ColdFire MCF52233DEMO

[sharda]

I am working on ColdFire MCF52233DEMO board. The default starting address on reset is 0x00000000 for flash.I want to change this address since i am developing a bootloader for MCF52233 controller using MCF52233DEMO board.

Can anyone tell what procedure i need to follow................................

[mjbcswitzerland]

Hi

There is no way to change the reset vector address on the M52233. This should however not impose any practical restriction.

Boot loaders are positioned to handle the normal reset and can jump to the application if there is no work to be performed, causing the application to start as if it were at the reset vector location.

Assuming the application code to be started by the boot loader is linked to 0x00000800 (rather than 0x00000000) the boot can start it by executing:

    move.l  #0x00000800,a0  
    move.l  (a0),sp
    move.l  #0x00000804,a0
    move.l  (a0),a0
    jmp (a0)

This loads the stack pointer from the location 0x00000800 (normally 0x00000000) and loads the PC from 0x00000804  (normally 0x00000004). The application code excecution then starts normally.

Regards

Mark

www.uTasker.com
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