OHOS(3) 加載運(yùn)行參考rootfs
制作rootfs
????將system vensor updater等合并進(jìn)root，形成完整的rootfs
????提取RKSDK中rootfs.img的制作命令，制作rootfs.ext4：
????????mkfs.ext4 -d rootfs_ohos -r 1 -N 0 -m 5 -L "rootfs" -O 64bit rootfs.ext4 "2G"
燒錄運(yùn)行
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
Can't connect to hilog server. Errno: 2
[? ? 4.170347] [pid=1][Init][INFO][init.c:230]Start init first stage.
[? ? 4.170544] [pid=1][Init][INFO][init_mount.c:40]Cannot load fstab from command line, try read from fstab.required
[? ? 4.170643] [pid=1][Init][ERROR][init_mount.c:43]Failed get fstab.required
[? ? 4.170762] [pid=1][Init][INFO][init.c:209]Start init second stage.
[? ? 4.170833] [pid=1][Init][ERROR][switch_root.c:156]Failed to get new root " /usr " stat
[? ? 4.178952] [pid=1][LoopEvent][INFO][le_signal.c:75]LE_AddSignal 17 0
[? ? 4.179225] [pid=1][LoopEvent][INFO][le_signal.c:75]LE_AddSignal 15 1
[? ? 4.179653] [pid=1][Init][INFO][init.c:90]Init fd holder socket done
????init運(yùn)行起來(lái)了
使用OHOS clang musl 交叉編譯應(yīng)用
簡(jiǎn)化init(elf)
????代碼在base/startup/services/init
????main函數(shù)在main.c
????#include <signal.h>
????#include "init.h"
????#include "init_log.h"
????
????static const pid_t INIT_PROCESS_PID = 1;
????
????int main(int argc, char * const argv[])
????{
????? ? int isSecondStage = 0;
????? ? (void)signal(SIGPIPE, SIG_IGN);
????? ? // Number of command line parameters is 2
????? ? if (argc == 2 && (strcmp(argv[1], "--second-stage") == 0)) {
????? ? ? ? isSecondStage = 1;
????? ? }
????? ? if (getpid() != INIT_PROCESS_PID) {
????? ? ? ? INIT_LOGE("Process id error %d!", getpid());
????? ? ? ? return 0;
????? ? }
????? ? EnableInitLog(INIT_INFO);
????? ? if (isSecondStage == 0) {
????????????// 第一次運(yùn)行（即kernel運(yùn)行）該init
????? ? ? ? SystemPrepare();
????????????/*
????????????void SystemPrepare(void)
????????????{
????????????????// mount /dev /sys /proc等
????????????? ? MountBasicFs();
????????????????// mknod /dev/null /dev/random /dev/urandom
????????????????// 這里的思想是不對(duì)的，既然后面會(huì)用到/dev/kmsg /dev/hilog
????????????????//????????就不能想著“反正后面有uevent會(huì)處理”
????????????????//?????????應(yīng)該像使用busybox搭建rootfs那樣，這里直接‘mdev -s’把該有的都導(dǎo)出來(lái)
????????????? ? CreateDeviceNode();
????????????? ? LogInit();
????????????? ? // Make sure init log always output to /dev/kmsg.
????????????? ? EnableDevKmsg();
????????????? ? INIT_LOGI("Start init first stage.");
????????????? ? // Only ohos normal system support
????????????? ? // two stages of init.
????????????? ? // If we are in updater mode, only one stage of init.
????????????? ? if (InUpdaterMode() == 0) {
????????????????????// 第二次執(zhí)行該init
????????????? ? ? ? StartInitSecondStage();
????????????? ? }
????????????}
????????????*/
????? ? } else {
????? ? ? ? LogInit();
????? ? }
? ? ? ?SystemInit();
????????/*
????????void SystemInit(void)
????????{
????????????// 向loopevent注冊(cè)signal處理函數(shù)
????????? ? SignalInit();
????????? ? // Set up a session keyring that all processes will have access to.
????????? ? KeyCtrlGetKeyringId(KEY_SPEC_SESSION_KEYRING, 1);
????????? ? // umask call always succeeds and return the previous mask value which is not needed here
????????? ? (void)umask(DEFAULT_UMASK_INIT);
????????????// 創(chuàng)建/dev/unix/socket
????????? ? MakeDirRecursive("/dev/unix/socket", S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH);
????????? ? int sock = FdHolderSockInit();
????????? ? if (sock >= 0) {
????????? ? ? ? RegisterFdHoldWatcher(sock);
????????? ? }
????????? ? InitControlFd();
????????}
????????*/
????????// 一般不再執(zhí)行rcs
????? ? SystemExecuteRcs();
????????// 重點(diǎn)在下面兩個(gè)函數(shù)
????????// 初始化資源，解析.cfg
????????//????????吐槽：一會(huì)service，一會(huì)group，看著目錄結(jié)構(gòu)好像是挺有邏輯的，實(shí)際代碼一看，這是亂成一團(tuán)的
????? ? SystemConfig();
????????// 通過(guò)loopevent去執(zhí)行解析后已有的各種東西
????? ? SystemRun();
????? ? return 0;
????}
????所以，前面的都可以刪除重構(gòu)，沒(méi)有什么二階段、chroot /usr，ramrootfs就是根文件系統(tǒng)（產(chǎn)品成形后是不可改變其存儲(chǔ)數(shù)據(jù)的），按照自己的習(xí)慣來(lái)寫(xiě)，把'mdev -s'功能也加進(jìn)去
(待續(xù))
添加hilog hdf等必要的內(nèi)核組件
https://docs.openharmony.cn/pages/v3.2/zh-cn/device-dev/porting/porting-linux-kernel.md/
1.
????從OpenHarmony內(nèi)核代碼目錄kernel/linux/linux-5.10/drivers/staging中下拷貝hilog hisysevent到RKSDK/kernel/drivers/staging下
????RKSDK/kernel/drivers/staging/Kconfig文件內(nèi)增加如下代碼：
????source "drivers/staging/hilog/Kconfig"
????source "drivers/staging/hievent/Kconfig"
????RKSDK/kernel/drivers/staging/Makefile文件內(nèi)增加如下代碼：? ? ? ??
????obj-$(CONFIG_HILOG) ? ? ? ? ? ?+= hilog/
????obj-$(CONFIG_HISYSEVENT) ? ? ? ? += hisysevent/
????使能CONFIG_HILOG和CONFIG_HISYSEVENT
2.?
????openharmony/drivers/adapter/khdf/linux/patch_hdf.sh
????openharmony/kernel/linux/patches/linux-5.10/common_patch/hdf.patch
????這里：雖然hdf結(jié)構(gòu)在openharmony中沒(méi)問(wèn)題，但是很亂！更重要的是 代碼更亂，還很隨意?！
????搬移hdf_core為drivers/hdf，然后調(diào)整khdf/ 等，等驗(yàn)證成功，tar zcvf hdf.tgz hdf備份（或者 diff 生成patch）
????編譯hdf時(shí)會(huì)有 ‘-mgeneral-regs-only’?is incompatible with the use of floating-point types
????在arch/arm64/Makefile中去掉“-mgeneral-regs-only’”
