#!/usr/bin/env bash
# SPDX-License-Identifier: (GPL-2.0-only OR MIT)
# Copyright (C) 2026 Amlogic, Inc. All rights reserved
################################################################################
# Amlbian Gpu Compilation Module
#
# Purpose: Gpu compilation with Hook support and aml-comp integration
# Provides: Gpu compilation, post-kernel driver preparation
################################################################################

set -e

# Get script directory And Set env
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
AMLBIAN_DIR="$(dirname "$(dirname "${SCRIPT_DIR}")")"
BASE_DIR="$(dirname "$(dirname "${AMLBIAN_DIR}")")"
GPU_MODE="${GPU_MODE:-vale}"
GPU_ARCH="${GPU_ARCH:-valhall}"

# Source common functions
if [[ -f "${AMLBIAN_DIR}/lib/function-common.sh" ]]; then
    source "${AMLBIAN_DIR}/lib/function-common.sh"
fi

# ==============================================================================
# Shared Helper Functions
# ==============================================================================

# ------------------------------------------------------------------------------
# Step 1: Version and Package Information Definition
# ------------------------------------------------------------------------------

# Initialize common package metadata for Mali GPU (libgles)
function _gpu_libgles_init_package_info() {
    PKG_MAINTAINER="Armbian Build <build@armbian.com>"
    PKG_DESCRIPTION="OpenGL ES driver for Amlogic GPU with Wayland DRM support"
    PKG_NAME="aml-libgles-eabihf-${GPU_MODE}-wayland-drm"
    PKG_VERSION="1.0-r54p1"
    PKG_ARCH="arm64"
    LIB_DIR="aarch64-linux-gnu"
    MALI_ARCH="arm64"
    FILES_DIR="${SCRIPT_DIR}/files"
    VENDOR_DIR="${BASE_DIR}/aml-comp/vendor/amlogic/meson_mali"

    # 本包用软链把下列路径指向 libMali.so，其中多数同时属于 mesa/libglvnd
    # (libgbm1/libgbm-dev/libegl1/libgles1/libgles2)。必须用 dpkg-divert 把
    # mesa 的实体让开，否则 mesa 一升级 dpkg 就报 trying to overwrite。
    MESA_DIVERT_FILES="libgbm.so libgbm.so.1 libgbm.so.1.0.0 \
libEGL.so libEGL.so.1 libEGL.so.1.4.0 \
libGLESv2.so libGLESv2.so.2 libGLESv2.so.2.1.0 \
libGLESv1_CM.so libGLESv1_CM.so.1 libGLESv1_CM.so.1.1.0"

    # 必须在 ldconfig 搜索路径之外。若把 mesa 的 libgbm.so.1.0.0 留在
    # /usr/lib/${LIB_DIR} 下(哪怕改名)，ldconfig 会按 SONAME 把 libgbm.so.1
    # 抢回去指向 mesa —— libMali.so 的 SONAME 是 libMali.so，ldconfig 不认它
    # 是 libgbm.so.1 的提供者。/usr/lib 的子目录不会被 ldconfig 递归扫描。
    MESA_DIVERT_DIR="/usr/lib/mesa-gbm-diverted"
}

# Initialize common package metadata for kernel module
function _gpu_kernel_init_package_info() {
    PKG_MAINTAINER="Armbian Build <build@armbian.com>"
    PKG_DESCRIPTION="GPU kernel modules for Amlogic SoCs"
    PKG_NAME="aml-gpu-${GPU_ARCH}-kernel"
    DIR_VERSION="r54p1"
    PKG_VERSION="1.0-r54p1"
    GPU_LOW_MEM="${GPU_LOW_MEM:-0}"

    PKG_ARCH="arm64"
    LIB_DIR="aarch64-linux-gnu"
    MALI_ARCH="arm64"
}

# ------------------------------------------------------------------------------
# Step 2: Build Directory Structure Setup
# ------------------------------------------------------------------------------

# Create layered build directory structure
# Parameters:
#   $1 - base name (e.g. "${PKG_NAME}_${PKG_VERSION}_${PKG_ARCH}")
# Sets: TMP_DIR, BASE_BUILD_DIR, SOURCE_DIR, BUILD_DIR, INSTALL_DIR, PATCH_DIR,
#       DEB_PACKAGE_DIR, DEBIAN_DIR
function _gpu_create_build_dirs() {
    local base_name="$1"

