[Shield Tablet Q&A, Help & Troubleshooting] tanyiachaos:
Hi, Following the recent problems with battery life and the latest version of android for NVidia K1 tablets, a friend of mine tried to restore the stock image. Sadly, we're encountering some issue with fastboot, and I haven't been able to find anything on internet that could explain what is happening.

Following the instructions from (hxxp://nvidiashieldzone.com/index.php/shield-tablet/shield-tablet-k1/shield-tablet-restore-to-stock-recovery) we are stuck when flashing the system.img:

$ fastboot flash system system.img
target reported max download size of 570425344 bytes
erasing 'system'...
OKAY [ 0.549s]
sending sparse 'system' (545106 KB)...
OKAY [ 21.143s]
writing 'system'...
OKAY [ 19.928s]
sending sparse 'system' (552714 KB)...
OKAY [ 21.482s]
writing 'system'...
OKAY [ 20.861s]
sending sparse 'system' (118407 KB)...
OKAY [ 4.622s]
writing 'system'...
FAILED (remote: (InvalidSize))
finished. total time: 93.270s

When doing a 'fastboot erase system', we don't have any issue:

fastboot erase system -w
Creating filesystem with parameters:
Size: 13176406016
Block size: 4096
Blocks per group: 32768
Inodes per group: 8128
Inode size: 256
Journal blocks: 32768
Label:
Blocks: 3216896
Block groups: 99
Reserved block group size: 791
Created filesystem with 11/804672 inodes and 91191/3216896 blocks
Creating filesystem with parameters:
Size: 1073741824
Block size: 4096
Blocks per group: 32768
Inodes per group: 8192
Inode size: 256
Journal blocks: 4096
Label:
Blocks: 262144
Block groups: 8
Reserved block group size: 63
Created filesystem with 11/65536 inodes and 8536/262144 blocks
******** Did you mean to fastboot format this partition?
target reported max download size of 570425344 bytes
erasing 'system'...
OKAY [ 0.252s]
erasing 'userdata'...
OKAY [ 1.720s]
sending 'userdata' (137154 KB)...
OKAY [ 5.025s]
writing 'userdata'...
OKAY [ 4.666s]
erasing 'cache'...
OKAY [ 0.208s]
sending 'cache' (18800 KB)...
OKAY [ 0.696s]
writing 'cache'...
OKAY [ 0.710s]
finished. total time: 13.278s

Note that when doing 'fastboot format system', it seems to be returning something a little different (bigger partition, more nodes?), and I don't know if this is expected:

$ fastboot format system
Creating filesystem with parameters:
Size: 1342177280
Block size: 4096
Blocks per group: 32768
Inodes per group: 8192
Inode size: 256
Journal blocks: 5120
Label:
Blocks: 327680
Block groups: 10
Reserved block group size: 79
Created filesystem with 11/81920 inodes and 10749/327680 blocks
target reported max download size of 570425344 bytes
erasing 'system'...
OKAY [ 0.204s]
sending 'system' (22984 KB)...
OKAY [ 0.847s]
writing 'system'...
OKAY [ 0.873s]
finished. total time: 1.924s

I did check that the image had the proper md5, so I'm really stuck at why it doesn't work. The stock image is the same one as on (hxxps://developer.nvidia.com/shield-open-source#tablet-k1)

Interestingly (or worryingly), if I try to erase system too many times in a row, the command will fail with TimeOut, but restarting the tablet fixes it everytime, and I'm able to erase / format / write again, until I get the InvalidSize error.

The tablet is currently stuck on the NVidia logo startup screen (although we can get the bootloader to start everytime).

Do you have any idea what could be happening?

Thanks!

-- tanyiachaos