platform_system_core/init/devices.h
Hung-ying Tyan 99c4a8a6b3 Mount /vendor and /odm early
Right now these two partitions are mounted in the fs stage of the init
process. As a result, many vendor/ODM files needed earlier in the boot
process (e.g., init.<hardware>.rc, fstab.<hardware>.rc,
uevent.<hardware>.rc, SELinux policy files etc) can only live on the root
partition.

To prevent vendors/ODMs from polluting the root partition, this patch makes
it possible to mount the vendor and ODM partitions in the first stage of the
init process. The fstab info of both partitions to be mounted early is
composed from new kernel cmdline arguments android.early.prefix and
android.early.fstab.

For example, with:
android.early.prefix=/sys/devices/1010000.msdc0/mmc_host/mmc0/mmc0:0001/block/mmcblk0/
android.early.fstab=mmcblk0p10+/odm+ext4+ro+verify\nmmcblk0p09+/vendor+ext4+ro+verify

the final fstab string will be:
/sys/devices/1010000.msdc0/mmc_host/mmc0/mmc0:0001/block/mmcblk0/mmcblk0p10 /odm ext4 ro verify
/sys/devices/1010000.msdc0/mmc_host/mmc0/mmc0:0001/block/mmcblk0/mmcblk0p09 /vendor ext4 ro verify

The android.early.prefix is optional. When it is missing, the final fstab
string will be directly converted from android.early.fstab.

This patch also makes sure that the early mounted partitions are dm-verity
enabled so that they are trust worthy to store system files.

BUG=27805372

Change-Id: I3cf32482a5ec65445ba3aedab2164c7ba8f12694
2016-08-17 17:21:35 +08:00

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1.2 KiB
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/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef _INIT_DEVICES_H
#define _INIT_DEVICES_H
#include <sys/stat.h>
extern void handle_device_fd();
extern void device_init(void);
enum early_device_type { EARLY_BLOCK_DEV, EARLY_CHAR_DEV };
extern int early_device_socket_open();
extern void early_device_socket_close();
extern void early_create_dev(const std::string& syspath, early_device_type dev_type);
extern int add_dev_perms(const char *name, const char *attr,
mode_t perm, unsigned int uid,
unsigned int gid, unsigned short prefix,
unsigned short wildcard);
int get_device_fd();
#endif /* _INIT_DEVICES_H */