Use proper ${KERNEL_CONFIG} rather than ${KERNEL_DIR}/.config as input

gen_initramfs.sh

@@ -754,6 +754,13 @@ create_initramfs() {
 	else
 		if isTrue "${COMPRESS_INITRD}"
 		then
+			if [[ "$(file --brief --mime-type "${KERNEL_CONFIG}")" == application/x-gzip ]]; then
+				# Support --kernel-config=/proc/config.gz, mainly
+				local CONFGREP=zgrep
+			else
+				local CONFGREP=grep
+			fi
+
 			cmd_xz=$(type -p xz)
 			cmd_lzma=$(type -p lzma)
 			cmd_bzip2=$(type -p bzip2)
@@ -778,7 +785,7 @@ create_initramfs() {
 						set -- ${tuple}
 						kernel_option=$1
 						cmd_variable_name=$2
-						if grep -sq "^${kernel_option}=y" ${KERNEL_DIR}/.config && test -n "${!cmd_variable_name}" ; then
+						if ${CONFGREP} -q "^${kernel_option}=y" "${KERNEL_CONFIG}" && test -n "${!cmd_variable_name}" ; then
 							compression=$3
 							[[ ${COMPRESS_INITRD_TYPE} == best ]] && break
 						fi

genkernel

@@ -352,10 +352,20 @@ then
 	[ "${ZFS}" = '1' ] && print_warning 1 'add "dozfs" for ZFS volume management support'
 	[ "${ZFS}" = '1' ] && print_warning 1 'add either "real_root=ZFS" (bootfs autodetection) or "real_root=ZFS=<dataset>" to boot from a ZFS dataset'
 	[ "${ISCSI}" = '1' ] && print_warning 1 'add at least "iscsi_initiatorname=<initiator name> iscsi_target=<target name> and iscsi_address=<target ip>" for iscsi support'
-	if [ `grep 'CONFIG_EXT[0-9]_FS=' "${KERNEL_DIR}"/.config | wc -l` -ge 2 ]; then
+
+	if [[ "$(file --brief --mime-type "${KERNEL_CONFIG}")" == application/x-gzip ]]; then
+		# Support --kernel-config=/proc/config.gz, mainly
+		CONFGREP=zgrep
+	else
+		CONFGREP=grep
+	fi
+
+	if [ `${CONFGREP} 'CONFIG_EXT[0-9]_FS=' "${KERNEL_CONFIG}" | wc -l` -ge 2 ]; then
 		print_warning 1 'With support for several ext* filesystems around it may be needed to'
 		print_warning 1 'add "rootfstype=ext3" or "rootfstype=ext4"'
 	fi
+
+	unset CONFGREP
 fi
 
 [ "${BOOTRW}" != '' ] && mount -o remount,ro ${BOOTDIR}