Lpc2000

I assume you use GCC. You also need to change the linker script to let 
the linker know that the code is stored in flash but it will be running 
from RAM (just like the initialized variables section). When you copied 
the code to ram, you just load the address of your main routine in pc. 
If you use interrupts, you may change the MEMMAP register, but this is 
not needed because the MAM will cache the bytes used by the interrupt 
vector and it will run just as fast as in RAM. I never did this myself, 
so I have no example code to share with you, maybe someone else?

Richard Duits


tripple_toast wrote:

> Thanks for the reply.
>
> So all I need is a section of assembler in boot.s that copies the
> compiled RAM code from flash to RAM.
> I've tried the approach of altering the initialised variables routine
> without success ( my arm assembler knowledge is not so good ).
>
> Once this is copied then how does the RAM code run.  Is it a matter
> of setting PC to a RAM start address?
>
> I'm ensuring that the RAM code is not using any of the ISP RAM area
> by loading it into 0x40000200
>
> Will I need to set MEMMAP to RAM, I'm not using any IRQ's?
>
>
>
> --- In lpc2000@yahoogroups.com, Richard Duits <yahoo@r...> wrote:
> > This depends on the compiler/tools you use. With GNU you can do
> this in
> > the linker script and startup.s (similar to initialized variables).
> The
> > Keil compiler has a function attribute that lets you run some
> functions
> > from ram. Don't know about other compilers.
> >
> > Richard Duits.
> >
> >
> >
> >
> > tripple_toast wrote:
> >
> > > I have managed to store in a flash sector code that is compiled to
> > > run from RAM.  At boot I wish to copy this code from flash to RAM
> and
> > > then
> > > run the code in RAM.
> > >
> > > Is this possible using the LPC213x?
> > >
> > > What do I need to do in the boot file of the flash code to get
> the RAM
> > > code running?
> > >
> > > Thanks.
> > >
> > >
> > >
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