[Nexus 4 Q&A, Help & Troubleshooting] tofumaster:
The first thing I did was to try wiping the cache after recovery mode, but that did not take it out of the boot loop. AFAIK, in 4.3 you can't wipe the dalvik cache from stock recovery. Something similar also happened to me on my Nexus 4 a while back and yes, wiping the cache then did the trick (also think it was 4.4). It fixed it then on my Nexus 4, but not on the current one.

The initial flash was applied OTA. (e.g. There's been an "upgrade" icon in the notifications bar for like over a year.) So you touch the notification, it tells you to reboot and install and I let it w/o paying much attention to it afterwards until I noticed that it only displayed a Google logo afterwards (for over 30 minutes). If that flash takes longer than that, I could have screwed up and interrupted it. :crying: I can't recall how long the 4.4 takes to flash.

Since it was in a boot loop, I thought I could reflash from the tgz images from here: https://developers.google.com/android/nexus/images?hl=en, but of course w/ a locked boot loader, nothing will flash.

Looking at this thread, there seems to be a "manual" way to unlock the boot loader w/o wiping the device IF the Nexus 4 was on a version younger than 4.3.

http://xdaforums.com/nexus-4/orig-development/root-root-unlock-bootloader-wipe-data-t2300480/page4 - comment 35 for "steps", somewhere else for confirmation that it's not working for 4.3 and later.

So, it seems like there is no way to reflash this phone w/ anything w/o wiping the data (4.3 and after) -- which was what this question was about.

So maybe this bears repeating (to be clear). The question is:

Is there a way to recover from a boot loop caused by an OTA update from 4.3 to 4.4 when it is a stock and unrooted rom, with a stock (locked) boot loader without losing data?

-or- Is there a way to recover the data in such a state?

Of course there seems to be a way to JTAG it, but... that scares me (since I've never done that kind of stuff): http://forensicswiki.org/wiki/JTAG_LG_E960_(Nexus_4)

But I do have another question, if I accidentally interrupted the flash, is it possible to get it going again?

This might be insightful (but probably not).

--------

mbpro:occam-krt16s tofumaster$ ./flash-all.sh
sending 'bootloader' (2203 KB)...
OKAY [ 0.072s]
writing 'bootloader'...
FAILED (remote: not supported in locked device)
finished. total time: 0.073s
rebooting into bootloader...
OKAY [ 0.001s]
finished. total time: 0.001s
sending 'radio' (45537 KB)...
OKAY [ 1.437s]
writing 'radio'...
FAILED (remote: not supported in locked device)
finished. total time: 1.438s
rebooting into bootloader...
OKAY [ 0.001s]
finished. total time: 0.001s
archive does not contain 'boot.sig'
archive does not contain 'recovery.sig'
archive does not contain 'system.sig'
archive does not contain 'vendor.img'
Creating filesystem with parameters:
Size: 6189744128
Block size: 4096
Blocks per group: 32768
Inodes per group: 8048
Inode size: 256
Journal blocks: 23612
Label:
Blocks: 1511168
Block groups: 47
Reserved block group size: 375
Created filesystem with 11/378256 inodes and 50366/1511168 blocks
Creating filesystem with parameters:
Size: 587202560
Block size: 4096
Blocks per group: 32768
Inodes per group: 7168
Inode size: 256
Journal blocks: 2240
Label:
Blocks: 143360
Block groups: 5
Reserved block group size: 39
Created filesystem with 11/35840 inodes and 4616/143360 blocks
--------------------------------------------
Bootloader Version...: MAKOZ20i
Baseband Version.....: M9615A-CEFWMAZM-2.0.1700.84
Serial Number........: 0xxxxxxxxxxxxxxb
--------------------------------------------
checking product...
OKAY [ 0.002s]
checking version-bootloader...
FAILED

Device version-bootloader is 'MAKOZ20i'.
Update requires 'MAKOZ30d'.

