I have (or rather had :( ) a Glass running the XE8 version of software. It did not receive any automatic updates since it was rooted (as expected).
I tried to update it to XE12 using the system image from https://developers.google.com/glass/tools-downloads/system, and now it won't boot.
I can see the screen light up for a moment when it tries to boot, but the Glass logo does not come up. Instead, it just reboots itself over and over. Sometimes the screen flashes white instead of the usual reddish-gray.
I can still boot to bootloader using the hardware method. I have tried flashing XE11 but the result is the same.
I have a couple of questions that I think could be related to the problem:
1) There is a note on the system image download page regarding a "firmware change" in XE10 that prevents installation of earlier system versions (which includes XE8). Could that be my problem? Does that refer to low-level firmware change? How is that update applied when using the OTA update mechanism and can I apply it manually?
2) There is a relatively large userdata.img file in the system image .zip, however it does not get flashed using the fastboot update method:
fastboot -w update glass_1-img-947604.zip
archive does not contain 'boot.sig'
archive does not contain 'recovery.sig'
archive does not contain 'system.sig'
--------------------------------------------
Bootloader Version...: 0.5
Baseband Version.....:
Serial Number........: [device serial]
--------------------------------------------
checking product...
OKAY [ 0.002s]
sending 'boot' (4528 KB)...
OKAY [ 0.208s]
writing 'boot'...
OKAY [ 1.670s]
sending 'recovery' (5334 KB)...
OKAY [ 0.243s]
writing 'recovery'...
OKAY [ 1.797s]
sending 'system' (485525 KB)...
OKAY [ 21.414s]
writing 'system'...
OKAY [ 64.458s]
erasing 'userdata'...
OKAY [145.384s]
formatting 'userdata' partition...
Erase successful, but not automatically formatting.
File system type not supported.
OKAY [ 0.002s]
erasing 'cache'...
OKAY [102.827s]
formatting 'cache' partition...
Erase successful, but not automatically formatting.
File system type not supported.
OKAY [ 0.002s]
rebooting...
If I try to flash userdata.img explicitly I get the following error:
fastboot flash userdata userdata.img
sending 'userdata' (137046 KB)...
OKAY [ 6.049s]
writing 'userdata'...
FAILED (remote: : Sparsed Write)
Is the userdata image supposed to be written to the device?
3) Is there any way of getting the boot log using fastboot to determine what causes the crash?
Thanks.
UDPATE: I have flashed the XE8 image back and now the Glass is stuck on the empty battery screen despite being plugged in for a couple of hours. However I have had charging issues with this unit before, hopefully it gets resolved overnight.
UPDATE #2: Having been left to charge overnight the device was displaying the empty battery icon with a question mark when I got back to it in the morning, however after forced reboot it seems to have booted up fine into the old XE8 system. My next step will be to restore it to unrooted state and attempt to update it using the OTA update mechanism.