    TMP_DIR="${AMLBIAN_DIR}/.tmp"
    mkdir -p "${TMP_DIR}"

    # 基础构建目录
    BASE_BUILD_DIR="${TMP_DIR}/${base_name}"

	rm -rf ${BASE_BUILD_DIR}
    # 分层目录
    SOURCE_DIR="${BASE_BUILD_DIR}/source"      # 源码目录
    BUILD_DIR="${BASE_BUILD_DIR}/build"        # 编译目录
    INSTALL_DIR="${BASE_BUILD_DIR}/install"    # 安装目录
    PATCH_DIR="${BASE_BUILD_DIR}/patch"        # 补丁目录

    # 创建所有目录
    mkdir -p "${SOURCE_DIR}"
    mkdir -p "${BUILD_DIR}"
    mkdir -p "${INSTALL_DIR}"
    mkdir -p "${PATCH_DIR}"

    # 在BUILD_DIR下创建deb/包名目录
    DEB_PACKAGE_DIR="${BUILD_DIR}/deb/${base_name}"
    mkdir -p "${DEB_PACKAGE_DIR}"

    # 安装目录的子目录
    DEBIAN_DIR="${INSTALL_DIR}/DEBIAN"
    mkdir -p "${DEBIAN_DIR}"
}

# Create standard install subdirectories for Mali GPU libraries
function _gpu_libgles_create_install_dirs() {
    mkdir -p "${INSTALL_DIR}/usr/include"
    mkdir -p "${INSTALL_DIR}/usr/lib/${LIB_DIR}"
    mkdir -p "${INSTALL_DIR}/usr/lib/pkgconfig"
    mkdir -p "${INSTALL_DIR}/usr/share/vulkan/icd.d"
    mkdir -p "${INSTALL_DIR}/usr/share/vulkan/implicit_layer.d"
    mkdir -p "${INSTALL_DIR}/lib/firmware"
    mkdir -p "${INSTALL_DIR}/etc"
}

# ------------------------------------------------------------------------------
# Step 3: Debian Packaging Scripts Creation
# ------------------------------------------------------------------------------

# Create Debian control file
# Parameters:
#   $1 - package name
#   $2 - package version
#   $3 - package architecture
#   $4 - maintainer
#   $5 - description
#   $6 - dependencies (optional)
#   $7 - conflicts (optional)
#   $8 - provides (optional)
#   $9 - section (optional, default "libs")
function _gpu_create_control_file() {
    local pkg_name="$1"
    local pkg_version="$2"
    local pkg_arch="$3"
    local maintainer="$4"
    local description="$5"
    local depends="${6:-}"
    local conflicts="${7:-}"
    local provides="${8:-}"
    local section="${9:-libs}"
    local replaces="${10:-}"

    display_alert "COMPILE-GPU Creating control file DEBIAN/control" "info"
    cat > "${DEBIAN_DIR}/control" <<EOF
Package: ${pkg_name}
Version: ${pkg_version}
Architecture: ${pkg_arch}
Maintainer: ${maintainer}
Depends: ${depends}
Conflicts: ${conflicts}
Provides: ${provides}
Section: ${section}
Priority: optional
EOF
    # Replaces 只在非空时写入。不要加 Conflicts: libgbm1 —— mesa 各包对它是
    # 精确版本依赖，Conflicts 会导致 apt 连带卸掉整套 mesa/gnome。
    if [[ -n "${replaces}" ]]; then
        echo "Replaces: ${replaces}" >> "${DEBIAN_DIR}/control"
    fi
    cat >> "${DEBIAN_DIR}/control" <<EOF
Description: ${description}
EOF
}

# Create preinst script for Mali GPU libraries
#
# 在解包之前把 mesa 拥有的同名文件 divert 走，本包的软链才能干净地占用真实
# 路径；之后 mesa 再升级，它的文件会落到 ${MESA_DIVERT_DIR}，不会覆盖 Mali。
function _gpu_libgles_create_preinst() {
    display_alert "COMPILE-GPU Creating pre-installation script DEBIAN/preinst" "info"
    cat > "${DEBIAN_DIR}/preinst" << EOF
#!/bin/sh
set -e

