Capturing logging

[mlac]

Hi there,

I want to capture all the logs made by Zephyr and printk() calls. I want to forward these logs via USB using our custom application protocol for debugging purposes.

I first looked into using the dummy shell backend, but I don't think it's well-suited for this purpose. On second look, a custom logging backend may solve my issue.

Can you recommend a solution and possibly provide some related code?

Thanks in advance!

- Laci

[Susheel Nuguru]

I think you can use USB CDC ACM as backend in our solution (I never used it myself) but these configs in prj.conf should help

CONFIG_LOG_PRINTK=y
CONFIG_USB_DEVICE_STACK=y
CONFIG_USB_DEVICE_PRODUCT="Zephyr USB Log"
CONFIG_USB_CDC_ACM=y
CONFIG_USB_DEVICE_INITIALIZE_AT_BOOT=y
CONFIG_LOG_BACKEND_USB=y

[mlac]

I do not want to use a Zephyr-provided USB logging backend as it'd interfere with our custom USB stack and protocol. I need a custom solution.

[Susheel Nuguru]

Sorry, we do not have documentation for that. 
You most likely need to enable CONFIG_LOG_BACKEND_CUSTOM and CONFIG_USB_DEVICE_STACK but we never played with this, so we cannot give you any recommendations.