Hi,

 I'm new to Embedded system's, I want to start with RTOS on ARM7 
Micro-controller's (LPC2478). Basically my intentions are to work on 
Linux platform but I'm new for Linux as well.

 I've done some basic projects on ARM7 controller.

 So please suggest how to start with "Linux" and "RTOS" to 
implementation on LPC2478 or any compatible micro-controller.

Thanks,
John

Try this,
http://tech.groups.yahoo.com/group/nuttx/

if you have dev-essentials on your distro you can build your own
toolchain with the included buildroot ( or this 
http://www.codesourcery.com/sgpp/lite/arm/portal/release1033 )