xputchar - output a character
#include <sys.h>
The xputchar() function provides a way of outputting debug or logging information. The character c may be output either to a serial port (polled) or to a memory buffer. The functions xputs() and xprintf() call xputchar() to perform their output.
A default xputchar() function is provided that writes the output to a circular buffer. The global variable xputcharSize defines the size of the buffer, which defaults to one kilobyte. The buffer is allocated via a call to kalloc() with arguments KA_XPUTCHAR and xputcharSize.
The application can override this default function.