Undefined references in NFC

[jpolvi]

Having just got the DFU functionality working I got the task of trying to add NFC functionality to the application. The code side was not a problem since I got a c and h file that should work belonging to a similar project (but different device) from workmate.

However, there are problems. The NFC code needs some functions (nfc_t2t_setup, nfc_t2t_payload_set and nfc_t2t_emulation_start) that are apparently in the relevant library (in this case nfc_t2t_lib_gcc.a). At least nm lists these functions in the library file. Though it seems odd to me that the gcc library over 20 times as large in size as the keil library).

However, if I try to build the project the linker complains that these symbols are missing even though I have added the library to makefile. What might be the problem ? It is also complaining about some redefinitions (e.g. SystemCoreClockUpdate, SystemInit and __StackTop). These definitions are in the common linker memory settings file. Why should these definitions even be in the nfc library anyway ?

[Jørgen Holmefjord]

Can you upload your Makefile? Have you looked at the Makefiles for the NFC examples in the SDK, if there are some differences to your file?

[jpolvi]

I found the problem, though it required a close examination of the makefile. The software had not used any static libraries before so the linker command did not include the library. Adding library reference to linker command fixed the problem.

[Dusan Daniska]

Hello, I am facing the same problem with NFC_T4T. How did you achieve this? How did you add a library reference to linker command? Could you please provide more info? Thank you.

[Dusan Daniska]

I have found the solution. I needed to add following lines to Makefile:

LIB_FILES += \
$(SDK_ROOT)/components/nfc/t4t_lib/nfc_t4t_lib_gcc.a \