已經成功像一般的distro 可以從 iso file boot 了
其中第2部份必須改寫
又將共同的功能寫成function 放在最前面 成為第0部份
而第1部份參數有重新命名
從 iso file boot 是目前最複雜的使用情況
主要動作有 1. 掛載iso
2. 掛載iso 裡面的loopfile 到 lower
3. 掛載另一個可寫的device ( tmpfs, loopfile 或 block device), 給 upper 和 work
4. mount 好整個 OverlayFS 然後boot.
完全參數化 會有10多個參數 如此才夠應付多數情況
以下為 initrd.d/linuxrc的新增4部份
=====================================
# zm 0
# $1: device name
# $2: mount point (full path)
# $3: caller's var for storing the results
is_mounted() {
local _FOUND
eval _FOUND='$( [ -n "$( mount | grep "${1} on ${2} " )" ] && echo '1' || echo '0' )'
if [ -n "${3}" ]; then
eval $"${3}"='"$_FOUND"'
else
echo "$_FOUND" # > /dev/null
fi
}
# $1: device name
# $2: mount point
# $3: options
mount_device() {
if [ -e "${1}" -a -d "${2}" ] && [ "$( is_mounted "${1}" "${2}" )" -eq '0' ]; then
if [ -n "${3}" ]; then
echo mount -o "${3}" "${1}" "${2}"
mount -o "${3}" "${1}" "${2}"
else
echo mount "${1}" "${2}"
mount "${1}" "${2}"
fi
fi
}
# $1: file name
# $2: mount point
# $3: options
mount_loopfile() {
if [ -f "${1}" -a -d "${2}" ]; then
local DEV=$( losetup -f ) # local DEV=`losetup -f`
echo losetup "$DEV" "${1}"
losetup "$DEV" "${1}"
if [ -n "${3}" ]; then
echo mount -o "${3}" "$DEV" "${2}"
mount -o "${3}" "$DEV" "${2}"
else
echo mount "$DEV" "${2}"
mount "$DEV" "${2}"
fi
fi
}
# $1: name
real_device() {
local DEVICE="${1}"
case "${DEVICE}" in
UUID\=*|LABEL\=*)
local REAL_DEVICE=""
local retval=1
if [ "${retval}" -ne 0 ]; then
REAL_DEVICE=$( findfs "${DEVICE}" 2>/dev/null)
retval=$?
fi
if [ "$retval" -ne 0 ]; then
REAL_DEVICE=$( busybox findfs "${DEVICE}" 2>/dev/null)
retval=$?
fi
if [ "${retval}" -ne 0 ]; then
REAL_DEVICE=$( blkid -o device -l -t "${DEVICE}")
retval=$?
fi
if [ "${retval}" -eq 0 ] && [ -n "${REAL_DEVICE}" ]; then
DEVICE="${REAL_DEVICE}"
fi
;;
esac
echo -n "${DEVICE}"
}
# $1: dev name
# $2: mount point
# $3: loopfile
# $4: loopfile mount point
# $5: loopfile mount options
setup_loop_device() {
REAL_LOOPS_DEV=$( real_device "${1}" )
# echo mount_device "$REAL_LOOPS_DEV" "${2}"
mount_device "$REAL_LOOPS_DEV" "${2}"
local DEV=$( losetup -f) # local DEV=`losetup -f`
if [ -e "${3}" ]; then
echo losetup "$DEV" "${3}"
losetup "$DEV" "${3}"
if [ -n "${4}" ]; then
mkdir -p "${4}"
# echo mount_device "$DEV" "${4}" "${5}"
mount_device "$DEV" "${4}" "${5}"
fi
fi
}
# $1: lower dir
# $2: upper dir
# $3: work dir
# $4: merged dir
setup_overlay_fs() {
mount -t overlay -o lowerdir="${1}",upperdir="${2}",workdir="${3}" overlay "${4}"
}
# zm
======================================
# zm 1: get parameters for boot from loop file or overlayfs
loops_dev=*)
LOOPS_DEV=${x#*=}
;;
loops_dev_mnt=*)
LOOPS_DEV_MNT=${x#*=}
;;
loop_file=*)
LOOP_FILE=${x#*=}
;;
loop_file_mnt=*)
LOOP_FILE_MNT=${x#*=}
;;
loop_file_mnt_opt=*)
LOOP_FILE_MNT_OPT=${x#*=}
;;
ovl_dev0=*)
OVL_DEV0=${x#*=}
;;
ovl_mnt0=*)
OVL_MNT0=${x#*=}
;;
ovl_loopfile0=*)
OVL_LOOPFILE0=${x#*=}
;;
ovl_mnt0_sub=*)
OVL_MNT0_SUB=${x#*=}
;;
ovl_dev1=*)
OVL_DEV1=${x#*=}
;;
ovl_mnt1=*)
OVL_MNT1=${x#*=}
;;
ovl_mnt1_opt=*)
OVL_MNT1_OPT=${x#*=}
;;
ovl_loopfile1=*)
OVL_LOOPFILE1=${x#*=}
;;
ovl_mnt1_sub=*)
OVL_MNT1_SUB=${x#*=}
;;
mount_move)