LIBDIR=/usr/lib/${LIB_DIR}
STASH=${MESA_DIVERT_DIR}
PKG=${PKG_NAME}
FILES="${MESA_DIVERT_FILES}"

if [ "\$1" = "install" ] || [ "\$1" = "upgrade" ]; then
    mkdir -p "\$STASH"
    for f in \$FILES; do
        # 已经有同样的 diversion 就跳过(升级场景)
        if dpkg-divert --list "\$LIBDIR/\$f" 2>/dev/null | grep -q "to \$STASH/\$f by"; then
            continue
        fi
        # 真实路径上如果是 mesa 的实体，--rename 把它挪进 STASH 腾出位置；
        # 如果已经是指向 libMali.so 的软链(本包旧版本留下的)，就不要搬。
        if [ -e "\$LIBDIR/\$f" ] && [ "\$(readlink -f "\$LIBDIR/\$f")" != "\$LIBDIR/libMali.so" ]; then
            dpkg-divert --package "\$PKG" --divert "\$STASH/\$f" --rename --add "\$LIBDIR/\$f"
        else
            dpkg-divert --package "\$PKG" --divert "\$STASH/\$f" --no-rename --add "\$LIBDIR/\$f"
        fi
    done
fi

exit 0
EOF
    chmod 755 "${DEBIAN_DIR}/preinst"
}

# Create postrm script for Mali GPU libraries
# 卸载时撤销 diversion，把 mesa 的实体搬回原位
function _gpu_libgles_create_postrm() {
    display_alert "COMPILE-GPU Creating post-removal script DEBIAN/postrm" "info"
    cat > "${DEBIAN_DIR}/postrm" << EOF
#!/bin/sh
set -e

LIBDIR=/usr/lib/${LIB_DIR}
STASH=${MESA_DIVERT_DIR}
FILES="${MESA_DIVERT_FILES}"

if [ "\$1" = "remove" ] || [ "\$1" = "purge" ]; then
    for f in \$FILES; do
        if dpkg-divert --list "\$LIBDIR/\$f" 2>/dev/null | grep -q "to \$STASH/\$f by"; then
            # 真实路径必须先空出来，--rename 才能把 mesa 的文件搬回
            rm -f "\$LIBDIR/\$f"
            dpkg-divert --rename --remove "\$LIBDIR/\$f"
        fi
    done
    rmdir "\$STASH" 2>/dev/null || true
    ldconfig
fi

exit 0
EOF
    chmod 755 "${DEBIAN_DIR}/postrm"
}

# Create postinst script for Mali GPU libraries
function _gpu_libgles_create_postinst() {
    display_alert "COMPILE-GPU Creating post-installation script DEBIAN/postinst" "info"
    cat > "${DEBIAN_DIR}/postinst" << EOF
#!/bin/sh
set -e

if [ "\$1" = "configure" ]; then
    # Update ldconfig cache
    ldconfig

    # Set up Vulkan ICD
    if [ -d /usr/share/vulkan/icd.d ]; then
        echo "Vulkan ICD files installed"
    fi

    # Check firmware
    if [ ! -f /lib/firmware/mali_csffw.bin ]; then
        echo "Warning: Mali firmware not found at /lib/firmware/mali_csffw.bin" >&2
    fi

    if [ -f /usr/lib/${LIB_DIR}/libEGL.so.1.1.0 ]; then
        rm /usr/lib/${LIB_DIR}/libEGL.so.1.1.0
        echo "remove libEGL.so.1.1.0" >&2
    fi

    # Create symlinks if they don't exist
    if [ -f /usr/lib/${LIB_DIR}/libMali.so ]; then
        cd /usr/lib/${LIB_DIR}

        # Remove existing symlinks if they're broken
        for lib in libEGL.so libGLESv1_CM.so libGLESv2.so libgbm.so; do
            if [ -L "\${lib}" ] && [ ! -e "\${lib}" ]; then
                rm -f "\${lib}"
                echo "rm lib \${lib}"
            fi
        done

        # Create symlinks
        ln -sf libMali.so libEGL.so.1.4.0 2>/dev/null || true
        ln -sf libEGL.so.1.4.0 libEGL.so.1 2>/dev/null || true
        ln -sf libEGL.so.1 libEGL.so 2>/dev/null || true

        ln -sf libMali.so libGLESv1_CM.so.1.1.0 2>/dev/null || true
        ln -sf libGLESv1_CM.so.1.1.0 libGLESv1_CM.so.1 2>/dev/null || true
        ln -sf libGLESv1_CM.so.1 libGLESv1_CM.so 2>/dev/null || true

        ln -sf libMali.so libGLESv2.so.2.1.0 2>/dev/null || true
        ln -sf libGLESv2.so.2.1.0 libGLESv2.so.2 2>/dev/null || true
        ln -f -s libGLESv2.so.2 libGLESv2.so 2>/dev/null || true

        ln -sf libMali.so libgbm.so.1.0.0 2>/dev/null || true
        ln -sf libgbm.so.1.0.0 libgbm.so.1 2>/dev/null || true
        ln -sf libgbm.so.1 libgbm.so 2>/dev/null || true

