS/zipalign"
+APKSIGNER="$BUILD_TOOLS/apksigner"
+
+KEYSTORE="$PROJECT_DIR/config/rmhook.keystore"
+KEYSTORE_PASS="rmhook"
+KEY_ALIAS="rmhook"
+
+usage() {
+    echo "Usage: $0 [apk_dir]"
+    echo ""
+    echo "  apk_dir  - Directory containing the split APKs (default: ~/reMarkable/app)"
+    echo ""
+    echo "Output: patched APKs in $OUTPUT_DIR/"
+    exit 1
+}
+
+APK_DIR="${1:-$HOME/reMarkable/app}"
+
+echo "💉 Injecting RMHook into reMarkable APKs..."
+echo "📦 APK source: $APK_DIR"
+echo ""
+
+if [ ! -f "$BUILD_DIR/librmhook.so" ]; then
+    echo "❌ librmhook.so not found. Run ./script/build.sh first."
+    exit 1
+fi
+
+# Clean and create output directory
+rm -rf "$OUTPUT_DIR"
+mkdir -p "$OUTPUT_DIR"
+
+# --- Step 1: Decompile and patch base.apk (smali injection only, no resources) ---
+echo "[1/4] Patching base.apk (smali injection)..."
+# Use -r (--no-res) to skip decoding/recoding resources. We only need to modify the DEX.
+apktool d -r "$APK_DIR/base.apk" -o "$BUILD_DIR/base" -f
+
+MAIN_SMALI="$BUILD_DIR/base/smali/com/remarkable/mobile/MainActivity.smali"
+if [ ! -f "$MAIN_SMALI" ]; then
+    echo "❌ MainActivity.smali not found"
+    exit 1
+fi
+
+# Insert System.loadLibrary("rmhook") at the very start of <clinit>
+sed -i '' '/.method static constructor <clinit>()V/{
+n
+/.locals/{
+a\
+\
+    const-string v0, "rmhook"\
+\
+    invoke-static {v0}, Ljava/lang/System;->loadLibrary(Ljava/lang/String;)V
+}
+}' "$MAIN_SMALI"
+
+echo "✅ Injected System.loadLibrary(\"rmhook\") into MainActivity.<clinit>"
+
+apktool b "$BUILD_DIR/base" -o "$BUILD_DIR/base_patched.apk"
+
+# --- Step 2: Patch split_config.arm64_v8a.apk (add hook library) ---
+echo "[2/4] Injecting ShadowHook libraries into arm64 split..."
+SPLIT_ARM64="$APK_DIR/split_config.arm64_v8a.apk"
+if [ ! -f "$SPLIT_ARM64" ]; then
+    echo "❌ $SPLIT_ARM64 not found"
+    exit 1
+fi
+
+mkdir -p "$BUILD_DIR/split_arm64"
+unzip -q "$SPLIT_ARM64" -d "$BUILD_DIR/split_arm64"
+
+cp "$BUILD_DIR/librmhook.so" "$BUILD_DIR/split_arm64/lib/arm64-v8a/"
+cp "$LIBS_DIR/libshadowhook_nothing.so" "$BUILD_DIR/split_arm64/lib/arm64-v8a/"
+
+rm -rf "$BUILD_DIR/split_arm64/META-INF"
+
+(cd "$BUILD_DIR/split_arm64" && zip -q -r -0 "$BUILD_DIR/split_arm64_raw.apk" . -x "*.so")
+(cd "$BUILD_DIR/split_arm64" && zip -q -r "$BUILD_DIR/split_arm64_raw.apk" lib/)
+
+# --- Step 3: Align APKs ---
+echo "[3/4] Aligning APKs..."
+"$ZIPALIGN" -p -f 4 "$BUILD_DIR/base_patched.apk" "$BUILD_DIR/base_aligned.apk"
+"$ZIPALIGN" -p -f 4 "$BUILD_DIR/split_arm64_raw.apk" "$BUILD_DIR/split_arm64_aligned.apk"
+
+SPLIT_XXHDPI="$APK_DIR/split_config.xxhdpi.apk"
+if [ -f "$SPLIT_XXHDPI" ]; then
+    mkdir -p "$BUILD_DIR/split_xxhdpi"
+    unzip -q "$SPLIT_XXHDPI" -d "$BUILD_DIR/split_xxhdpi"
+    rm -rf "$BUILD_DIR/split_xxhdpi/META-INF"
+    (cd "$BUILD_DIR/split_xxhdpi" && zip -q -r -0 "$BUILD_DIR/split_xxhdpi_raw.apk" .)
+    "$ZIPALIGN" -p -f 4 "$BUILD_DIR/split_xxhdpi_raw.apk" "$BUILD_DIR/split_xxhdpi_aligned.apk"
+fi
+
+# --- Step 4: Sign all APKs ---
+echo "[4/4] Signing APKs..."
+
+if [ ! -f "$KEYSTORE" ]; then
+    mkdir -p "$(dirname "$KEYSTORE")"
+    echo "🔑 Generating signing keystore..."
+    keytool -genkeypair -v \
+        -keystore "$KEYSTORE" \
+        -alias "$KEY_ALIAS" \
+        -keyalg RSA -keysize 2048 \
+        -validity 10000 \
+        -storepass "$KEYSTORE_PASS" \
+        -keypass "$KEYSTORE_PASS" \
+        -dname "CN=RMHook, OU=Dev, O=RMHook, L=Unknown, ST=Unknown, C=US" \
+        2>/dev/null
+fi
+
+sign_apk() {
+    local input="$1"
+    local output="$2"
+    "$APKSIGNER" sign \
+        --ks "$KEYSTORE" \
+        --ks-pass "pass:$KEYSTORE_PASS" \
+        --ks-key-alias "$KEY_ALIAS" \
+        --key-pass "pass:$KEYSTORE_PASS" \
+        --out "$output" \
+        "$input"
+}
+
+sign_apk "$BUILD_DIR/base_aligned.apk" "$OUTPUT_DIR/base.apk"
+sign_apk "$BUILD_DIR/split_arm64_aligned.apk" "$OUTPUT_DIR/split_config.arm64_v8a.apk"
+if [ -f "$BUILD_DIR/split_xxhdpi_aligned.apk" ]; then
+    sign_apk "$BUILD_DIR/split_xxhdpi_aligned.apk" "$OUTPUT_DIR/split_config.xxhdpi.apk"
+fi
+
+echo ""
+echo "✅ Injection successful!"
+echo "📍 Patched APKs in: $OUTPUT_DIR/"
+ls -lh "$OUTPUT_DIR/"*.apk
+echo ""
+echo "🚀 To install on your reMarkable:"
+echo "   adb uninstall com.remarkable.mobile"
+echo "   adb install-multiple --no-streaming $OUTPUT_DIR/base.apk $OUTPUT_DIR/split_config.arm64_v8a.apk $OUTPUT_DIR/split_config.xxhdpi.apk"
+echo ""
+echo "🔍 To debug:"
+echo "   adb logcat -s 'RMHook:*'"
+echo ""