OpenHarmony恢复启动子系统init进程之服务启动

最新推荐文章于 2025-03-31 15:57:11 发布

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最新推荐文章于 2025-03-31 15:57:11 发布 · 3.8k 阅读

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本文详细介绍了设备从pre-init到post-fs-data阶段的启动流程，涉及初始化目录、权限设置、服务启动、挂载文件系统、加载内核驱动等多个环节。在pre-init阶段，启动ueventd、watchdog服务，创建目录并挂载vendor分区。init阶段，启动lo回环网卡，设置hostname。post-init阶段，触发各种fs阶段的命令，如early-fs、fs、post-fs、late-fs和post-fs-data。在这些阶段中，分别启动了vold、hdf_devmgr、hdf_host、inputmethodservice、updater_sa、timeservice、telephony等服务，并进行了权限和模块的配置。整个启动过程中，涉及到的硬件相关配置、系统服务和框架组件的初始化是关键步骤。

首先执行job，如果开发者的进程在启动之前需要首先执行一些操作（例如创建文件夹），可以把操作放到pre-init中先执行。一般pre-init阶段主要是为后面启动服务做准备的，比如挂载目录,设置权限，启动uevent、watchdog等,uevent主要是有些服务需要响应插拔事件才会被拉起。

执行job介绍：

job名	说明
pre-init	最先执行的job，如果开发者的进程在启动之前需要首先执行一些操作（例如创建文件夹），可以把操作放到pre-init中先执行。
init	中间执行的job，例如服务启动。
post-init	最后被执行的job，如果开发者的进程在启动完成之后需要有一些处理（如驱动初始化后再挂载设备），可以把这类操作放到该job执行。单个job最多支持30条命令（当前仅支持start/mkdir/chmod/chown/mount/loadcfg），命令名称和后面的参数（参数长度≤128字节）之间有且只能有一个空格。

pre-init,init,post-init 除了/etc/init.cfg 里定义的jobs外，也包括其他服务配置的jobs。也就是说其他服务进程也可以配置pre-init,init,post-init。

执行流程:

图为一次执行的顺序是pre-init,init,启动所有boot服务,post-init,所有Normal 服务。

pre-init

主要是启动ueventd,watch_dog, 其他的就是设置权限，挂载/data 和硬件相关的挂载目录。具体看下面注释:

{

"name" : "pre-init",

"cmds" : [

"write /proc/sys/kernel/sysrq 0",

##1、写为0表示关闭sysrq,1表示启动。 sysrq 是系统请求，在键盘上对应PrintScreen键。

## 这里是关闭了所有的请求。

"mkdir /acct/uid",

"chown root system /dev/memcg/memory.pressure_level",

"chmod 0040 /dev/memcg/memory.pressure_level",

"mkdir /dev/memcg/apps/ 0755 system system",

"mkdir /dev/memcg/system 0550 system system",

##2、设置内存压力相关的权限配置。

"start ueventd", ##3、启动ueventd 服务

"start watchdog_service", ##4、启动看门狗

"mkdir /data",

"mount_fstab /vendor/etc/fstab.${ohos.boot.hardware}", ##5、挂载vendor分区，跟硬件产品相关

"chown system system /data", ## 6、为userdata 分区会挂载在/data 目录做准备

"chmod 0771 /data", ## 可读可写可执行，其他用户只读

"mkdir /data/service 0711 root root",

"mkdir /data/service/el0 0711 root root",

"load_persist_params ", ##7、加载常驻参数,类似 persist.sys.usb.config=hdc

"chown access_token access_token /dev/access_token_id", ##8、 token id

"chmod 0666 /dev/access_token_id"

]

}

init

init 是触发所有配置文件中的init字段的命令的。

/etc/init.cfg

在init.cfg加载了"/etc/init.usb.cfg", "/etc/init.usb.configfs.cfg", /vendor/etc/init.${ohos.boot.hardware}.cfg"这几个config，会把它们的信息全部整合进来。