        # Update ldconfig again
        ldconfig

        ls libEGL.so* -all
    fi
fi

exit 0
EOF
    chmod 755 "${DEBIAN_DIR}/postinst"
}

# Create prerm script for Mali GPU libraries
function _gpu_libgles_create_prerm() {
    display_alert "COMPILE-GPU Creating pre-removal script DEBIAN/prerm" "info"
    cat > "${DEBIAN_DIR}/prerm" << EOF
#!/bin/sh
set -e

if [ "\$1" = "remove" ] || [ "\$1" = "deconfigure" ]; then
    # Clean up symlinks
    for lib in libEGL.so libGLESv1_CM.so libGLESv2.so libgbm.so; do
        if [ -L /usr/lib/${LIB_DIR}/\${lib} ]; then
            # Only remove if it points to libMali.so
            if [ "$(readlink -f /usr/lib/${LIB_DIR}/\${lib})" = "/usr/lib/${LIB_DIR}/libMali.so" ]; then
                rm -f /usr/lib/${LIB_DIR}/\${lib}
            fi
        fi
    done

    # Update ldconfig
    ldconfig
fi

exit 0
EOF
    chmod 755 "${DEBIAN_DIR}/prerm"
}

# Create postinst script for kernel modules
function _gpu_kernel_create_postinst() {
    local kernel_version="$1"
    display_alert "COMPILE-GPU-DRIVER Creating post-installation script DEBIAN/postinst" "info"
    cat > "${DEBIAN_DIR}/postinst" << EOF
#!/bin/sh
set -e

if [ "\$1" = "configure" ]; then
    # Update module dependencies
    if [ -d "/lib/modules/${kernel_version}" ]; then
        depmod -a "${kernel_version}"
    else
        echo "Warning: /lib/modules/${kernel_version} not found, skipping depmod"
    fi

    # Check if module can be loaded
    if modprobe -n mali 2>/dev/null; then
        echo "GPU module can be loaded with 'modprobe mali'"
    fi
fi

exit 0
EOF
    chmod 755 "${DEBIAN_DIR}/postinst"
}

# Create prerm script for kernel modules
function _gpu_kernel_create_prerm() {
    display_alert "COMPILE-GPU-DRIVER Creating pre-removal script DEBIAN/prerm" "info"
    cat > "${DEBIAN_DIR}/prerm" << EOF
#!/bin/sh
set -e

if [ "\$1" = "remove" ] || [ "\$1" = "deconfigure" ]; then
    # Unload module if loaded
    if lsmod | grep -q "mali"; then
        modprobe -r mali 2>/dev/null || true
    fi
fi

exit 0
EOF
    chmod 755 "${DEBIAN_DIR}/prerm"
}

# ------------------------------------------------------------------------------
# Step 4: Source/Vendor File Copying
# ------------------------------------------------------------------------------

# Copy Mali GPU vendor binaries to install directory
function _gpu_libgles_copy_vendor_files() {
    display_alert "COMPILE-GPU Copying files from vendor binaries ${VENDOR_DIR}" "info"

    # Copy headers
    if [[ -d "${VENDOR_DIR}/include" ]]; then
        cp -r "${VENDOR_DIR}/include/"* "${INSTALL_DIR}/usr/include/"
        display_alert "COMPILE-GPU Copied headers EGL, GLES, GLES2, GLES3, KHR" "info"
    else
        display_alert "COMPILE-GPU Headers not found ${VENDOR_DIR}/include" "err"
    fi

