Lpc2000

Hi:
Since I do not have any special software ( I work from Linux and GCC
and Olimex board ) from board manufacturers, I am unable to understand
the mystery of boot process and how it changes the execution from
Flash to SRAM with help of MEMMAP:
1. If initially MEMMAP bits are "00", and Vectors are mapped from boot
block, how does (during booting) the boot software read the flash
memory  to undersatnd if there is a valid code there? Does the boot up
software switch MEMMAP to "01" so that it could access the flash rom?
2. The Philips AN10254 note shows that we can execute the program from
SRAM by giving MEMAP = 0x2; instruction in the main() routine.
This code must have been executed from the flash only? If so, should
the Flash rom and SRAM have the same image ? What is the state of the
PC before, during and after the execution of MEMAP = 0x2; Seems like a
"hyper jump" from flash space to SRAM space. What happens to the
pipeline at this time?

Appreciate any clarification from the group.
Thanks
- Mathew