using RTT console to print along with newlib C library in Zephyr

RE: using RTT console to print along with newlib C library in Zephyr

Håkon Alseth — Tue, 21 Sep 2021 09:57:44 GMT

Hi,

I tested your project with upstream zephyr (v2.7.0-rc2), and it does not print over rtt using printf() there either. Switch to minimal libc, then it prints.

Kind regards,

Håkon

RE: using RTT console to print along with newlib C library in Zephyr

Abdellah AF — Mon, 20 Sep 2021 15:25:35 GMT

Hi,

I posted on Github before coming here and they closed the post and told me that it was an nrf Connect sdk issue

RE: using RTT console to print along with newlib C library in Zephyr

Håkon Alseth — Mon, 20 Sep 2021 14:09:03 GMT

Hi,

I can confirm that I see the same issue. Could you register this as an issue with the zephyr project github?

https://github.com/zephyrproject-rtos/zephyr/issues

Kind regards,

Håkon

RE: using RTT console to print along with newlib C library in Zephyr

Abdellah AF — Mon, 20 Sep 2021 13:30:28 GMT

Hello,

Yes, the issue is persistent

Please find attached a test project

devzone.nordicsemi.com/.../printfNewlib.rar

RE: using RTT console to print along with newlib C library in Zephyr

Håkon Alseth — Mon, 20 Sep 2021 07:28:12 GMT

Hi,

Could you test this on a newer ncs release to see if the issue is persistent across versions?

Kind regards,

Håkon

RE: using RTT console to print along with newlib C library in Zephyr

Abdellah AF — Fri, 17 Sep 2021 14:51:01 GMT

Yes the prj.conf is the same. Printf does not print to the debug terminal.

Then I removed CONFIG_NEWLIB_LIBC=y from prj.conf and printf worked but math.h functions are no longer recognized

RE: using RTT console to print along with newlib C library in Zephyr

Håkon Alseth — Fri, 17 Sep 2021 12:35:09 GMT

I do not see why it should be. Did you look at the prj.conf and copy those into your project?

RE: using RTT console to print along with newlib C library in Zephyr

Abdellah AF — Fri, 17 Sep 2021 11:43:42 GMT

The example you provided works for me, the code I am testing uses C++ instead of C.

Do you think this is the problem ?

If yes, what would be the solution to build a cpp project ?

RE: using RTT console to print along with newlib C library in Zephyr

Abdellah AF — Fri, 17 Sep 2021 11:26:19 GMT

I am using ncs 1.5.0

RE: using RTT console to print along with newlib C library in Zephyr

Håkon Alseth — Fri, 17 Sep 2021 11:18:40 GMT

Which ncs version are you using? Here's an example showing how it works with ncs v1.6.1:

devzone.nordicsemi.com/.../hello_5F00_world_5F00_rtt_5F00_newlib_5F00_printf.zip

Kind regards,

Håkon

RE: using RTT console to print along with newlib C library in Zephyr

Abdellah AF — Fri, 17 Sep 2021 10:34:52 GMT

Yes it is set and printf works until I set "Newlib C library" then it no longer works

RE: using RTT console to print along with newlib C library in Zephyr

Håkon Alseth — Fri, 17 Sep 2021 10:12:18 GMT

Hi,

Do you have CONFIG_RTT_CONSOLE=y set?

Kind regards,

Håkon