openwrt: sysupgrade
sysupgrade
用法:
sysupgrade [<升级选项>...] <image file 或 URL>
sysupgrade [-q] [-i] <备份选项>
升级选项:
- -d
重启前等待 delay 秒 - -f
从 .tar.gz (文件或链接) 中恢复配置文件 - -i 交互模式
- -c 保留 /etc 中所有修改过的文件
- -n 重刷固件时不保留配置文件
- -T | --test 校验固件 config .tar.gz,但不真正烧写
- -F | --force 即使固件校验失败也强制烧写
- -q 较少的输出信息
- -v 详细的输出信息
- -h 显示帮助信息
备份选项:
- -b | --create-backup
把sysupgrade.conf 里描述的文件打包成.tar.gz 作为备份,不做烧写动作 - -r | --restore-backup
从-b 命令创建的 .tar.gz 文件里恢复配置,不做烧写动作 - -l | --list-backup
列出 -b 命令将备份的文件列表,但不创建备份文件
举例
-
更新openwrt.bin固件
sysupgrade openwrt.bin
-
强制更新openwrt.bin固件
sysupgrade会检查支持板子的固件头信息,如果一个model没有在sysupgrade的支持列表里,使用-F来忽略检查失败,强制烧写。
sysupgrade -F openwrt.bin
-
更新后不保存之前的配置
sysupgrade烧写时默认会备份配置文件,在烧写后把配置文件覆盖到新系统中。-n参数指定不做这个动作。
sysupgrade -n openwrt.bin
-
备份配置文件到/tmp/backup.tgz
sysupgrade -b /tmp/backup.tgz
-
恢复之前备份的/tmp/backup.tgz
sysupgrade -r /tmp/backup.tgz
-
列出会被备份的文件
sysupgrade -l
列出的文件会在-b备份时或系统升级时被保存。
实现
解析选项参数
# parse options
while [ -n "$1" ]; do
case "$1" in
-i) export INTERACTIVE=1;;
-d) export DELAY="$2"; shift;;
-v) export VERBOSE="$(($VERBOSE + 1))";;
-q) export VERBOSE="$(($VERBOSE - 1))";;
-n) export SAVE_CONFIG=0;;
-c) export SAVE_OVERLAY=1;;
-b|--create-backup) export CONF_BACKUP="$2" NEED_IMAGE=1; shift;;
-r|--restore-backup) export CONF_RESTORE="$2" NEED_IMAGE=1; shift;;
-l|--list-backup) export CONF_BACKUP_LIST=1; break;;
-f) export CONF_IMAGE="$2"; shift;;
-F|--force) export FORCE=1;;
-T|--test) export TEST=1;;
-h|--help) export HELP=1; break;;
-*)
echo "Invalid option: $1"
exit 1
;;
*) break;;
esac
shift;
done
export CONFFILES=/tmp/sysupgrade.conffiles
export CONF_TAR=/tmp/sysupgrade.tgz
export ARGV="$*"
export ARGC="$#"
解析选项。\(ARGV是参数列表,\)ARGC是参数个数。
选项中有-d, -b, -r, -f时,由于这些选项都要带一个参数,所以使用了shift去减少\(ARGV和\)ARGC的值。
CONFFILES 和 CONF_TAR 是两个临时文件,后面会用到。
sysupgrade openwrt.bin
--> ARGV="openwrt.bin", ARGC=1
sysupgrade -b config.backup
--> ARGV为空,ARGC=0
判断参数合法
[ -n "$ARGV" -a -n "$NEED_IMAGE" ] && {
cat <<-EOF
-b|--create-backup and -r|--restore-backup do not perform a firmware upgrade.
Do not specify both -b|-r and a firmware image.