可以看出，在 init.cfg 中，主要是做了如下事情：

创建相关的目录，修改各设备节点的权限，配置一些参数。启动 lo 回环网卡，配置hostname为localhost， domainname为localdomain。

{

"import" : [

"/etc/init.usb.cfg",

"/etc/init.usb.configfs.cfg",

"/vendor/etc/init.${ohos.boot.hardware}.cfg"

"jobs" : [ {

"name" : "init",

"cmds" : [

"copy /proc/cmdline /dev/urandom",

"copy /system/etc/prop.default /dev/urandom",

"symlink /proc/self/fd/0 /dev/stdin",

"symlink /proc/self/fd/1 /dev/stdout",

"symlink /proc/self/fd/2 /dev/stderr",

"symlink /system/bin /bin",

"symlink /system/etc /etc",

"symlink /sys/kernel/debug /d",

"symlink /system/vendor /vendor",

"mkdir /dev/stune/foreground",

"mkdir /dev/stune/background",

"mkdir /dev/stune/top-app",

"mkdir /dev/stune/rt",

"chown system system /dev/stune",

"chown system system /dev/stune/foreground",

"chown system system /dev/stune/background",

"chown system system /dev/stune/top-app",

"chown system system /dev/stune/rt",

"chown system system /dev/stune/tasks",

"chown system system /dev/stune/foreground/tasks",

"chown system system /dev/stune/background/tasks",

"chown system system /dev/stune/top-app/tasks",

"chown system system /dev/stune/rt/tasks",

"chmod 0664 /dev/stune/tasks",

"chmod 0664 /dev/stune/foreground/tasks",

"chmod 0664 /dev/stune/background/tasks",

"chmod 0664 /dev/stune/top-app/tasks",

"chmod 0664 /dev/stune/rt/tasks",

"mkdir /dev/blkio/background",

"chown system system /dev/blkio",

"chown system system /dev/blkio/background",

"chown system system /dev/blkio/tasks",

"chown system system /dev/blkio/background/tasks",

"chmod 0664 /dev/blkio/tasks",

"chmod 0664 /dev/blkio/background/tasks",

"write /dev/blkio/blkio.weight 1000",

"write /dev/blkio/background/blkio.weight 500",

"write /dev/blkio/blkio.group_idle 0",

"write /dev/blkio/background/blkio.group_idle 0",

"mount configfs none /config nodev noexec nosuid",

"chmod 0770 /config/sdcardfs",

"chown system package_info /config/sdcardfs",

"mkdir /mnt/secure 0700 root root",

"mkdir /mnt/secure/asec 0700 root root",

"mkdir /mnt/asec 0755 root system",

"mkdir /mnt/obb 0755 root system",

"mkdir /mnt/media_rw 0750 root media_rw",

"mkdir /mnt/user 0755 root root",

"mkdir /mnt/user/0 0755 root root",

"mkdir /mnt/expand 0771 system system",

"mkdir /mnt/appfuse 0711 root root",

"mkdir /mnt/runtime 0700 root root",

"mkdir /mnt/runtime/default 0755 root root",

"mkdir /mnt/runtime/default/self 0755 root root",

"mkdir /mnt/runtime/read 0755 root root",

"mkdir /mnt/runtime/read/self 0755 root root",

"mkdir /mnt/runtime/write 0755 root root",

"mkdir /mnt/runtime/write/self 0755 root root",

"mkdir /mnt/runtime/full 0755 root root",

"mkdir /mnt/runtime/full/self 0755 root root",

"symlink /storage/self/primary /sdcard",

"symlink /storage/self/primary /mnt/sdcard",

"symlink /mnt/user/0/primary /mnt/runtime/default/self/primary",