    # Copy library
    if [[ -f "${VENDOR_DIR}/lib/${MALI_ARCH}/${GPU_MODE}/r54p1/wayland/drm/libMali_dmaheap.so" ]]; then
        cp "${VENDOR_DIR}/lib/${MALI_ARCH}/${GPU_MODE}/r54p1/wayland/drm/libMali_dmaheap.so" \
        "${INSTALL_DIR}/usr/lib/${LIB_DIR}/libMali.so"
        display_alert "COMPILE-GPU Copied main library libMali.so" "info"
    else
        # Try alternative path
        if [[ -f "${VENDOR_DIR}/lib/${MALI_ARCH}/${GPU_MODE}/r54p1/wayland/drm/libMali.so" ]]; then
            cp "${VENDOR_DIR}/lib/${MALI_ARCH}/${GPU_MODE}/r54p1/wayland/drm/libMali.so" "${INSTALL_DIR}/usr/lib/${LIB_DIR}/"
            display_alert "COMPILE-GPU Copied main library (alternative path) libMali.so" "info"
        else
            display_alert "COMPILE-GPU Main library not found libMali.so" "err"
            exit 1
        fi
    fi

    # Copy pkgconfig files
    if [[ -d "${VENDOR_DIR}/lib/pkgconfig" ]]; then
        cp -r "${VENDOR_DIR}/lib/pkgconfig/"* "${INSTALL_DIR}/usr/lib/pkgconfig/"
        display_alert "COMPILE-GPU Copied pkgconfig files *.pc" "info"
    fi

    # Copy Vulkan files
    if [[ -d "${VENDOR_DIR}/lib/${MALI_ARCH}/vulkan/r54p1/icd.d" ]]; then
        cp -r "${VENDOR_DIR}/lib/${MALI_ARCH}/vulkan/r54p1/icd.d/"* "${INSTALL_DIR}/usr/share/vulkan/icd.d"
        display_alert "COMPILE-GPU Copied Vulkan files ICD" "info"
    fi
    if [[ -d "${VENDOR_DIR}/lib/${MALI_ARCH}/vulkan/r54p1/implicit_layer.d" ]]; then
        cp -r "${VENDOR_DIR}/lib/${MALI_ARCH}/vulkan/r54p1/implicit_layer.d/"* "${INSTALL_DIR}/usr/share/vulkan/implicit_layer.d"
        display_alert "COMPILE-GPU Copied Vulkan files implicit layers" "info"
    fi

    # Copy firmware
    if [[ -f "${VENDOR_DIR}/lib/firmware/${GPU_MODE}/r54p1/mali_csffw.bin" ]]; then
        cp "${VENDOR_DIR}/lib/firmware/${GPU_MODE}/r54p1/mali_csffw.bin" "${INSTALL_DIR}/lib/firmware/"
        display_alert "COMPILE-GPU Copied firmware mali_csffw.bin" "info"
    else
        display_alert "COMPILE-GPU Firmware not found mali_csffw.bin" "err"
    fi

    # Copy configuration file
    if [[ -f "${VENDOR_DIR}/etc/aml_afrc_allowlist.config" ]]; then
        cp "${VENDOR_DIR}/etc/aml_afrc_allowlist.config" "${INSTALL_DIR}/etc/"
        display_alert "COMPILE-GPU Copied configuration file aml_afrc_allowlist.config" "info"
    elif [[ -f "${FILES_DIR}/aml_afrc_allowlist.config" ]]; then
        cp "${FILES_DIR}/aml_afrc_allowlist.config" "${INSTALL_DIR}/etc/"
        display_alert "COMPILE-GPU Copied configuration file from extension aml_afrc_allowlist.config" "info"
    fi
}

# ------------------------------------------------------------------------------
# Step 5: Symlink Creation (Mali GPU libraries only)
# ------------------------------------------------------------------------------

# Create Mali GPU library symlinks in the install directory
function _gpu_libgles_create_symlinks() {
    display_alert "COMPILE-GPU Creating symlinks in package libMali.so -> libEGL.so, etc." "info"
    cd "${INSTALL_DIR}/usr/lib/${LIB_DIR}"
    ln -sf libMali.so libEGL.so.1.4.0
    ln -sf libEGL.so.1.4.0 libEGL.so.1
    ln -sf libEGL.so.1 libEGL.so

    ln -sf libMali.so libGLESv1_CM.so.1.1.0
    ln -sf libGLESv1_CM.so.1.1.0 libGLESv1_CM.so.1
    ln -sf libGLESv1_CM.so.1 libGLESv1_CM.so

    ln -sf libMali.so libGLESv2.so.2.1.0
    ln -sf libGLESv2.so.2.1.0 libGLESv2.so.2
    ln -sf libGLESv2.so.2 libGLESv2.so

    ln -sf libMali.so libgbm.so.1.0.0
    ln -sf libgbm.so.1.0.0 libgbm.so.1
    ln -sf libgbm.so.1 libgbm.so
    cd - > /dev/null
}

