|  |  | 
 |  |  |  | 
 |  |  | function build_kernel() | 
 |  |  | { | 
 |  |  |     PATCH_FILE=$PRJ_PATH/patches/$BOARD/linux-imx-$BSP_VER.patch | 
 |  |  |     defconfig=${BOARD}_defconfig | 
 |  |  |     patch_file=$PRJ_PATH/patches/$BOARD/linux-imx-$BSP_VER.patch | 
 |  |  |  | 
 |  |  |     cd $PRJ_PATH | 
 |  |  |  | 
 |  |  | 
 |  |  |     else | 
 |  |  |         pr_info "start fetch linux kernel source code" | 
 |  |  |         git clone $GIT_URL/linux-imx.git -b $BRANCH --depth=1 | 
 |  |  |  | 
 |  |  |         if [ -s $PATCH_FILE ] ; then | 
 |  |  |             pr_warn "do patch for $KER_PATH now..." | 
 |  |  |             cd $KER_PATH | 
 |  |  |             patch -p1 < $PATCH_FILE | 
 |  |  |         fi | 
 |  |  |     fi | 
 |  |  |  | 
 |  |  |     pr_info "Start build linux kernel source code" | 
 |  |  |  | 
 |  |  |     cd $KER_PATH | 
 |  |  |  | 
 |  |  |     defconfig=${BOARD}_defconfig | 
 |  |  |     if [ ! -s arch/arm64/configs/$defconfig ] ; then | 
 |  |  |         pr_warn "do patch for $KER_PATH now..." | 
 |  |  |         patch -p1 < $patch_file | 
 |  |  |     fi | 
 |  |  |  | 
 |  |  |     if [ ! -s .config ] ; then | 
 |  |  |         make ${defconfig} | 
 |  |  |     fi |