[U-Boot] Watchdog and u-boot command prompt

[Sachin Rane]

Hello Sir,

>Please use a reasonable recent version instead. 
For following discussion I am referring to the latest version of u-boot
source code i.e. 'u-boot-2008.10'.

I am asking a question to improve my knowledge about the Watchdog
implementation in U-Boot.

In the file 'include/watchdog.h', it has been mentioned that:
8<----------------------------------------------------------
#if defined(CONFIG_HW_WATCHDOG) && defined(CONFIG_WATCHDOG) 
#error "Configuration error: CONFIG_HW_WATCHDOG and CONFIG_WATCHDOG
can't be used together."
#endif
---------------------------------------------------------->8

It means I can't enable flags CONFIG_HW_WATCHDOG & CONFIG_WATCHDOG
together.
Am I right?
I want to use Software version of Watchdog (CONFIG_WATCHDOG).
If yes then what make the Watchdog resets inside 'serial_getc_dev()'
while the code is being being executed in infinite loop.
(The loop appears infinite if user doesn't press any key)

The routines which are related to CONFIG_WATCHDOG are available in
'cpu/ppc4xx/cpu.c'


Thanks and Regards,
Sachin