(This guide assumes you've written a working Pinephone Pro image to an sdcard.)
Note: I own both a Pro and an older PostmarketOS edition Pinephone, both won't recognize USB-C power unless the cable is the "right way up" (this is with multiple Anker and Tripp-Lite high quality USB-C cables using the Pine64 power brick, a laptop and a desktop as a source). You may need to rotate the cable till you can determine which way is considered "up" for method A:
Method A. Boot to sdcard using the reset method:
1. Open the backplate and hold reset (pinhole top left) while inserting USB-C power.
2. Release reset after 4 seconds.
Note: If you hold reset till the sdcard boots it won't be able to see the eMMC.
Method B. Boot to sdcard using the power drain method:
1. Remove USB-C power and the battery.
2. Hold down the power button for 10 seconds, release for 3 seconds, hold down the power for 10 seconds, release the power button.
3. Re-insert the battery and follow steps from method A above.
Background:
Method A worked for me when Plasma Mobile was installed but after I wrote the Pro edition of Mobian-installer to the eMMC it bricked my phone. Through trial and error I discovered method B which worked 100% of the time where method A would always fail. It's an old trick I picked up flashing Android phones a long time ago, sometimes there's residual power hanging around that can prevent the chips from resetting properly. I performed a lot of tests (~20+) using method A vs B in different scenarios, orders and duplications to make sure it wasn't a fluke or something else that was allowing Method B to work over A.
Automatically booting to sdcard
Follow this guide: https://forum.pine64.org/showthread.php?tid=15879
Note: The dd command didn't work for me till I removed "count=4" and I pressed ctrl+c on the virtual keyboard about a minute in. That's extremely crude, no doubt there's a better way but that's what worked from me.
Just for reference (READ THE GUIDE FROM THE LINK FIRST) the command I used in Mobian (running on the sdcard) was:
sudo dd if=/dev/zero of=/dev/mmcblk2 bs=8k # Wait 1 minute, ctrl+c
Note: I own both a Pro and an older PostmarketOS edition Pinephone, both won't recognize USB-C power unless the cable is the "right way up" (this is with multiple Anker and Tripp-Lite high quality USB-C cables using the Pine64 power brick, a laptop and a desktop as a source). You may need to rotate the cable till you can determine which way is considered "up" for method A:
Method A. Boot to sdcard using the reset method:
1. Open the backplate and hold reset (pinhole top left) while inserting USB-C power.
2. Release reset after 4 seconds.
Note: If you hold reset till the sdcard boots it won't be able to see the eMMC.
Method B. Boot to sdcard using the power drain method:
1. Remove USB-C power and the battery.
2. Hold down the power button for 10 seconds, release for 3 seconds, hold down the power for 10 seconds, release the power button.
3. Re-insert the battery and follow steps from method A above.
Background:
Method A worked for me when Plasma Mobile was installed but after I wrote the Pro edition of Mobian-installer to the eMMC it bricked my phone. Through trial and error I discovered method B which worked 100% of the time where method A would always fail. It's an old trick I picked up flashing Android phones a long time ago, sometimes there's residual power hanging around that can prevent the chips from resetting properly. I performed a lot of tests (~20+) using method A vs B in different scenarios, orders and duplications to make sure it wasn't a fluke or something else that was allowing Method B to work over A.
Automatically booting to sdcard
Follow this guide: https://forum.pine64.org/showthread.php?tid=15879
Note: The dd command didn't work for me till I removed "count=4" and I pressed ctrl+c on the virtual keyboard about a minute in. That's extremely crude, no doubt there's a better way but that's what worked from me.
Just for reference (READ THE GUIDE FROM THE LINK FIRST) the command I used in Mobian (running on the sdcard) was:
sudo dd if=/dev/zero of=/dev/mmcblk2 bs=8k # Wait 1 minute, ctrl+c