MangOH Red with WP7702



I´ve just recieved the WP7702 parts and I want to use them in mangOH Red board.

For enabling all the functionality (IoT boards, etc) I try to load the sdef mangoh redfile from github using Developer Studio and I find the following error:

ln: failed to create symbolic link ‘’: Read-only file system
ln: failed to create symbolic link ‘’: Read-only file system
/legato/3rdParty/tinycbor/Makefile:116: recipe for target ‘lib/’ failed
make[1]: *** [lib/] Error 1

I´m using WP77 with R7 Firmware (Jan 26 2018):

  • Legato for WP77 R7 (17.11.0.wp77xx-docker-201801031728) for Windows
  • SWI9X06Y_02.13.02.00 toolchain.

Do I need to configure something more to avoid this error??

Best regards


Do you have to use dev studio or command like ok with you?


I feel more confortable with dev studio because I have no very much experience with Linux, but if is necesary I move to command line to take advantage of the whole system.

how can I switch the module From command line without loose the framework for WP85?



Hi ivand,
Can you share where to get WP7702 modules for development?
How is your progress with this device?

Thank you



Hi Mirek,

sorry for late reply.

At this time, I had to stop the development with the WP7702 because it has an issue with the Renfell IoT board (RS485 version), so I´ve had to move to WP8548 back. The WP77 doesn’t generate file descriptors for USBs detected in that port.



Hi Ivand,
thanks for answer and where you get the WP77 module? What supplier?

Thank you.


Wp77 mangoh red will be available within 3 weeks


Hi asyal,
Is Mangoh Red modyfied for WP77 or is it the same I have for WP85/75.
Thank you


It’s same for all wp modules



Just to confirm, the underlying Yocto Linux build R7 (as supplied by Sierra) for WP77xx does not have the FTDI drivers built into the kernel (as the Yocto image for WP8548 does).

So until we can build the correct ftdi driver modules (and Sierra builds them into the kernel) the Renfell serial cards can’t enumerate properly on the WP77xx devices.

NOTE: This is not a mangOH hardware problem - it’s to do with the stock Yocto/Legato build that has been supplied for the WP77. Putting the stock build into ANY WP77 device (no matter what hardware platform it’s running on) will not enable any of the FTDI devices to work…

ciao, Dave


This has been committed internally as a fix to this issue in the wp76/wp77 kernel tree.

diff --git a/arch/arm/configs/mdm9607_defconfig b/arch/arm/configs/mdm9607_defconfig
index c8550a4d850a..1151f2bff0ef 100644
--- a/arch/arm/configs/mdm9607_defconfig
+++ b/arch/arm/configs/mdm9607_defconfig
@@ -510,7 +510,8 @@ CONFIG_WLCORE=m
 # CONFIG_WLCORE_SPI is not set