finished. total time: 0.010s

mbpro:occam-krt16s tofumaster$ cd ..
mbpro:Nexus4 tofumaster$ ls
occam-jwr66y-factory-74b1deab_(v4.3).tgz	occam-krt16s-factory-2006f418_(v4.4).md5
occam-krt16s	occam-krt16s-factory-2006f418_(v4.4).tgz
mbpro:Nexus4 tofumaster$ md5 occam-jwr66y-factory-74b1deab_\(v4.3\).tgz > occam-jwr66y-factory-74b1deab_\(v4.3\).md5
mbpro:Nexus4 tofumaster$ ls
occam-jwr66y-factory-74b1deab_(v4.3).md5	occam-krt16s-factory-2006f418_(v4.4).md5
occam-jwr66y-factory-74b1deab_(v4.3).tgz	occam-krt16s-factory-2006f418_(v4.4).tgz
occam-krt16s
mbpro:Nexus4 tofumaster$ cat *.md5
MD5 (occam-jwr66y-factory-74b1deab_(v4.3).tgz) = 6f6db7729bc6b8089683bc5297a09b93
MD5 (occam-krt16s-factory-2006f418_(v4.4).tgz) = e60c3077c9bc9bd106eb3077992f0d6c
mbpro:Nexus4 tofumaster$ tar xvzf occam-jwr66y-factory-74b1deab_\(v4.3\).tgz
x occam-jwr66y/
x occam-jwr66y/radio-mako-m9615a-cefwmazm-2.0.1700.84.img
x occam-jwr66y/flash-base.sh
x occam-jwr66y/bootloader-mako-makoz20i.img
x occam-jwr66y/flash-all.bat
x occam-jwr66y/image-occam-jwr66y.zip
x occam-jwr66y/flash-all.sh

mbpro:Nexus4 tofumaster$ cd occam-jwr66y
mbpro:occam-jwr66y tofumaster$ ls
bootloader-mako-makoz20i.img	flash-base.sh
flash-all.bat	image-occam-jwr66y.zip
flash-all.sh	radio-mako-m9615a-cefwmazm-2.0.1700.84.img
mbpro:occam-jwr66y tofumaster$ ./flash-all.sh
sending 'bootloader' (2201 KB)...
OKAY [ 0.072s]
writing 'bootloader'...
FAILED (remote: not supported in locked device)
finished. total time: 0.073s
rebooting into bootloader...
OKAY [ 0.001s]
finished. total time: 0.001s
sending 'radio' (54321 KB)...
OKAY [ 1.712s]
writing 'radio'...
FAILED (remote: not supported in locked device)
finished. total time: 1.713s
rebooting into bootloader...
OKAY [ 0.001s]
finished. total time: 0.001s
archive does not contain 'boot.sig'
archive does not contain 'recovery.sig'
archive does not contain 'system.sig'
archive does not contain 'vendor.img'
Creating filesystem with parameters:
Size: 6189744128
Block size: 4096
Blocks per group: 32768
Inodes per group: 8048
Inode size: 256
Journal blocks: 23612
Label:
Blocks: 1511168
Block groups: 47
Reserved block group size: 375
Created filesystem with 11/378256 inodes and 50366/1511168 blocks
Creating filesystem with parameters:
Size: 587202560
Block size: 4096
Blocks per group: 32768
Inodes per group: 7168
Inode size: 256
Journal blocks: 2240
Label:
Blocks: 143360
Block groups: 5
Reserved block group size: 39
Created filesystem with 11/35840 inodes and 4616/143360 blocks
--------------------------------------------
Bootloader Version...: MAKOZ20i
Baseband Version.....: M9615A-CEFWMAZM-2.0.1700.84
Serial Number........: 0xxxxxxxxxxxxxxb
--------------------------------------------
checking product...
OKAY [ 0.002s]
checking version-bootloader...
OKAY [ 0.002s]
checking version-baseband...
OKAY [ 0.002s]
sending 'boot' (6194 KB)...
OKAY [ 0.200s]
writing 'boot'...
FAILED (remote: not supported in locked device)
finished. total time: 0.213s

mbpro:occam-jwr66y tofumaster$ fastboot devices
0xxxxxxxxxxxxxxb	fastboot