Output

Using printf on the Epiphany you can send messages to a debugger. However, it can be very convenient to write directly to stdout using the Epiphany cores. For this we provide a mechanism to output information from each individual Epiphany core to the stdout of the host program. For this you simply call ebsp_message completely identically to how you would call printf in regular programs.

Example

Writing text:

ebsp_message("Hello world!"); // -> $pid: Hello world!

You can also output information for local variables using standard formatting strings:

ebsp_message("Hello world from core %i of %i!",
             bsp_pid(), bsp_nprocs()); // -> $pid: Hello world from core pid of 16!

We would not recommend outputting floating point numbers through this method, because this pulls in a lot of floating-point conversion code which takes up precious memory and might even corrupt critical memory areas used by EBSP. In a future version we will provide a lightweight floating-point conversion implementation directly in our ebsp_message implementation.

Interface

void ebsp_message(const char *format, ...)

Output a debug message printf style.

ebsp_message() outputs a debug message by sending it to shared memory So that the host processor can output it to the terminal The attributes in this definition make sure that the compiler checks the arguments for errors.

Parameters

• format: The formatting string in printf style