# ------------------------------------------------------------------------------
# Step 6: Debian Package Building
# ------------------------------------------------------------------------------

# Build Debian package from install directory
# Parameters:
#   $1 - log prefix (e.g. "COMPILE-GPU" or "COMPILE-GPU-DRIVER")
#   $2 - output deb filename (without path)
# Sets: OUTPUT_DEB
function _gpu_build_deb_package() {
    local log_prefix="$1"
    local output_deb_name="$2"

    # 将install目录内容拷贝到deb目录
    display_alert "Copying install directory to deb package directory ${log_prefix}" "info"
    cp -r "${INSTALL_DIR}/"* "${DEB_PACKAGE_DIR}/" 2>&1

    # 基于deb目录打包
    display_alert "Building Debian package from deb directory ${log_prefix}" "info"
    dpkg-deb --build "${DEB_PACKAGE_DIR}" 2>&1

    # Move to output directory
    OUTPUT_DEB="${SRC}/output/${output_deb_name}"
    mkdir -p "$(dirname "${OUTPUT_DEB}")"
    mv "${DEB_PACKAGE_DIR}.deb" "${OUTPUT_DEB}"

    display_alert "${log_prefix} Package built successfully ${output_deb_name}" "info"
    display_alert "${log_prefix} Build directory preserved ${BASE_BUILD_DIR}" "info"
}

# Display build directory info
# Parameters:
#   $1 - log prefix
function _gpu_display_build_info() {
    local log_prefix="$1"
    display_alert "${log_prefix} Source dir: ${SOURCE_DIR}" "info"
    display_alert "${log_prefix} Build dir: ${BUILD_DIR}" "info"
    display_alert "${log_prefix} Install dir: ${INSTALL_DIR}" "info"
    display_alert "${log_prefix} Patch dir: ${PATCH_DIR}" "info"
    display_alert "${log_prefix} Deb package dir: ${DEB_PACKAGE_DIR}" "info"
}

# ==============================================================================
# Main Build Functions (Entry Points - DO NOT RENAME)
# ==============================================================================

# ------------------------------------------------------------------------------
# Mali GPU Library Build (libgles)
# Entry point: amlbian_build_libgles
# ------------------------------------------------------------------------------

function amlbian_build_libgles() {

    # ---- Step 1: Version and Package Information ----
    _gpu_libgles_init_package_info

    # amlbian_checkout_toolchain

    # ---- Step 2: Build Directory Setup ----
    _gpu_create_build_dirs "${PKG_NAME}_${PKG_VERSION}_${PKG_ARCH}"
    _gpu_libgles_create_install_dirs

    # Display info
    display_alert "COMPILE-GPU Building GLES driver package version ${PKG_VERSION} for ${PKG_ARCH}" "info"
    _gpu_display_build_info "COMPILE-GPU"

    # ---- Step 3: Debian Packaging Scripts ----
    _gpu_create_control_file \
        "${PKG_NAME}" "${PKG_VERSION}" "${PKG_ARCH}" "${PKG_MAINTAINER}" \
        "${PKG_DESCRIPTION}" \
        "libdrm2, libwayland-client0, libwayland-server0, libwayland-egl1" \
        "libmali-valhall-g610-g6p0, libmali-bifrost-g31-g13p0" \
        "libegl1, libgles1, libgles2, libgbm1" \
        "libs" \
        "libgbm1, libgbm-dev, libegl1, libegl-dev, libgles1, libgles2, libgles-dev"

    _gpu_libgles_create_preinst
    _gpu_libgles_create_postinst
    _gpu_libgles_create_prerm
    _gpu_libgles_create_postrm

    # ---- Step 4: Copy Source/Vendor Files ----
    _gpu_libgles_copy_vendor_files

    # ---- Step 5: Create Symlinks ----
    _gpu_libgles_create_symlinks

    # Remove wayland-egl files (as per original recipe)
    display_alert "COMPILE-GPU Removing wayland-egl files as per original recipe" "info"
    rm -f "${INSTALL_DIR}/usr/lib/${LIB_DIR}/libwayland-egl"* 2>/dev/null || true
    find "${INSTALL_DIR}/usr/lib/pkgconfig" -name "wayland-egl.pc" -delete 2>/dev/null || true

