#!/bin/bash
set -e

LINUX_DIR="${1:-linux-adi}"
DTFILE="$2"
CROSS_COMPILE="$3"
BRANCH="${4:-rpi-5.4.y}"

HOST=${HOST:-x86_64}

DEFCONFIG=${DEFCONFIG:-adi_bcm2709_defconfig}
GCC_ARCH=arm-linux-gnueabihf
IMG_NAME="zImage"
ARCH=arm

[ -n "$NUM_JOBS" ] || NUM_JOBS=5

# if CROSS_COMPILE hasn't been specified, go with a few defaults
[ -n "$CROSS_COMPILE" ] || {
	CROSS_COMPILE=${GCC_ARCH}-gcc
	if type "${GCC_ARCH}-gcc" >/dev/null 2>&1 ; then
		CROSS_COMPILE="${GCC_ARCH}-"
	else
		GCC_VERSION="8.3-2019.03"
		GCC_DIR="gcc-arm-${GCC_VERSION}-${HOST}-${GCC_ARCH}"
		GCC_TAR="$GCC_DIR.tar.xz"
		GCC_URL="https://developer.arm.com/-/media/Files/downloads/gnu-a/${GCC_VERSION}/binrel/${GCC_TAR}"
		if [ ! -d "$GCC_DIR" ] && [ ! -e "$GCC_TAR" ] ; then
			wget "$GCC_URL"
		fi
		if [ ! -d "$GCC_DIR" ] ; then
			tar -xvf $GCC_TAR || {
				echo "'$GCC_TAR' seems invalid ; remove it and re-download it"
				exit 1
			}
		fi
		CROSS_COMPILE=$(pwd)/$GCC_DIR/bin/${GCC_ARCH}-
	fi
}

# FIXME: remove the line below once Talise & Mykonos APIs
#        dont't use 1024 bytes on stack
KCFLAGS="$KCFLAGS -Wno-error=frame-larger-than="
export KCFLAGS

# FIXME: remove this function once kernel gets upgrade and
#        GCC doesn't report these warnings anymore
GCC="${CROSS_COMPILE}gcc"
if [ "$($GCC -dumpversion | cut -d. -f1)" -ge "8" ]; then
	KCFLAGS="$KCFLAGS -Wno-error=stringop-truncation"
	KCFLAGS="$KCFLAGS -Wno-error=packed-not-aligned"
	KCFLAGS="$KCFLAGS -Wno-error=stringop-overflow= -Wno-error=sizeof-pointer-memaccess"
	KCFLAGS="$KCFLAGS -Wno-error=missing-attributes"
fi

if [ "$($GCC -dumpversion | cut -d. -f1)" -ge "9" ]; then
	KCFLAGS="$KCFLAGS -Wno-error=address-of-packed-member -Wno-error=stringop-truncation"
fi
export KCFLAGS

# Get ADI Linux if not downloaded
# We won't do any `git pull` to update the tree, users can choose to do that manually
[ -d "$LINUX_DIR" ] || {
	git clone https://github.com/analogdevicesinc/linux.git "$LINUX_DIR"
	pushd $LINUX_DIR
	git checkout "$BRANCH"
	popd 1> /dev/null
}

export ARCH
export CROSS_COMPILE

pushd "$LINUX_DIR"

make $DEFCONFIG

make -j$NUM_JOBS

popd 1> /dev/null

cp -f $LINUX_DIR/arch/$ARCH/boot/$IMG_NAME .

echo "Exported files: $IMG_NAME"