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2023-10-10 04:14| 来源: 网络整理| 查看: 265

openwrt的升级是使用sysupgrade工具来升级的，该工具为sbin下面的一个脚本，可以附带很多参数，但是我们一般就直接sysupgrade openwrt-ramips-mt7621-device-squashfs-sysupgrade. bin升级

参数说明-i开启交互模式-d重启前延迟，延迟秒数是传进来的-v会打印sysupgrade脚本中的一些信息，脚本中默认打印-q与-v相反-n升级后不保存配置，默认保存配置-c保存所有的改动配置文件到/etc/-b用sysupgrade.conf中指定的文件，创建.tar.gz格式备份文件-r用上步创建的.tar.gz文件，恢复配置-l列出将会备份的文件列表-f从.tar.gz恢复配置-F即使升级文件检测失败，也要升级，这个参数是危险的，慎用-T验证升级文件和.tar.gz配置文件，但不升级-h打印帮助信息

sysupgrade的升级流程查看/sbin/sysupgrade脚本可以比较直观.

1、check校验固件合法性

sysupgrade的第一步就是校验固件合法性，如下判断platform_check_image函数存在则开始执行。

type platform_check_image >/dev/null 2>/dev/null || { echo "Firmware upgrade is not implemented for this platform." exit 1 } for check in $sysupgrade_image_check; do ( eval "$check \"\$1\"" ) || { echo "Image check '$check' $1 failed." return 1 } done

该函数位于lib/upgrade/platform.sh中，根据产品的型号来判断各自的magic值。

platform_check_image() { local board=$(ramips_board_name) local magic="$(get_magic_long "$1")" [ "$#" -gt 1 ] && return 1 case "$board" in br-6475nd) [ "$magic" != "43535953" ] && { echo "Invalid image type." return 1 } return 0 ;; ubnt-erx) nand_do_platform_check "$board" "$1" return $?; ;; mt7621-*) [ "$magic" != "d00dfeed" ] && { echo "Invalid image type." return 1 } return 0; ;; esac echo "Sysupgrade is not yet supported on $board." return 1 }

我们一般会在该check函数下面添加私有的校验方式，如固件的验签等功能。

2、保存config配置文件 export SAVE_CONFIG=1

默认的SAVE_CONFIG标志为为1，所以默认要保存uci配置文件

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

保存config文件函数如下：

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" }

如果sysupgrade的时候带参数-n，sysupgrade -n openwrt-ramips-mt7621-device-squashfs-sysupgrade. bin，则会将SAVE_CONFIG=0.

3、run_hooks “” $sysupgrade_pre_upgrade

这句的意思是：运行函数sysupgrade_pre_upgrade。先介绍下run_hooks函数，定义在文件common.sh中。

run_hooks() {

localarg="$1"; shift forfunc in "$@"; do eval"$func $arg" done

}

run_hooks函数是钩子函数，其中传过来的第一个参数是函数运行的参数，其余参数为要运行的函数。

disable_watchdog() { killall watchdog ( ps | grep -v 'grep' | grep '/dev/watchdog' ) && { echo 'Could not disable watchdog' return 1 } } append sysupgrade_pre_upgrade disable_watchdog

就是在升级前，去清除watchdog进程

4、 ubus call system upgrade

调用注册到ubus进程的system路径下的update方法，update方法设置了upgrade_running变量值为1，使得在ubus上注册的服务退出时无需等待。

root@zihome:/usr/sbin# ubus list system -v 'system' @3b46ff0c "board":{} "info":{} "upgrade":{} "watchdog":{"frequency":"Integer","timeout":"Integer","stop":"Boolean"} "signal":{"pid":"Integer","signum":"Integer"} "nandupgrade":{"path":"String"} 5、do_upgrade升级

vim /sbin/sysupgrade

if [ -n "$(rootfs_type)" ]; then v "Switching to ramdisk..." (run_ramfs '. /lib/functions.sh; include /lib/upgrade; do_upgrade') & else (do_upgrade) & fi

vim /lib/upgrade/common.sh

do_upgrade() { clear_caches v "Performing system upgrade..." if type 'platform_do_upgrade' >/dev/null 2>/dev/null; then platform_do_upgrade "$ARGV" else default_do_upgrade "$ARGV" fi }

image升级，保存到对应的mtd分区，这边的PART_NAME在头部会定义为fireware

default_do_upgrade() { sync if [ "$SAVE_CONFIG" -eq 1 ]; then get_image "$1" "$2" | mtd $MTD_CONFIG_ARGS -j "$CONF_TAR" write - "${PART_NAME:-image}" else get_image "$1" "$2" | mtd write - "${PART_NAME:-image}" fi } 6、config保存/删除

保存完固件之后，就开始处理config配置文件

if [ "$SAVE_CONFIG" -eq 1 ] && type 'platform_copy_config' >/dev/null 2>/dev/null; then platform_copy_config fi if [ "$SAVE_CONFIG" -eq 0 ] && type 'platform_remove_config' >/dev/null 2>/dev/null; then platform_remove_config fi

如果需要保存配置文件，则将config拷贝到/overlay下，`这边的$CONF_TAR压缩包就是上面第二步保存的配置文件

platform_copy_config() { local board_flash=$(mtk_board_flash) case "$board_flash" in "nand"|"spi") upgrade_log "Save config" rm -rf $1/* cp -af "$CONF_TAR" $1/ sync ;; esac }

如果不需要保存则删除/overlay下的config

platform_remove_config() { local board_flash=$(mtk_board_flash) case "$board_flash" in "nand"|"spi") upgrade_log "Drop config" rm -rf $1/* ;; esac } 7、重启 v "Upgrade completed" [ -n "$DELAY" ] && sleep "$DELAY" v "Rebooting system..." upgrade_log_end reboot -f sleep 2 force_reboot

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