AnsweredAssumed Answered

I.MX6 SoloX M4 Problem

Question asked by Nathan Barrett on Mar 20, 2015
Latest reply on Feb 28, 2017 by niranjanbc

Hello Everyone,


I'm currently evaluating an I.MX6SX SDB and have managed to boot Linux on the A9 and a demo application on the M4.


If I boot the M4 application via 'run m4boot' in u-boot before Linux is booted, the input/output on the M4 side seems fine at 115200 baud on the FTDI usb-serial debug port.

***** MCC Virtual TTY EXAMPLE *****

Please wait :

    1) A9 peer is ready

Then press "S" to start the demo


Press "S" to start the demo :


However -- As soon as the A9 core starts running Linux, any input/output on the M4 side looks like gibberish.  It's as if the baud rate is no longer set to 115200.


For example if I press 'S' before issuing the boot command in u-boot (to start Linux) the response is "Responder task started, MCC version is 002.000" from the M4


If I press 'S" after Linux is booting, I get no response and the S does not appear as an 'S' in Teraterm.  Again, it's as if the S isn't making it through because the baud rate is mangled.


Does anyone have any idea what's going on here?