SparkFun Forums

[trelaron]

Hi folks,
i need to make some tracing campaign of my program execution on the stm32f4discovery board.
Is this possible with OpenOCD? Where i can find some documentation about?


Thanks


<sorry for my bad English I hope you understand me >

[hsutherl]

Hello trelaron,

Warning: this may be completely wrong.

Real time trace:

• For real time tracing I believe you need hardware such as J-Trace.
• I don't think OpenOCD has any support for this.
• pins PE2 - PE6 are used on the STM32F407VGT6.
• On the F4Dsicovery pin E2 is connected to MEMS chip - I don't know if that would interfere with trace.

printf** via jtag:

• OpenOCD does provide a debug message system (using the Core Debug Data Register).
• Spencer Oliver has provided an example and readme file in contrib/libdcc
• You would have to add debug_write_str() or similar statements to your code at each [subroutine entry]
• I have not tried this and don't know how performance compares to a high speed serial port.

**I said printf but there is no formatting - it support raw words, halfwords, chars, and strings.

[trelaron]

Thanks for the reply hsutherl !!