[Ltib] Forcing DEBUG for pr_debug in kernel driver through LTIB

[Franz Trierweiler]

Hello everybody

Freescale has just issued a new PDK (PDK 1.6) for the iMX25 3-stack 
evalboard. I have hardwired a SIM interface to my evalboard so that I 
can scope all electrical signals coming from that cell. The fact is that 
I am trying to debug the mxc_sim.c source file for this SIM interface. 
mxc_sim is a SIM driver. In order to achieve this, I would like to 
enable pr_debug (...) output to my console when this driver is running 
and watch all debug messages displayed.

The kernel.h shows the pr_debug macro like this:

/* If you are writing a driver, please use dev_dbg instead */
#if defined(CONFIG_DYNAMIC_PRINTK_DEBUG)
#define pr_debug(fmt, ...) do { \
   dynamic_pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \
   } while (0)
#elif defined(DEBUG)
#define pr_debug(fmt, ...) \
   printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#else
#define pr_debug(fmt, ...) \
   ({ if (0) printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__); 0; })
#endif

There seems that if I #define DEBUG somewhere then I will have the 
messages displayed (or logged) somewhere.

Is there a way of doing this properly in the LTIB configuration when 
recompiling the kernel ?

Or should I simply #define DEBUG in kernel.h? (This really does not 
sound the right way).

Or should I simply put DEBUG=ON (or something like this) in the LTIB 
perl script? (sounds also very dirty).

I really would like to make this in a clean way.

Regards,
Franz