"write /proc/sys/kernel/panic_on_oops 1",

"write /proc/sys/kernel/hung_task_timeout_secs 0",

"write /proc/cpu/alignment 4",

"write /proc/sys/kernel/sched_tunable_scaling 0",

"write /proc/sys/kernel/sched_latency_ns 10000000",

"write /proc/sys/kernel/sched_wakeup_granularity_ns 2000000",

"write /proc/sys/kernel/sched_child_runs_first 0",

"write /proc/sys/kernel/randomize_va_space 2",

"write /proc/sys/vm/mmap_min_addr 32768",

"write /proc/sys/net/ipv4/ping_group_range 0 2147483647",

"write /proc/sys/net/unix/max_dgram_qlen 600",

"write /proc/sys/kernel/sched_rt_runtime_us 950000",

"write /proc/sys/kernel/sched_rt_period_us 1000000",

"write /proc/sys/net/core/rmem_max 262144",

"write /proc/sys/net/core/wmem_max 262144",

"write /proc/sys/net/ipv4/fwmark_reflect 1",

"write /proc/sys/net/ipv6/fwmark_reflect 1",

"write /proc/sys/net/ipv4/tcp_fwmark_accept 1",

"write /proc/sys/net/ipv4/conf/all/accept_redirects 0",

"write /proc/sys/net/ipv6/conf/all/accept_redirects 0",

"chmod 0400 /proc/net/fib_trie",

"chown system system /dev/cpuctl",

"chown system system /dev/cpuctl/tasks",

"chmod 0666 /dev/cpuctl/tasks",

"write /dev/cpuctl/cpu.rt_period_us 1000000",

"write /dev/cpuctl/cpu.rt_runtime_us 950000",

"mkdir /dev/cpuset/foreground",

"copy /dev/cpuset/cpus /dev/cpuset/foreground/cpus",

"copy /dev/cpuset/mems /dev/cpuset/foreground/mems",

"mkdir /dev/cpuset/background",

"copy /dev/cpuset/cpus /dev/cpuset/background/cpus",

"copy /dev/cpuset/mems /dev/cpuset/background/mems",

"mkdir /dev/cpuset/system-background",

"copy /dev/cpuset/cpus /dev/cpuset/system-background/cpus",

"copy /dev/cpuset/mems /dev/cpuset/system-background/mems",

"mkdir /dev/cpuset/restricted",

"copy /dev/cpuset/cpus /dev/cpuset/restricted/cpus",

"copy /dev/cpuset/mems /dev/cpuset/restricted/mems",

"mkdir /dev/cpuset/top-app",

"copy /dev/cpuset/cpus /dev/cpuset/top-app/cpus",

"copy /dev/cpuset/mems /dev/cpuset/top-app/mems",

"chown system system /dev/cpuset",

"chown system system /dev/cpuset/foreground",

"chown system system /dev/cpuset/background",

"chown system system /dev/cpuset/system-background",

"chown system system /dev/cpuset/top-app",

"chown system system /dev/cpuset/restricted",

"chown system system /dev/cpuset/tasks",

"chown system system /dev/cpuset/foreground/tasks",

"chown system system /dev/cpuset/background/tasks",

"chown system system /dev/cpuset/system-background/tasks",

"chown system system /dev/cpuset/top-app/tasks",

"chown system system /dev/cpuset/restricted/tasks",

"chmod 0775 /dev/cpuset/system-background",

"chmod 0664 /dev/cpuset/foreground/tasks",

"chmod 0664 /dev/cpuset/background/tasks",

"chmod 0664 /dev/cpuset/system-background/tasks",

"chmod 0664 /dev/cpuset/top-app/tasks",

"chmod 0664 /dev/cpuset/restricted/tasks",

"chmod 0664 /dev/cpuset/tasks",