    # ---- Step 6: Build Debian Package ----
    _gpu_build_deb_package "COMPILE-GPU" "${PKG_NAME}_${PKG_VERSION}_${PKG_ARCH}.deb"

    return 0
}

# ------------------------------------------------------------------------------
# GPU Kernel Module Build
# ------------------------------------------------------------------------------

# ------------------------------------------------------------------------------
# Shared helper: Build kernel modules in a temp directory
# Parameters:
#   $1 - kernel build directory
#   $2 - driver source path
#   $3 - include path
#   $4 - build output directory
#   $5 - extra cflags
# Outputs: sets MALI_KO_SRC, PMA_KO_SRC
# ------------------------------------------------------------------------------
function _gpu_build_kernel_modules() {
    local kernel_build_dir="$1"
    local drv_src="$2"
    local inc_dir="$3"
    local build_out_dir="$4"
    local extra_cflags="$5"

    local module_build_dir="${build_out_dir}/module_build"
    mkdir -p "${module_build_dir}"

    display_alert "COMPILE-GPU-DRIVER Copying source files to build directory to avoid pollution" "info"
    cp -r "${drv_src}" "${module_build_dir}/"
    cp -r "${inc_dir}" "${module_build_dir}/"

    local build_drv_src="${module_build_dir}/drivers"
    local build_inc_dir="${module_build_dir}/include"

    display_alert "COMPILE-GPU-DRIVER Building GPU kernel modules in build directory kernel_build_dir ${kernel_build_dir} build_drv_src ${build_drv_src} extra_cflags ${extra_cflags} build_inc_dir ${build_inc_dir}" "info"
    make -C "${kernel_build_dir}" M="${build_drv_src}" \
        EXTRA_CFLAGS="${extra_cflags} -I${build_inc_dir}" \
        CONFIG_MALI_MIDGARD=m \
        CONFIG_MALI_DEVFREQ=y \
        ARCH=arm64 \
        CROSS_COMPILE=${CROSS_COMPILE:-aarch64-linux-gnu-} \
        CONFIG_MALI_GATOR_SUPPORT=y \
        CONFIG_MALI_REAL_HW=y \
        CONFIG_MALI_CSF_SUPPORT=y \
        CONFIG_MALI_PROTECTED_MEMORY_ALLOCATOR=y \
        CONFIG_MALI_PLATFORM_NAME="devicetree" \
        modules

    MALI_KO_SRC="${build_drv_src}/gpu/arm/midgard/mali_kbase.ko"
    PMA_KO_SRC="${build_drv_src}/base/arm/protected_memory_allocator/protected_memory_allocator.ko"

    if [[ ! -f "${MALI_KO_SRC}" || ! -f "${PMA_KO_SRC}" ]]; then
        display_alert "COMPILE-GPU-DRIVER Module build failed. Missing .ko files" "error"
        exit 1
    fi

    display_alert "COMPILE-GPU-DRIVER" "Modules build successfully" "info"

    # Return the module build dir for cleanup
    echo "${module_build_dir}"
}

# ------------------------------------------------------------------------------
# Shared helper: Install kernel modules to install directory
# Parameters:
#   $1 - module directory under INSTALL_DIR
#   $2 - mali.ko source path
#   $3 - protected_memory_allocator.ko source path
# ------------------------------------------------------------------------------
function _gpu_install_kernel_modules() {
    local module_dir="$1"
    local mali_ko_src="$2"
    local pma_ko_src="$3"

    display_alert "COMPILE-GPU-DRIVER Installing modules to ${module_dir}" "info"
    install -m 0644 "${mali_ko_src}" "${module_dir}/mali.ko"
    install -m 0644 "${pma_ko_src}" "${module_dir}/protected_memory_allocator.ko"
}

# ------------------------------------------------------------------------------
# GPU Kernel Module Build
# Entry point: amlbian_build_gpu_driver
# ------------------------------------------------------------------------------

function amlbian_build_gpu_driver() {
    set -e

    # ---- Step 1: Version and Package Information ----
    _gpu_kernel_init_package_info
    # amlbian_checkout_toolchain

    # Source directories
    local gpu_src_dir="${BASE_DIR}/aml-comp/hardware/arm/gpu/${GPU_ARCH}/${DIR_VERSION}/kernel"
    local gpu_drv_src="${gpu_src_dir}/drivers"
    local gpu_inc_dir="${gpu_src_dir}/include"

