WP8548 - Custom Yocto image not working

Legato Linux distribution (Yocto project)
1

Hi,
I have MangOH with WP8548 running this firmware:
root@swi-mdm9x15:~# cm info all Device: WP8548 IMEI: 359377060012340 FSN: LL540300071003 Firmware: SWI9X15Y_07.11.11.00 r33161 CARMD-EV-FRMWR1 2016/09/20 16:36:44 Bootloader: SWI9X15Y_07.11.11.00 r33161 CARMD-EV-FRMWR1 2016/09/20 16:36:44 root@swi-mdm9x15:~# legato version 16.07.0_cd4985660a55cc9a6f9a2ed28bcc757e
and I am trying to use own build of Yocto.
But after flashing with swiflash -m WP85XX -i yocto_wp85.cwe the device does not boot and is stuck at
Android Bootloader - UART_DM Initialized!!! [10] ERROR: No misc partition found
Is there any way to debug this?

My idea was to flash just the rootfs as I am ok with the stock kernel. But I can’t enable the fastboot mode, which according to Firmware release notes 12.2 should be available again since release 11 and which I have enabled:
AT!CUSTOM? !CUSTOM: ISVOICEN 0x01 GPIOSARENABLE 0x01 GPSENABLE 0x01 WAKEHOSTEN 0x83 NMEAENABLE 0x01 GOBIIMEN 0x01 USBECMRNDISOPTION 0x01 HSICENABLE 0x01 SINGLEAPNSWITCH 0x01 SIMLPM 0x01 BOOTQUIETDISABLE 0x01 FASTBOOTEN 0x01
So my questions are:

  1. Is there a way to debug kernel loading
  2. Is Fastboot mode working and if so how should I enable it?

Thank you
Viktor

2

The most reliable way to flash custom image is fastboot.
So instead of flashing .cwe file try to flash kernel (2k.img) and rootfs (2k.ubi) separately as mentioned here.
To enter fastboot mode use UART console, in some reason I can’t enter fastboot mode through ECM or Ethernet connected console.

3

Well, the problem was that I couldn’t get fastboot utility on my Ubuntu 16.04.1 to detect the Mangoh( and I do have the udev rule installed). Anyway it was solved for now by using the provided virtual image on a Windows 10 PC instead, where the fastboot works. If I ever figure out why it isn’t working on my Ubuntu I will update this thread. Thank you for your help.