MTK平臺將導航地圖放到內部存儲區中後，恢復出廠設置不刪除內部存儲區的方法

在MTK軟件平臺中，如果將：device\mediateksample\k61v1_demo_64_bsp\ProjectConfig.mk中的MTK_SHARED_SDCARD = yes，那麼系統啓動之後內部存儲的FAT分區和data分區將自動合併成一個分區，對用戶看到的是比原來data分區大小還大的存儲空間，這個時候我們將在內核SDCARD(內核存儲區)中拷貝進入地圖，如果進行恢復出廠設置，這個時候對/data分區的格式化將內部存儲區也格式化掉，用什麼方法可以達到不格式化內部存儲區呢？？？以下提供這種方法：

需要修改：

修改：bootable/recovery/recovery.cpp  針對data分區恢復出廠設置的時候將mount data分區，將data分區文件刪除即可。不對data分區進行ext4fs格式化。

bootable/recovery/recovery.cpp

ifdef ATC_AOSP_ENHANCEMENT
bool erase_volume(const char* volume)
#else
static bool erase_volume(const char* volume)
#endif
{
  bool is_cache = (strcmp(volume, CACHE_ROOT) == 0);
  bool is_data = (strcmp(volume, DATA_ROOT) == 0);

  ui->SetBackground(RecoveryUI::ERASING);
  ui->SetProgressType(RecoveryUI::INDETERMINATE);

  std::vector<saved_log_file> log_files;

  if (is_cache) {
    // If we're reformatting /cache, we load any past logs
    // (i.e. "/cache/recovery/last_*") and the current log
    // ("/cache/recovery/log") into memory, so we can restore them after
    // the reformat.

    ensure_path_mounted(volume);

    struct dirent* de;
    std::unique_ptr<DIR, decltype(&closedir)> d(opendir(CACHE_LOG_DIR), closedir);
    if (d) {
      while ((de = readdir(d.get())) != nullptr) {
        if (strncmp(de->d_name, "last_", 5) == 0 || strcmp(de->d_name, "log") == 0) {
          std::string path = android::base::StringPrintf("%s/%s", CACHE_LOG_DIR, de->d_name);

          struct stat sb;
          if (stat(path.c_str(), &sb) == 0) {
            // truncate files to 512kb
            if (sb.st_size > (1 << 19)) {
              sb.st_size = 1 << 19;
            }

            std::string data(sb.st_size, '\0');
            FILE* f = fopen(path.c_str(), "rbe");
            fread(&data[0], 1, data.size(), f);
            fclose(f);

            log_files.emplace_back(saved_log_file{ path, sb, data });
          }
        }
      }
    } else {
      if (errno != ENOENT) {
        PLOG(ERROR) << "Failed to opendir " << CACHE_LOG_DIR;
      }
    }
  }

  ui->Print("Formatting %s...\n", volume);
//添加以下代碼：
 //modiy by wanneng
  #if 1
  /* Add format data/ with del files for shared sdcard */
    if(is_data) {
        if(reason && !strcmp(reason,"wipe_data_via_recovery")){
            ui->Print("this wipe data reason is %s . need format /data .\n", reason);
        }else{
            ensure_path_mounted(volume);
            DIR * dir;
            struct dirent* file;
            dir = opendir(DATA_ROOT);
            if(dir) {
                LOGE("opendir %s success\n", DATA_ROOT);
                char dir_path[MAX_PATH];
                while((file = readdir(dir)) != NULL) {
                    memset(dir_path, 0, sizeof(char)*MAX_PATH);
                    if ((!strcmp(file->d_name, "..")) ||
                            (!strcmp(file->d_name, ".")) ||
                            (!strcmp(file->d_name, "lost+found")) ||
                            (!strcmp(file->d_name, "media")) ||
                            (!strcmp(file->d_name, ".layout_version")))
                        continue;
                    /* Del other files */
                    snprintf(dir_path, sizeof(dir_path),"%s/%s",DATA_ROOT, file->d_name);
                    LOGE("Del dir : %s\n", dir_path);
                    dirUnlinkHierarchy(dir_path);
                }
                /* imotor add: modify /data/.layout_version for installd */
                FILE *fp = fopen_path("/data/.layout_version", "w");
                if (fp){
                    LOGE("write /data/.layout_version 2\n");
                    fwrite("2", 1, 1, fp);
                    fclose(fp);
                }
            } else {
                LOGE("opendir failed: %s\n", strerror(errno));
                return false;
            }
            LOGE("### format data true ###\n");
            closedir(dir);
            ensure_path_unmounted(volume);
            return true;
        }
    }
  //modiy by wanneng end 
  #endif
  //結束添加代碼
  
