Hello,
I need to start C functions from startup code before calling C startup (which calls main()). Reason: I have to do some selftests like a destroying RAM Test which must be done before the C-startup initialisation. I don't know any ARM assembler and find it easier to maintain C code.
I have already managed to jump to a C function and exit. I am aware that it must be pure functions - no static variables. However when I try to call a subroutine from the function something goes wrong and a abort exception occurs. It has something to do with saveing the stack pointer or so.
Can you give me a hint? How can I evaluate a return variable from the C function in assembler? Maybe someone can tell me which chapter/book to read.
Thank you
Best wishes,
Oliver D.