Ncs1.2.0 cannot be upgraded to ncs1.6.0

[pengfeilaw]

I need to upgrade NCS1.2.0 to NCS1.6.0, the application firmware is downloaded successfully, but after restarting the IC, it still runs the previous application.I think there should be an error in bootloader.

Here is boot's log:

*** Booting Zephyr OS build v2.1.99-ncs1 ***
[00:00:00.003,021] [0m<inf> mcuboot: Starting bootloader[0m
[00:00:00.009,185] [0m<inf> mcuboot: Primary image: magic=bad, swap_type=0x1, copy_done=0x2, image_ok=0x2[0m
[00:00:00.019,042] [0m<inf> mcuboot: Boot source: none[0m
[00:00:00.024,505] [0m<inf> mcuboot: Swap type: test[0m
[00:00:10.972,961] [1;31m<err> mcuboot: Image in the secondary slot is not valid![0m
[00:00:11.204,101] [0m<inf> mcuboot: Bootloader chainload address offset: 0xc000[0m
[00:00:11.211,730] [0m<inf> mcuboot: Jumping to the first image slot[0m

How can this issue be solved?

Thanks.

[pengfeilaw]

I used the process ncs1.2.0\nrf\samples\nrf9160\http_application_update without own modifications.Could you please do the test yourself?I don't know why it failed.

[pengfeilaw]

It works,thanks.