builders_rubenslte/build_twrp.sh

#!/usr/bin/env bash
# Build a TWRP recovery image for the Samsung Galaxy Tab Active SM-T365
# (codename rubenslte, msm8226).
#
# Usage:
#   ./build_twrp.sh            build recovery.img (default)
#   ./build_twrp.sh --no-sync  skip repo sync / tree updates (fast iteration)
#   ./build_twrp.sh clean      remove twrp-build/ and recovery.img
#   ./build_twrp.sh env        drop into the interactive nix-shell build env
#
# The build runs inside the nix-shell FHS environment defined in shell.nix.
# `nix-shell --run` cannot be relied on here, so when invoked from the host the
# script re-executes itself *inside* the env via a stdin pipe
# (RUBENSLTE_BUILD_IN_ENV prevents infinite recursion).
set -euo pipefail

SCRIPT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
cd "$SCRIPT"

RECOVERY_PARTITION_SIZE=10485248

MANIFEST_URL="https://github.com/minimal-manifest-twrp/platform_manifest_twrp_omni.git"
MANIFEST_BRANCH="twrp-5.1"
DEVICE_TREE_URL="https://git.cfpi-fpsi.eu/rubenslte/twrp_device_samsung_rubenslte"
KERNEL_URL="https://git.cfpi-fpsi.eu/rubenslte/android_kernel_samsung_rubenslte"
TOOLCHAIN_URL="https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/arm/arm-eabi-4.8/+archive/refs/tags/android-5.1.1_r38.tar.gz"
TOOLCHAIN_DIR="prebuilts/gcc/linux-x86/arm/arm-eabi-4.8"

usage() {
    sed -n '2,9p' "$0" | sed 's/^# \{0,1\}//'
}

reenter_build_env() {
    if [ -z "${RUBENSLTE_BUILD_IN_ENV:-}" ]; then
        echo "[*] Re-entering build inside the nix-shell FHS environment ..."
        printf 'export RUBENSLTE_BUILD_IN_ENV=1\nbash "%s"\n' "$SCRIPT/build_twrp.sh" \
            | nix-shell shell.nix
        exit $?
    fi
}

clone_or_update() {
    local name="$1" url="$2" dest="$3"
    if [ ! -d "$dest/.git" ]; then
        echo "[*] Cloning $name ..."
        git clone -q --depth 1 "$url" "$dest"
    else
        echo "[*] Updating $name ..."
        local branch
        branch="$(git -C "$dest" rev-parse --abbrev-ref HEAD)"
        git -C "$dest" fetch -q --depth 1 origin "$branch"
        git -C "$dest" reset -q --hard "origin/$branch"
    fi
}

apply_patches() {
    local p log
    for p in "$SCRIPT"/patches/*.patch; do
        log="$(mktemp)"
        if patch -p1 -s < "$p" >"$log" 2>&1; then
            echo "[*] Applied patch: $(basename "$p")"
        elif grep -q -E 'Reversed|already applied' "$log"; then
            echo "[*] Patch already applied: $(basename "$p")"
        else
            echo "[!] WARNING: patch failed: $(basename "$p")"
            cat "$log"
        fi
        rm -f "$log"
    done
}

fetch_toolchain() {
    if [ -x "$TOOLCHAIN_DIR/bin/arm-eabi-gcc" ]; then
        return
    fi
    echo "[*] Downloading arm-eabi-4.8 prebuilt toolchain ..."
    mkdir -p "$TOOLCHAIN_DIR"
    curl -L --fail "$TOOLCHAIN_URL" | tar -xz -C "$TOOLCHAIN_DIR"
}

verify_image() {
    local img="$1"
    [ -f "$img" ] || { echo "ERROR: $img was not produced" >&2; exit 1; }
    local size
    size="$(stat -c%s "$img")"
    echo "[*] $img: $size bytes (partition budget: $RECOVERY_PARTITION_SIZE)"
    if [ "$size" -gt "$RECOVERY_PARTITION_SIZE" ]; then
        echo "ERROR: image exceeds the recovery partition" >&2
        exit 1
    fi
    sha256sum "$img"
    echo "Done: $img"
}

do_build() {
    export LC_ALL=C LANG=C LC_CTYPE=C

    mkdir -p twrp-build
    cd twrp-build

    if [ ! -d .repo ]; then
        repo init --depth 1 -u "$MANIFEST_URL" -b "$MANIFEST_BRANCH"
    fi
    if [ "$NO_SYNC" -eq 0 ]; then
        repo sync -c -j"$(nproc)"
        clone_or_update "device tree" "$DEVICE_TREE_URL" device/samsung/rubenslte
        clone_or_update "kernel" "$KERNEL_URL" kernel/samsung/rubenslte
        apply_patches
    fi

    fetch_toolchain
    export PATH="$PWD/$TOOLCHAIN_DIR/bin:$PATH"

    export TOP="$PWD"
    set +u
    source build/envsetup.sh
    lunch omni_rubenslte-userdebug
    set -u
    mka recoveryimage

    cp out/target/product/rubenslte/recovery.img "$SCRIPT/"
    verify_image "$SCRIPT/recovery.img"
}

do_clean() {
    rm -rf twrp-build recovery.img
}

do_env() {
    exec nix-shell shell.nix
}

cmd="${1:-build}"
case "$cmd" in
    clean) shift 2>/dev/null || true ;;
    env) shift 2>/dev/null || true ;;
    build) shift 2>/dev/null || true ;;
    --*) cmd=build ;;
    *) usage >&2; exit 2 ;;
esac

NO_SYNC=0
for a in "$@"; do
    case "$a" in
        --no-sync) NO_SYNC=1 ;;
        *) usage >&2; exit 2 ;;
    esac
done

case "$cmd" in
    build) reenter_build_env; do_build ;;
    clean) do_clean ;;
    env) do_env ;;
esac