MOUNT_MOVE=1
;; # zm
================================================
# zm 2: find the device which contains loop files, mount and losetup.
if [ -n "${LOOPS_DEV}" ]; then
if [ -z "${LOOPS_DEV_MNT}" ]; then
LOOPS_DEV_MNT='/loops'
fi
mkdir -p $LOOPS_DEV_MNT
good_msg setup_loop_device "${LOOPS_DEV}" "${LOOPS_DEV_MNT}" "${LOOP_FILE}" "${LOOP_FILE_MNT}" "${LOOP_FILE_MNT_OPT}"
setup_loop_device "${LOOPS_DEV}" "${LOOPS_DEV_MNT}" "${LOOP_FILE}" "${LOOP_FILE_MNT}" "${LOOP_FILE_MNT_OPT}"
fi
# zm 2-1: find the devices, loopfiles, dirs for overlay fs.
if [ "${ROOTFSTYPE}" = 'overlay' ]; then
OVL_MNT_DEV0=""
if [ -n "${OVL_DEV0}" ]; then
OVL_MNT_DEV0=$( real_device "${OVL_DEV0}" )
fi
if [ -n "${OVL_MNT_DEV0}" ] && [ -n "${OVL_MNT0}" ]; then
mkdir -p ${OVL_MNT0}
good_msg mount_device
echo "${OVL_MNT_DEV0}" "${OVL_MNT0}"
mount_device "${OVL_MNT_DEV0}" "${OVL_MNT0}"
if [ "$?" = '0' ]; then
OVL_DEV0_MOUNTED=1
else
OVL_DEV0_MOUNTED=0
fi
fi
if [ "${OVL_DEV0_MOUNTED}" = '1' ]; then
if [ -n "${OVL_LOOPFILE0}" ]; then
if [ -z "${OVL_MNT0_SUB}" ]; then
OVL_MNT0_SUB="/lower"
fi
mkdir -p "${OVL_MNT0_SUB}"
good_msg mount_loopfile
echo "${OVL_LOOPFILE0}" "${OVL_MNT0_SUB}"
mount_loopfile "${OVL_LOOPFILE0}" "${OVL_MNT0_SUB}"
LOWER="${OVL_MNT0_SUB}"
else
if [ -n "${OVL_MNT0_SUB}" ]; then
LOWER="${OVL_MNT0_SUB}"
else
LOWER="${OVL_MNT0}"
fi
fi
fi
if [ -n "${OVL_DEV1}" ]; then
if [ "${OVL_DEV1}" = 'tmpfs' ]; then
if [ -z "${OVL_MNT1_OPT}" ]; then
OVL_MNT1_OPT='size=3072m'
fi
mkdir -p "${OVL_MNT1}"
good_msg "mount -t tmpfs -o ${OVL_MNT1_OPT} ${OVL_DEV1} ${OVL_MNT1}"
mount -t tmpfs -o "${OVL_MNT1_OPT}" "${OVL_DEV1}" "${OVL_MNT1}"
UPPER="${OVL_MNT1}/upper"
mkdir -p "${OVL_MNT1}/upper"
WORK="${OVL_MNT1}/work"
mkdir -p "${OVL_MNT1}/work"
else # [ "${OVL_DEV1}" = 'tmpfs' ]
OVL_MNT_DEV1=""
if [ -n "${OVL_DEV1}" ]; then
OVL_MNT_DEV1=$( real_device "${OVL_DEV1}" )
fi
if [ -n "${OVL_MNT_DEV1}" ] && [ -n "${OVL_MNT1}" ]; then
mkdir -p ${OVL_MNT1}
echo mount ${OVL_MNT_DEV1} ${OVL_MNT1}
mount ${OVL_MNT_DEV1} ${OVL_MNT1}
if [ -z "${OVL_LOOPFILE1}" ]; then
UPPER="${OVL_MNT1}/upper"