"chown system system /proc/pressure/memory",

"chmod 0664 /proc/pressure/memory",

"chown root net_bw_acct /proc/net/xt_qtaguid/ctrl",

"chown root net_bw_stats /proc/net/xt_qtaguid/stats",

"chmod 0644 /dev/xt_qtaguid",

"chown root root /dev/cg2_bpf",

"chmod 0600 /dev/cg2_bpf",

"mount bpf bpf /sys/fs/bpf nodev noexec nosuid",

"mkdir /dev/fscklogs 0770 root system",

"mount pstore pstore /sys/fs/pstore nodev noexec nosuid",

"chown system log /sys/fs/pstore",

"chmod 0550 /sys/fs/pstore",

"chown system log /sys/fs/pstore/console-ramoops",

"chmod 0440 /sys/fs/pstore/console-ramoops",

"chown system log /sys/fs/pstore/console-ramoops-0",

"chmod 0440 /sys/fs/pstore/console-ramoops-0",

"chown system log /sys/fs/pstore/pmsg-ramoops-0",

"chmod 0440 /sys/fs/pstore/pmsg-ramoops-0",

"write /proc/sys/abi/swp 1",

"symlink /proc/self/fd /dev/fd",

"export DOWNLOAD_CACHE /data/cache",

"setrlimit RLIMIT_NICE 40 40",

"setrlimit RLIMIT_NOFILE 32768 32768",

"write /sys/class/leds/vibrator/trigger transient",

"write /dev/cpu_variant:${ro.bionic.arch} ${ro.bionic.cpu_variant}",

"chmod 0444 /dev/cpu_variant:${ro.bionic.arch}",

"write /dev/cpu_variant:${ro.bionic.2nd_arch} ${ro.bionic.2nd_cpu_variant}",

"chmod 0444 /dev/cpu_variant:${ro.bionic.2nd_arch}",

"chown system system /sys/power/state",

"chown system system /sys/power/wakeup_count",

"chmod 0660 /sys/power/state",

"ifup lo",

"hostname localhost",

"domainname localdomain"

]

}

/vendor/etc/init.${ohos.boot.hardware}.cfg

主要是跟硬件产品相关的配置，这里看hi3516dv300, 可见主要是挂载了debugfs(调试子系统)，修改设备角色为 peripheral，即设备。

{

"import" : [

"init.${ro.hardware}.usb.cfg"

"jobs" : [ {

"name" : "init",

"cmds" : [

"mount debugfs /sys/kernel/debug /sys/kernel/debug mode=755",

"write /sys/kernel/debug/hisi_inno_phy/role peripheral"

]

}

]

}

foundation.cfg 用户程序框架子系统

挂载cgroup到/dev/memcg主要做了如下事情：

挂载 cgroup 的memory、cpuset、cpu、freezer这几个到 /dev/memcg 目录下 cgroups子系统： Linux CGroup全称Linux Control Group，是Linux内核的一个功能，用来限制，控制与分离一个进程组群的资源（如CPU、内存、磁盘输入输出等），其最早的名称为进程容器（process containers）。

cgroups可控制的子系统主要如下： cpu 子系统，主要限制进程的 cpu 使用率。 cpuacct 子系统，可以统计 cgroups 中的进程的 cpu 使用报告。 cpuset 子系统，可以为 cgroups 中的进程分配单独的 cpu 节点或者内存节点。 memory 子系统，可以限制进程的 memory 使用量。 blkio 子系统，可以限制进程的块设备 io。 devices 子系统，可以控制进程能够访问某些设备。 net_cls 子系统，可以标记 cgroups 中进程的网络数据包，然后可以使用 tc 模块（traffic control）对数据包进行控制。 net_prio — 这个子系统用来设计网络流量的优先级 freezer 子系统，可以挂起或者恢复 cgroups 中的进程。 ns 子系统，可以使不同 cgroups 下面的进程使用不同的 namespace hugetlb — 这个子系统主要针对于HugeTLB系统进行限制，这是一个大页文件系统。

{

"jobs" : [{

"name" : "init",

"cmds" : [

"mkdir /dev/memcg",

"mount cgroup none /dev/memcg memory",

"chown system system /dev/memcg",

"chown system system /dev/memcg/tasks",

"chown system system /dev/memcg/memory.oom_control",

"chown system system /dev/memcg/cgroup.event_control",

"chown system system /dev/memcg/memory.pressure_level",

"chmod 0755 /dev/memcg",