  ensure_path_unmounted(volume);
........................................

修改：system/core/init/Android.mk  設置成PERMISSIVE模式

system/core/init/Android.mk 
ifeq ($(strip $(MTK_BUILD_ROOT)),yes)
init_options += \
    -DALLOW_LOCAL_PROP_OVERRIDE=1 \
    -DALLOW_PERMISSIVE_SELINUX=1 \
    -DREBOOT_BOOTLOADER_ON_PANIC=1 \
    -DDUMP_ON_UMOUNT_FAILURE=1
else
init_options += \
    -DALLOW_LOCAL_PROP_OVERRIDE=0 \
    -DALLOW_PERMISSIVE_SELINUX=0 \  ####修改這裏
    -DREBOOT_BOOTLOADER_ON_PANIC=0 \
    -DDUMP_ON_UMOUNT_FAILURE=0
endif
endif
修改成：
ifeq ($(strip $(MTK_BUILD_ROOT)),yes)
init_options += \
    -DALLOW_LOCAL_PROP_OVERRIDE=1 \
    -DALLOW_PERMISSIVE_SELINUX=1 \
    -DREBOOT_BOOTLOADER_ON_PANIC=1 \
    -DDUMP_ON_UMOUNT_FAILURE=1
else
init_options += \
    -DALLOW_LOCAL_PROP_OVERRIDE=0 \
    -DALLOW_PERMISSIVE_SELINUX=1 \ ####修改這裏
    -DREBOOT_BOOTLOADER_ON_PANIC=0 \
    -DDUMP_ON_UMOUNT_FAILURE=0
endif
endif

修改：vendor/mediatek/proprietary/bootable/bootloader/lk/app/mt_boot/mt_boot.c 在recovery過程中系統重啓時，將selinux權限修改成PERMISSIVE模式，否則後面的recovery掛載data分區權限失敗。導致文件無法刪除。

vendor/mediatek/proprietary/bootable/bootloader/lk/app/mt_boot/mt_boot.c
int boot_linux_from_storage(void)
{
	int ret = 0;
#define CMDLINE_TMP_CONCAT_SIZE 110     //only for string concat, 200 bytes is enough
	char cmdline_tmpbuf[CMDLINE_TMP_CONCAT_SIZE];
	unsigned int kimg_load_addr;

#ifdef MTK_AB_OTA_UPDATER
	load_bootimg_by_suffix();
#else
	switch (g_boot_mode) {
	case NORMAL_BOOT:
	case META_BOOT:
	case ADVMETA_BOOT:
	case SW_REBOOT:
	case ALARM_BOOT:
#ifdef MTK_KERNEL_POWER_OFF_CHARGING
	case KERNEL_POWER_OFF_CHARGING_BOOT:
	case LOW_POWER_OFF_CHARGING_BOOT:
#endif
  ......................................
  	// 2 weak function for mt6572 memory preserved mode
	platform_mem_preserved_load_img();
	platform_mem_preserved_dump_mem();

	custom_port_in_kernel(g_boot_mode, cmdline_get());

	if (g_boot_hdr != NULL) {
		snprintf(cmdline_tmpbuf, CMDLINE_TMP_CONCAT_SIZE, "%s", g_boot_hdr->cmdline);
		cmdline_append(cmdline_tmpbuf);
	}