    if [[ ! -d "${gpu_drv_src}" || ! -d "${gpu_inc_dir}" ]]; then
        display_alert "COMPILE-GPU-DRIVER GPU source code not found. Expected at: ${gpu_src_dir}" "error"
        exit 1
    fi

    local kernel_version
    kernel_version=$(make -s -C "${BASE_DIR}/aml-comp/kernel/aml-6.12/build" kernelrelease 2>/dev/null || true)
    kernel_version="${kernel_version:-unknown-$(date +%Y%m%d)}"

    display_alert "COMPILE-GPU-DRIVER Building GPU kernel modules version ${PKG_VERSION} for ${PKG_ARCH}" "info"
    display_alert "COMPILE-GPU-DRIVER Building for kernel version ${kernel_version}" "info"

    # ---- Step 2: Build Directory Setup ----
    _gpu_create_build_dirs "${PKG_NAME}_${PKG_VERSION}_${PKG_ARCH}"
    local module_dir="${INSTALL_DIR}/lib/modules/${kernel_version}/kernel/drivers/arm/gpu"
    mkdir -p "${module_dir}"
    _gpu_display_build_info "COMPILE-GPU-DRIVER"

    # Copy source to source directory
    display_alert "COMPILE-GPU-DRIVER Copying source files to source directory" "info"
    cp -r "${gpu_drv_src}" "${SOURCE_DIR}/drivers"
    cp -r "${gpu_inc_dir}" "${SOURCE_DIR}/include"

    local kernel_build_dir="${BASE_DIR}/aml-comp/kernel/aml-6.12/build"
    display_alert "COMPILE-GPU-DRIVER kernel_build_dir ${kernel_build_dir}" "info"

    # ---- Step 3: Debian Packaging Scripts ----
    _gpu_create_control_file \
        "${PKG_NAME}" "${PKG_VERSION}" "${PKG_ARCH}" "${PKG_MAINTAINER}" \
        "${PKG_DESCRIPTION}" "" "" "" "kernel"

    _gpu_kernel_create_postinst "${kernel_version}"
    _gpu_kernel_create_prerm

    # ---- Step 4: Build Kernel Modules ----
    local extra_cflags="-DCONFIG_MALI_DEVFREQ -DCONFIG_MALI_GATOR_SUPPORT -DCONFIG_MALI_CSF_SUPPORT -DCONFIG_MALI_REAL_HW"
    extra_cflags="${extra_cflags} -I${gpu_inc_dir} -DCONFIG_MALI_LOW_MEM=${GPU_LOW_MEM}"

    local module_build_dir
    module_build_dir=$(_gpu_build_kernel_modules \
        "${kernel_build_dir}" "${gpu_drv_src}" "${gpu_inc_dir}" \
        "${BUILD_DIR}" "${extra_cflags}")

    MALI_KO_SRC="${BUILD_DIR}/module_build/drivers/gpu/arm/midgard/mali_kbase.ko"
    PMA_KO_SRC="${BUILD_DIR}/module_build/drivers/base/arm/protected_memory_allocator/protected_memory_allocator.ko"

    display_alert "COMPILE-GPU-DRIVER MALI_KO_SRC ${MALI_KO_SRC} PMA_KO_SRC ${PMA_KO_SRC}" "info"
    _gpu_install_kernel_modules "${module_dir}" "${MALI_KO_SRC}" "${PMA_KO_SRC}"

    # Clean up temporary build directory
    rm -rf "${BUILD_DIR}/module_build"

    # ---- Step 5: Build Debian Package ----
    _gpu_build_deb_package "COMPILE-GPU-DRIVER" "${PKG_NAME}_${PKG_VERSION}_${kernel_version}_${PKG_ARCH}.deb"

    display_alert "COMPILE-GPU-DRIVER GPU modules build completed. Successfully built for ${PKG_ARCH} with kernel ${kernel_version}" "info"
    return 0
}

function amlbian_build_gpu() {
    if ! is_unit_enabled "gpu"; then
        echo "[SKIP] >> Gpu disable in BUILD_UNITS"
        return
    fi
    amlbian_build_libgles
    amlbian_build_gpu_driver
}

display_alert "AMLbian gpu Build Script" "Version: ${KERNEL_VERSION}  GPU_MODE : ${GPU_MODE}, GPU_ARCH: ${GPU_ARCH}, Board: ${BOARD}" "info"
amlbian_build_gpu
display_alert "AMLOGIC: gpu build completed" "${OUTPUT_DIR}" "info"