RTOS/PROCESSOR-SDK-DRA7X: PDK_TDA2X_1_0_10 - EVMDRA75X - TI_RTOS - CCS : printf is not consistent and stalls the execution

Sathiyan Sathiyan

Tool/software: TI-RTOS

Hi,

Our C, C++ application -- for TDA2XX / EVMDRA75X that is implemented with TI_RTOS and that which involves NIMU + QSPI + UART components from the PDK_DRA7X_1_0_10 -- has run-time problems due to the usage of printf statements.

The application executable is around 6.5MB and the execution intermittently stalls for few seconds to minutes - in our observation/debugging we see that the printf (C-statement) causes such problems.

Kindly share details on how to overcome this. One more issue is that, due to memory constraints we are not including all modules in CCS for this application and so the "system_printf" call is not possible as-of-now.

Quicker and specific response is appreciated.

Thanks,

Sathiyan

over 7 years ago

0 Stephen Molfetta over 7 years ago

TI__Expert 5725 points

Hi Sathiyan,

Which core are you running this application on?

Also, if you have UART integrated then do you really need the printf function, or can you use UART_printf?

Thanks,
Stephen

0 Brad Griffis over 7 years ago in reply to Stephen Molfetta

TI__Guru*** 125430 points

Sathiyan -- please clarify on whether your printf is printing through CCS (i.e. via JTAG) or through the UART. If it is through CCS, that will definitely cause major issues. If that's the case, TI-RTOS has a LOG_printf() function is much better, though one constraint of LOG_printf is that the console will only update when you halt the target.

0 Sathiyan Sathiyan over 7 years ago in reply to Stephen Molfetta

Intellectual 500 points

Hi Stephen,

A15 core is used.
Ok, we shall use the UART_printf. But is there any additional module or option to be enabled in CCS options or in CFG file for this?

Thanks,
Sathiyan

0 Sathiyan Sathiyan over 7 years ago in reply to Brad Griffis

Intellectual 500 points

Hi Brad Griffis,

We get the prints in CCS console window via the JTAG / emulator.
Ok, we shall try to switch to LOG_printf, but is there any CCS option or CFG entry needed for this??

Thanks,
Sathiyan

0 Stephen Molfetta over 7 years ago in reply to Sathiyan Sathiyan

TI__Expert 5725 points

I would suggest you look at the UART example in PDK - this shows how to use UART stdio functions. Essentially there is a Board_init flag needed to initialize console UART - you may be doing this already if you already have UART integrated as you mention. Nothing else should be needed from .cfg file.

A15 printf requires special setup for enabling Semihosting. If you decide to go the printf route, I would suggest you confirm you have done everything mentioned here: processors.wiki.ti.com/.../BIOS_with_GCC_(CortexA). However, using UART stdio functions is still the recommended path.

Thanks,
Stephen

0 Sathiyan Sathiyan over 7 years ago in reply to Stephen Molfetta

Intellectual 500 points

Thanks Stephen. Yes, we have followed the Semihosting enable steps for "A15 printf". And we shall consider the UART stdio function suggestion and try & get back here in case suggestion needed again.

0 Brad Griffis over 7 years ago in reply to Sathiyan Sathiyan

TI__Guru*** 125430 points

Just to be clear, if you're trying to do any kind of real-time activity, you should NOT use semi-hosting. The way semi-hosting works under the hood is that a special breakpoint gets embedded inside the printf function such that any time you call printf the target halts at the breakpoint. CCS then sees that it's at the special printf breakpoint, reads out the cio buffer, prints it to CCS, and then starts the target running again. You don't actually see that the target is halting and starting repeatedly, but it is! If you need real-time prints then you need a UART (or some other peripheral like Ethernet, etc.) involved.

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RTOS/PROCESSOR-SDK-DRA7X: PDK_TDA2X_1_0_10 - EVMDRA75X - TI_RTOS - CCS : printf is not consistent and stalls the execution