# \[WP85\] locked in fastboot mode

**URL:** <https://forum.sierrawireless.com/t/wp85-locked-in-fastboot-mode/27131>\
**Category:** WP Series\
**Created:** [May 31, 2022, 2:50pm UTC](https://forum.sierrawireless.com/t/wp85-locked-in-fastboot-mode/27131 "2022-05-31T14:50:18Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![pierrox](https://avatars.discourse-cdn.com/v4/letter/p/db5fbb/32.png) [@pierrox](https://forum.sierrawireless.com/u/pierrox)\
**Post date:** [May 31, 2022, 2:50pm UTC](https://forum.sierrawireless.com/t/wp85-locked-in-fastboot-mode/27131/1 "2022-05-31T14:50:18Z")

</div>

After updating my FX30 3G with a custom firmware, I lost control over the device. It is locked in bootloader and the device is seen as android device from the PC. I can communicate with it using fastboot but I’m unable to make it boot on Linux again. Swiflash doesn’t detect the device as it is looking for a serial device, but no USB serial device exists at this time.

I tried flashing “kernel” and “rootfs” partitions using fastboot and images found in the “build\_bin/tmp/deploy/images/swi-mdm9x15” directory when building a custom firmware using Yocto, but with no luck. Here are the commands I tried:

```auto
$ cd build_bin/tmp/deploy/images/swi-mdm9x15
$ fastboot flash kernel ./kernel 
target didn't report max-download-size
sending 'kernel' (3924 KB)...
OKAY [0.484s]
writing 'kernel'...
OKAY [0.732s]
finished. total time: 1.217s

$ fastboot flash rootfs ./rootfs
target didn't report max-download-size
sending 'rootfs' (33920 KB)...
OKAY [4.162s]
writing 'rootfs'...
OKAY [5.833s]
finished. total time: 9.995s

$ fastboot reboot
rebooting...

finished. total time: 0.052s

```

After that, the device disconnects from USB, reboot and reconnects again in bootloader.

Any idea on what I am doing wrong or what could be done to make the device boot on linux ?