This doc contains tutorials for using CCD. These tutorials only cover using GSC CCD. Some use cases will be very similar to using CCD from ryu, servo micro, or servo v4, but these guides are not guaranteed to work for them. More detailed instructions on how to use different parts of CCD are in the GSC CCD doc.
This goes through the steps to connect SuzyQ and start using CCD.
Charge your chromebook. Suzyq can‘t charge your device. If it’s not charged, the device may run out of power while debugging.
Connect the type A side of Suzyq to your workstation.
Connect the type C part of your Suzyq to your chromebook.
Verify the CCD device exists.
Look for a device with the right vid:pid. Cr50 vid:pid is 18d1:5014. You can use lsusb to check that it shows up.
> lsusb -vd 18d1:5014
Debug connection issues. If the device doesn't show up, disconnect suzyq from the DUT and either flip it or plug it into the other port. If your device has 2 type c ports, there are 4 ways to connect suzyq. Only one works.
Port: The DUT only supports CCD on one type C port. Try the other port if CCD doesn't show up.
Orientation: Suzyq is orientation dependent, so it may be on the correct port, but it needs to be flipped.
Check basic CCD functionality. After the CCD device shows up, the cr50, ec, and ap consoles should show up in /dev/ttyUSB*
Search for console names.
> ls /dev/ttyUSB*
If you run the ls command before and after connecting suzyq, then the new devices should be the CCD consoles. The consoles are ordered. Cr50 should be the lowest ttyUSB device, then AP, and EC should have the highest number. Running ver on all of them could also let you know which one is which if you don't want to remember the order.
Open the console.
> minicom -D /dev/ttyUSB0
AP and EC consoles may be read-only depending on the CCD state. See the Setup CCD instructions to enable them. Being able to use the cr50 console is a good enough sign that your Suzyq setup is ok.
These are the most generic instructions.
There are other ways to open ccd that may be faster, but they don‘t work for all devices. You can see the other open methods in the ccd setup doc to find other ways if this way doesn’t work for you.
The entering dev mode instructions will be for clamshell devices. If your device is not a clamshell, check out the [full dev mode instructions].
Charge your chromebook. Servo V4 can charge your device, but it‘s good to charge it before setting up ccd. Servo v4 may encounter different issues if your device isn’t charged.
Connect the type A side of the micro usb cable to your workstation.
Connect the micro usb of your cable to “HOST” port of servo v4.
Update Servo V4 from the chroot.
chroot > sudo emerge servo-firmware
chroot > sudo servo_updater -b servo_v4
Connect the PD charger to the “DUT POWER” port of servo v4.
Connect the type C part of the Servo V4 to your chromebook. The DUT should now be charging through servo v4. Check that the green light in the corner of servo v4 lights up.
Verify the CCD device exists.
Look for a device with the right vid:pid. Cr50 vid:pid is 18d1:5014. You can use lsusb to check that it shows up.
> lsusb -vd 18d1:5014
Debug connection issues.
Port: The DUT only supports CCD on one type C port. Try the other port if CCD doesn't show up.
Orientation: Orientation shouldn't matter with Servo V4. If it does, please file a bug.
Charge State: Make sure the the green light in the corner of servo v4 is lit.
Connect to the Cr50 console. After the CCD device shows up, the cr50, ec, and ap consoles should show up in /dev/ttyUSB*
Search for console names.
> ls /dev/ttyUSB*
If you run the ls command before and after connecting the Servo V4 type C cable to the DUT, then the new devices should be the CCD consoles. The consoles are ordered. Cr50 should be the lowest ttyUSB device, then AP, and EC should have the highest number. Running ver on all of them could also let you know which one is which if you don‘t want to remember the order. **Servo V4 has it’s own console. It might be useful to do this step to find the device consoles**
Open the console.
> minicom -D /dev/ttyUSB1
Make sure version shows some version information.
Open CCD. Here's the most generic way to open ccd. For the full open options see Setup CCD.
Enter dev mode. These are clamshell instructions for other types of chromeOS devices refer to the full setup doc.
Boot into recovery by pressing the power button, refresh, and escape.
At the recovery screen press Ctrl+D and enter.
Use gsctool to open Cr50 from the AP. Press the power button when prompted. This will take ~5 minutes.
AP > gsctool -a -o
Set all capabilities to Always and confirm they're Always.
cr50 > ccd reset factory
cr50 > ccd
Enable Testlab Mode. Tap the power button when prompted. This will take a couple of seconds.
cr50 > ccd testlab enable
Start servod and make sure the EC console works.
