tequilaOS/platform_bootable_recovery
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Document instructions for using adb under recovery.

Browse source 
Fixes: 72740736
Test: N/A
Change-Id: Ifc96ed785fd80501bc6c276cb649c8cc1f05be0e
This commit is contained in:
Tao Bao 2018-02-07 09:15:36 -08:00
parent bded087f7d
commit c84a4ef053
1 changed files with 91 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

91
README.md
View file

@ -47,3 +47,94 @@ image under recovery.
1. `adb sync data` to make sure the test-dir has the images to test.
2. The test will automatically pickup and verify all `_text.png` files in
the test dir.
Using `adb` under recovery
--------------------------
When running recovery image from debuggable builds (i.e. `-eng` or `-userdebug` build variants, or
`ro.debuggable=1` in `/prop.default`), `adbd` service is enabled and started by default, which
allows `adb` communication. A device should be listed under `adb devices`, either in `recovery` or
`sideload` state.
$ adb devices
List of devices attached
1234567890abcdef recovery
Although `/sbin/adbd` shares the same binary between normal boot and recovery images, only a subset
of `adb` commands are meaningful under recovery, such as `adb root`, `adb shell`, `adb push`, `adb
pull` etc. `adb shell` works only after manually mounting `/system` from recovery menu (assuming a
valid system image on device).
## Troubleshooting
### `adb devices` doesn't show the device.
$ adb devices
List of devices attached
* Ensure `adbd` is built and running.
By default, `adbd` is always included into recovery image, as `/sbin/adbd`. `init` starts `adbd`
service automatically only in debuggable builds. This behavior is controlled by the recovery
specific `/init.rc`, whose source code is at `bootable/recovery/etc/init.rc`.
The best way to confirm a running `adbd` is by checking the serial output, which shows a service
start log as below.
[ 18.961986] c1 1 init: starting service 'adbd'...
* Ensure USB gadget has been enabled.
If `adbd` service has been started but device not shown under `adb devices`, use `lsusb(8)` (on
host) to check if the device is visible to the host.
`bootable/recovery/etc/init.rc` disables Android USB gadget (via sysfs) as part of the `fs` action
trigger, and will only re-enable it in debuggable builds (the `on property` rule will always run
_after_ `on fs`).
on fs
write /sys/class/android_usb/android0/enable 0
# Always start adbd on userdebug and eng builds
on property:ro.debuggable=1
write /sys/class/android_usb/android0/enable 1
start adbd
If device is using [configfs](https://www.kernel.org/doc/Documentation/usb/gadget_configfs.txt),
check if configfs has been properly set up in init rc scripts. See the [example
configuration](https://android.googlesource.com/device/google/wahoo/+/master/init.recovery.hardware.rc)
for Pixel 2 devices. Note that the flag set via sysfs (i.e. the one above) is no-op when using
configfs.
### `adb devices` shows the device, but in `unauthorized` state.
$ adb devices
List of devices attached
1234567890abcdef unauthorized
recovery image doesn't honor the USB debugging toggle and the authorizations added under normal boot
(because such authorization data stays in /data, which recovery doesn't mount), nor does it support
authorizing a host device under recovery. We can use one of the following options instead.
* **Option 1 (Recommended):** Authorize a host device with adb vendor keys.
For debuggable builds, an RSA keypair can be used to authorize a host device that has the private
key. The public key, defined via `PRODUCT_ADB_KEYS`, will be copied to `/adb_keys`. When starting
the host-side `adbd`, make sure the filename (or the directory) of the matching private key has been
added to `$ADB_VENDOR_KEYS`.
$ export ADB_VENDOR_KEYS=/path/to/adb/private/key
$ adb kill-server
$ adb devices
`-user` builds filter out `PRODUCT_ADB_KEYS`, so no `/adb_keys` will be included there.
Note that this mechanism applies to both of normal boot and recovery modes.
* **Option 2:** Allow `adbd` to connect without authentication.
* `adbd` is compiled with `ALLOW_ADBD_NO_AUTH` (only on debuggable builds).
* `ro.adb.secure` has a value of `0`.
Both of the two conditions need to be satisfied. Although `ro.adb.secure` is a runtime property, its
value is set at build time (written into `/prop.default`). It defaults to `1` on `-user` builds, and
`0` for other build variants. The value is overridable via `PRODUCT_DEFAULT_PROPERTY_OVERRIDES`.