Arm GNU Toolchain

I'm using the ARM GNU toolchain 13.2 rel 1.  At higher levels of optimisation the compiler emits calls to memcpy, memset etc. which I cannot resolve.   These routines are not provided by the runtime environment (this is a bare-metal embedded system).  However, I presume they're present in a (target dependent) library somewhere in this toolchain.  For example, there are many instances of libc_nano.a (and others) but I can't work out which (if any) to use.  My target is an iMXRT1062 which has a Cortex-M7 core, but I would like a generalised way to establish the correct library to link with.   I guess there's a compiler option which prevents it from emitting these calls in the first place ( is it 'freestanding'?), but I assume this would result in less efficient code. 

Hi guys, I'm having a problem with extern keyword and a variable defined in a specific memory area (section attribute). I've defined and used in my main file the following variable: static osThreadId_t LEDTaskID __attribute__((section("ram_shared"))) = NULL; When I try to "include" this variable in another C file (svc_user.c) using the extern keyword, I get the following error: .\Objects\SafetyNucleoG4.axf: Error: L6218E: Undefined symbol LEDTaskID (referred from svc_user.o). Not enough information to list image symbols. Not enough information to list load addresses in the image map. I've tried to use the following code to include the variable: extern osThreadId_t LEDTaskID; or extern osThreadId_t LEDTaskID __attribute__((section("ram_shared"))); But I get the same error (as reported above). Thanks for your help, Flavio Ps: If I comment the code in the svc_user.c file (where the variable is used as extern), the code is compiled successfully.

Hello, I include I use functions test_and_set() and clear(). Programming language C++14 and my compiler is armclang 6.18 I get the errors: Some recommendations or suggestions? Thank you in advance