* enter chroot with `cros_sdk --no-ns-pid`
* start servod
chroot > sudo servod -b $BOARD
* Check EC uart works.
chroot > dut-control ec_board
Try running a test Use autotest_dir, so you don‘t need to about what autotest packages to emerge. firmware_ECHash is just a short test. If your board doesn’t have an EC, try something else. Use firmware_FAFTSetup to verify the setup will work with faft-ec and faft-bios.
chroot > test_that $IP --autotest_dir \
~/trunk/src/third_party/autotest/files/ firmware_ECHash
Debug Setup
Cr50 capabilities: EC uart capability needs to always be accessible. Make sure UartGscTxECRx and all other capabilities are always.
cr50 > ccd
Make sure servod started using the CCD device. Verify the ccd serialname has the right format. Cr50 serialname should have the format [0-9a-f]{8}-[0-9a-f]{8}
chroot > dut-control ccd_serialname
If the control doesn't exist or the serianame is wrong try to find ccd serialname and start servod explicitly selecting it.
find serialname and use it to restart servod.
chroot > lsusb -vd 18d1:5014 | grep iSerial chroot > sudo servod -b $BOARD -s $SERIALNAME
All capabilities are Always
cr50 > ccd
Testlab mode is enabled
cr50 > ccd testlab
EC uart works
chroot > dut-control ec_board
Cr50 has a couple of ways to remove HW write protect. The biggest difference in the process is whether or not you want to open the case and whether or not you need write protect disable to be permanent.
Opening CCD might require the AP can boot. If you're relying on CCD to recover a bricked machine, you may want to do the optional CCD setup steps before flashing RO firmware.
Cr50 will disable HW write protect if you remove the battery.
Open the Case.
Remove the battery. Cr50 disables write protect when the battery is disconnected. On chromeboxes you need to remove the write protect screw.
(bob only) remove the write protect screw. Bob uses cr50 and a write protect screw. Cr50 has to disable write protect and the screw has to be removed for write protect to be disabled.
(optional) Check write protect is disabled from the AP.
AP > crossystem wpsw_cur
(optional) Reconnecting the battery will reenable write protect. You can disable SW write protect if you want to be able to rewrite RO firmware without needing to keep the battery disconnected.
AP > futility flash --wp-disable
(recommended) Run some basic commands to setup CCD. It's really easy to open cr50 with the battery removed. You might want to setup CCD while you already have the case open and the battery is disconnected. Doing these extra CCD setup steps may make it easier to recover a bricked device using CCD. These will require SuzyQ.
Open Cr50 from the AP or Cr50 console. This will happen immediately.
AP > gsctool -a -o
or
Cr50 > ccd open
Setup capabilities. This can only be done from the Cr50 console.
Enable flashing the AP/EC CCD open.
Cr50 > ccd set OverrideWP Always
Cr50 > ccd set FlashAP Always
Cr50 > ccd set FlashEC Always
Enable opening Cr50 without booting the AP.
Cr50 > ccd set OpenNoDevMode Always
Cr50 > ccd set OpenFromUSB Always
Full instructions are at Setup CCD, but here are are the basic steps. If you're unsure about a step here you should take a look at the Setup CCD doc. It goes into a lot more detail.
Open CCD. Here's the most generic way to open ccd. For the full open options see Setup CCD.
Enter dev mode. These are clamshell instructions for other types of chromeOS devices refer to the full setup doc.
Boot into recovery by pressing the power button, refresh, and escape.
At the recovery screen press Ctrl+D and enter.
Use gsctool to open Cr50 from the AP. Press the power button when prompted. This will take ~5 minutes.
AP > gsctool -a -o
Connect to the Cr50 console using SuzyQ or servo v4.
> minicom -D /dev/ttyUSB0
Disable write protect using Cr50 wp console command.
cmd to disable until cr50 reboots:
cr50 > wp disable
cmd to disable it indefinitely:
cr50 > wp disable atboot
(optional) Check HW WP is disabled. ccd open takes the AP out of dev mode, so you can reenter dev mode and check the HW WP status from the AP.
From AP (after reentering dev mode):
AP > crossystem wpsw_cur
(recommended) Setup capabilities, so you can flash the device or open ccd without being able to boot the AP.
Make flashing the AP/EC accessible without opening CCD
Cr50 > ccd set OverrideWP Always
Cr50 > ccd set FlashAP Always
Cr50 > ccd set FlashEC Always
Enable opening Cr50 without booting the AP
Cr50 > ccd set OpenNoDevMode Always
Cr50 > ccd set OpenFromUSB Always
(recommended) Disable SW WP to flash RO firmware if your board has issues disabling HW WP with the AP off.
AP > futility flash --wp-disable