EOF
exit 1
}
如果sysupgrade附带参数-b或-r时,则$NEED_IMAGE=1
,否则为空
当$NEED_IMAGE=1
时,我们希望ARGV是空的,否则就是出错,则输出帮助信息,并退出。
例如:
sysupgrade -b config.backup
,此时$NEED_IMAGE=1
, ARGV为空,合法sysupgrade -b config.backup openwrt.bin
,此时$NEED_IMAGE=1
, ARGV为"openwrt.bin",参数多了,错误。
# hooks
sysupgrade_image_check="platform_check_image"
[ $SAVE_OVERLAY = 0 -o ! -d /overlay/etc ] && \
sysupgrade_init_conffiles="add_uci_conffiles" || \
sysupgrade_init_conffiles="add_overlayfiles"
带-c参数,且"/overlay/etc"目录存在 --> sysupgrade_init_conffiles="add_overlayfiles"
否则 --> sysupgrade_init_conffiles="add_uci_conffiles"
这里会影响要备份的配置文件
include /lib/upgrade
包含lib/upgrade目录下的所有文件
[ "$1" = "nand" ] && nand_upgrade_stage2 $@
命令指定nand时,则调用nand_upgrade_stage2函数,例如sysupgrade nand openwrt.bin
。 暂时使用spi flash,不讨论这里。
backup list
add_uci_conffiles() {
local file="$1"
( find $(sed -ne '/^[[:space:]]*$/d; /^#/d; p' \
/etc/sysupgrade.conf /lib/upgrade/keep.d/* 2>/dev/null) \
-type f 2>/dev/null;
opkg list-changed-conffiles ) | sort -u > "$file"
return 0
}
if [ $CONF_BACKUP_LIST -eq 1 ]; then
add_uci_conffiles "$CONFFILES"
cat "$CONFFILES"
rm -f "$CONFFILES"
exit 0
fi
列出一份文件列表,放入/tmp/sysupgrade.conffiles,打印出来,然后删掉。文件列表:
find $(sed -ne '/^[[:space:]]*$/d; /^#/d; p' /etc/sysupgrade.conf /lib/upgrade/keep.d/* 2>/dev/null) -type f 2>/dev/null
opkg list-changed-conffiles
create backup
do_save_conffiles() {
local conf_tar="${1:-$CONF_TAR}"
[ -z "$(rootfs_type)" ] && {
echo "Cannot save config while running from ramdisk."
ask_bool 0 "Abort" && exit
return 0
}
run_hooks "$CONFFILES" $sysupgrade_init_conffiles
ask_bool 0 "Edit config file list" && vi "$CONFFILES"
v "Saving config files..."
[ "$VERBOSE" -gt 1 ] && TAR_V="v" || TAR_V=""
tar c${TAR_V}zf "$conf_tar" -T "$CONFFILES" 2>/dev/null
rm -f "$CONFFILES"
}
if [ -n "$CONF_BACKUP" ]; then
do_save_conffiles "$CONF_BACKUP"
exit $?
fi
-b 如果指定打包文件时,$CONF_BACKUP 为那个文件名。则此时按如下流程来生成备份文件:
do_save_conffiles
-> sysupgrade_init_conffiles
-> add_uci_conffiles
-> tar czf /tmp/backup.tgz -T /tmp/sysupgrade.conffiles
-> rm -f /tmp/sysupgrade.conffiles
restore
if [ -n "$CONF_RESTORE" ]; then
if [ "$CONF_RESTORE" != "-" ] && [ ! -f "$CONF_RESTORE" ]; then
echo "Backup archive '$CONF_RESTORE' not found."
exit 1
fi
[ "$VERBOSE" -gt 1 ] && TAR_V="v" || TAR_V=""
tar -C / -x${TAR_V}zf "$CONF_RESTORE"
exit $?
fi
sysupgrade -r config.tgz --> tar -C / -xzf config.tgz
解压,覆盖到/目录下
image check
for check in $sysupgrade_image_check; do
( eval "$check \"\$ARGV\"" ) || {
if [ $FORCE -eq 1 ]; then
echo "Image check '$check' failed but --force given - will update anyway!"
break
else
echo "Image check '$check' failed."
exit 1
fi
}
done
sysupgrade openwrt.bin --> 检查bin文件:platform_check_image openwrt.bin
lib/upgrade/platform.sh 中定义platform_check_image函数,取.bin文件的头部,检查magic number
upgrade backup
if [ -n "$CONF_IMAGE" ]; then
case "$(get_magic_word $CONF_IMAGE cat)" in
# .gz files
1f8b) ;;
*)
echo "Invalid config file. Please use only .tar.gz files"
exit 1
;;
esac
get_image "$CONF_IMAGE" "cat" > "$CONF_TAR"
export SAVE_CONFIG=1
elif ask_bool $SAVE_CONFIG "Keep config files over reflash"; then
[ $TEST -eq 1 ] || do_save_conffiles
export SAVE_CONFIG=1
else
export SAVE_CONFIG=0
fi
在升级时会先保存配置文件到/tmp/sysupgrade.tgz
- -f 指定配置文件
- 交互模式 ask_bool 可以获取输入值,如果不在交互模式,则ask_bool的第一个参数就是默认值。
$SAVE_CONFIG默认为1, 这里调用do_save_conffiles保存当前系统的配置文件。
upgrade
if [ -n "$(rootfs_type)" ]; then
v "Switching to ramdisk..."
run_ramfs '. /lib/functions.sh; include /lib/upgrade; do_upgrade'
else
do_upgrade
fi
- rootfs_type = "overlayfs" ,执行第一个逻辑
- run_ramfs, 在/tmp/root下安装一个临时ramdisk,最后再执行do_upgrade
- do_upgrade -> platform_do_upgrade ->
get_image "$1" | mtd -j "$CONF_TAR" write - "firmware"
mtd工具在写入时,会把$CONF_TAR文件整合进入jffs2分区,可以看到打印信息:
Appending jffs2 data from /tmp/sysupgrade.tgz to firmware...