mkdir -p "${OVL_MNT1}/upper"
WORK="${OVL_MNT1}/work"
mkdir -p "${OVL_MNT1}/work"
fi
fi
if [ -n "${OVL_LOOPFILE1}" ]; then
if [ -z "${OVL_MNT1_SUB}" ]; then
OVL_MNT1_SUB="${OVL_MNT1}/rw"
fi
mkdir -p "${OVL_MNT1_SUB}"
good_msg mount_loopfile
echo "${OVL_LOOPFILE1}" "${OVL_MNT1_SUB}"
mount_loopfile "${OVL_LOOPFILE1}" "${OVL_MNT1_SUB}"
mkdir -p "${OVL_MNT1_SUB}/upper"
mkdir -p "${OVL_MNT1_SUB}/work"
UPPER="${OVL_MNT1_SUB}/upper"
WORK="${OVL_MNT1_SUB}/work"
else
if [ -n "${OVL_MNT1_SUB}" ]; then
mkdir -p "${OVL_MNT1_SUB}/upper"
mkdir -p "${OVL_MNT1_SUB}/work"
UPPER="${OVL_MNT1_SUB}/upper"
WORK="${OVL_MNT1_SUB}/work"
fi
fi
fi # [ "${OVL_DEV1}" = 'tmpfs' ]
else # [ -n "${OVL_DEV1}" ]
if [ -n "${OVL_LOOPFILE1}" ]; then
if [ -z "${OVL_MNT1_SUB}" ]; then
OVL_MNT1_SUB="${OVL_MNT0}/rw"
fi
mkdir -p "${OVL_MNT1_SUB}"
good_msg mount_loopfile
echo "${OVL_LOOPFILE1}" "${OVL_MNT1_SUB}"
mount_loopfile "${OVL_LOOPFILE1}" "${OVL_MNT1_SUB}"
mkdir -p "${OVL_MNT1_SUB}/upper"
mkdir -p "${OVL_MNT1_SUB}/work"
UPPER="${OVL_MNT1_SUB}/upper"
WORK="${OVL_MNT1_SUB}/work"
else #[ -n "${OVL_LOOPFILE1}" ]
if [ -n "${OVL_MNT1_SUB}" ]; then
mkdir -p "${OVL_MNT1_SUB}/upper"
mkdir -p "${OVL_MNT1_SUB}/work"
UPPER="${OVL_MNT1_SUB}/upper"
WORK="${OVL_MNT1_SUB}/work"
else
if [ -z "${UPPER}" ]; then
UPPER="${OVL_MNT0}/upper"
mkdir -p "${OVL_MNT0}/upper"
fi
if [ -z "${WORK}" ]; then
WORK="${OVL_MNT0}/work"
mkdir -p "${OVL_MNT0}/work"
fi
fi #[ -n "${OVL_MNT1_SUB}" ]
fi #[ -n "${OVL_LOOPFILE1}" ]
fi # [ -n "${OVL_DEV1}" ]
good_msg "OverlayFS: lowerdir=${LOWER},upperdir=${UPPER},workdir=${WORK} ..."
REAL_ROOTFLAGS="lowerdir=${LOWER},upperdir=${UPPER},workdir=${WORK}"
got_good_root=1
fi # zm [ "${ROOTFSTYPE}" = 'overlay' ]
=========================================================
# zm 3: move LOOPS_DEV_MNT or OVL_MNTs from initramfs to real root
if [ "${MOUNT_MOVE}" = '1' ]; then
if [ -n "${LOOPS_DEV_MNT}" ]; then
if [ ! -e "${CHROOT}${LOOPS_DEV_MNT}" ]; then
mkdir -p "${CHROOT}${LOOPS_DEV_MNT}"
fi
good_msg "Remounting device=${LOOPS_DEV} to ${CHROOT}${LOOPS_DEV_MNT}"
mount