Trouble booting M4 demos on i.MX7D SABRE

[acer]

I have a i.MX7D SABRE, trying to run demo apps for the M4 while booting linux for the main CPU. Currently running Linux imx7dsabresd 4.1.15-1.1.1+gd5d7c02 for the Cortex-A7, with default uboot.

Followed the instructions here on NXP to boot up demo apps for Cortex-M4, but to no success. Nothing is showing on the serial (Double checked COM port settings, running on PuTTY).

Tried with binaries compiled via ARM GCC with CMAKE on windows and linux, as well as a pre-built binary from here.

Am I missing anything obvious? Or are there settings that I should take a look into?

Thanks in advance.

[Carlos_Musich]

Hi Acer Wang,

have you solved your problem now?

Carlos

[falstaff]

acer​ don't use our (the Toradex) binaries for the NXP i.MX7D Sabre board, they won't work. While our modules use the same UART instance for the M4 core (UART2), we use it in a different mode (DCE vs. DTE). Our FreeRTOS release for the Colibri iMX7S/D modules configures the UART IP and pinmux in DTE mode, which won't work for Sabre.

What FreeRTOS version are you using?

Maybe you hit the same issue as josephheath​ is seeing? Beside the work around there (fixing U-Boot), you can also try FreeRTOS 1.0.1. The sources on our git repo support the NXP i.MX7D Sabre board too.

Best regards,

Stefan