// add by Wanneng //代碼添加
printf(" Jugement g_boot_mode,add by wanneng\n");
if(g_boot_mode == RECOVERY_BOOT)
{
    cmdline_append("androidboot.selinux=permissive");
    printf("g_boot_mode = %d\n",g_boot_mode);// add by wanneng
}
else{  //代碼添加，主要是針對之前的正常啓動

#ifdef SELINUX_STATUS
#if SELINUX_STATUS == 1
#ifdef ATC_AOSP_ENHANCEMENT
	//Android O don't support disabled in init proccess. Regard it as permissive.
	cmdline_append("androidboot.selinux=permissive");
#else
	cmdline_append("androidboot.selinux=disabled");
#endif
#elif SELINUX_STATUS == 2
	cmdline_append("androidboot.selinux=permissive");
#endif
#endif
} //添加括號
	/* set verity mode to 'enforcing' in order to make dm-verity work. */
	/* after verity mode handling is implemented, please remove this line */
	cmdline_append("androidboot.veritymode=disabled");

#if defined(MTK_POWER_ON_WRITE_PROTECT) && !defined(MACH_FPGA)
#if MTK_POWER_ON_WRITE_PROTECT == 1
#if defined(MTK_EMMC_SUPPORT) || defined(MTK_UFS_BOOTING)
	write_protect_flow();
#endif
#endif
#endif


#ifdef ATC_AOSP_ENHANCEMENT
	get_config_from_metazone();
	
	cmdline_append(" ");
	strcat((char *)cmdline_tmpbuf, " ");
		if (g_usb0_speed == PROTOCOL_USB11)
			cmdline_append("usbo=full");
		else if (g_usb0_speed == PROTOCOL_USB20)
			cmdline_append("usbo=high");
		else
			cmdline_append("usbo=null");

	cmdline_append(" ");
	strcat((char *)cmdline_tmpbuf, " ");
		if (g_usb1_speed == PROTOCOL_USB11)
			cmdline_append("usb1=full");
		else if (g_usb1_speed == PROTOCOL_USB20)
			cmdline_append("usb1=high");
		else
			cmdline_append("usb1=null");

	cmdline_append(" ");
	if (g_usb0_mode == USB_DEVICE_MODE)
		cmdline_append("otg=dev");
	else if (g_usb0_mode == USB_HOST_MODE)
		cmdline_append("otg=host");
	else
		cmdline_append("otg=otg");
	cmdline_append(" ");
	if (g_usb0_dvr_mode == USB_DVR_MODE_ENABLE)
		cmdline_append("usb0=dvre");
	else if (g_usb0_dvr_mode == USB_DVR_MODE_DISABLE)
		cmdline_append("usb0=dvrd");
	else
		cmdline_append("usb0=dvrn");
	cmdline_append(" ");
	if (g_usb1_dvr_mode == USB_DVR_MODE_ENABLE)
		cmdline_append("usb1=dvre");
	else if(g_usb1_dvr_mode == USB_DVR_MODE_DISABLE)
		cmdline_append("usb1=dvrd");
	else
		cmdline_append("usb1=dvrn");

	dprintf(0, "[yl] cmdline = %s\n", cmdline_get());
#endif

	/* pass related root of trust info via SMC call */
	if (send_root_of_trust_info != NULL)
		send_root_of_trust_info();

	if (g_boot_hdr != NULL) {
		boot_linux((void *)g_boot_hdr->kernel_addr, (unsigned *)g_boot_hdr->tags_addr,
			   board_machtype(), (void *)g_boot_hdr->ramdisk_addr, g_rimg_sz);
	} else {
		boot_linux((void *)CFG_BOOTIMG_LOAD_ADDR, (unsigned *)CFG_BOOTARGS_ADDR,
			   board_machtype(), (void *)CFG_RAMDISK_LOAD_ADDR, g_rimg_sz);
	}

	while (1) ;

	return 0;
}// end of boot_linux_from_storage //修改這個函數