#!/bin/bash
set -e

#
# just the minimum: stock + XEN + UFS
# reiser4 patch optional
# need to grab config first
#

[[ -z $2 ]] && echo "usage: ${0##*/} <kernel folder> <base config> [patch.gz]" && exit 1
linux=$1
baseconfig=$2
patch=$3

[[ ! -d $linux ]] && echo cannot find folder $linux && exit 1

[[ ! -f $baseconfig ]] && echo cannot find file $baseconfig && exit 1

[[ -n $patch && ! -f $patch ]] && echo cannot find file $patch && exit 1

#[[ ! -x `which lscpu` ]] && echo missing lspcu && exit 1
#cpu=$((`grep ^processor /proc/cpuinfo | tail -1 | awk '{print $3}'` + 1))
#echo cpu is $cpu
#lscpu | grep Thread
# TODO take threads into account
#export MAKEFLAGS=-j$cpu

[[ -z $MAKEFLAGS ]] && echo MAKEFLAGS not defined && exit 1
echo MAKEFLAGS is $MAKEFLAGS

cp -fv $baseconfig $linux/.config

cd $linux/

echo CONFIG
#mirror=`grep -vE '^#|^$' /etc/slackpkg/mirrors`
#echo mirror is $mirror
#echo ready?
#read -r
#wget -q -O - $mirror/kernels/VERSIONS.TXT
#wget -qO - $mirror/kernels/huge.s/config > .config
make olddefconfig >/dev/null && echo DONE
echo

if [[ -n $patch ]]; then
	echo PATCH FOR REISER4
	zcat ../$patch | patch -p1 > ../build0.log && echo DONE
	echo

	echo REISER4 CONFIG
	cat >> .config <<-EOF
	CONFIG_REISER4_FS=y
	EOF
	make olddefconfig >/dev/null
	grep REISER4_FS .config
	echo
fi

echo XEN CONFIG
make xen.config >/dev/null
make olddefconfig >/dev/null && echo DONE
echo

echo UFS WRITE
cat >> .config <<EOF
CONFIG_UFS_FS=y
CONFIG_UFS_FS_WRITE=y
EOF
make olddefconfig >/dev/null && echo DONE
echo

# warning: override: reassigning to symbol X86_X32
# https://forums.gentoo.org/viewtopic-p-8686301.html?sid=0bbd138e7fedcec48fe7d6c5e06abbd6
echo DISABLE X86_X32
echo CONFIG_X86_X32=n >> .config
make olddefconfig >/dev/null && echo DONE
echo

echo BUILD KERNEL
echo tail -F /usr/src/build0.log
time nice make >> ../build0.log && echo DONE
echo

echo DEPLOY MODULES
nice make modules_install >> ../build0.log && echo DONE
echo

file arch/x86/boot/bzImage
ver=`file arch/x86/boot/bzImage | awk '{print $9}'`

cat <<EOF

you're good to go locally

	cp -nv $linux/arch/x86/boot/bzImage /vmlinuz
	cp -nv $linux/.config /vmlinuz.config
	ls -lF /lib/modules/
	depmod -a $ver
	shutdown -r now

and eventually prepare additional third-party modules e.g. drbd and zfs