[U-Boot] [PATCH 1/2] LPC2468 support

Remco Poelstra remco.poelstra at duran-audio.com
Thu Mar 26 10:10:20 CET 2009


Jean-Christophe PLAGNIOL-VILLARD schreef:
>> No, thumb code is less efficient in terms of performance, but this 
>> single file needs thumb code. See LPC2292.
> what is the Difference?
> 
> until a real big gap please do not use thumb

IAP entries need thumb code. This is not a problem, they are only used 
for programming the internal flash of the processor, so there is no 
performance penalty for normal operation.


>> Yes I do. They are straight from the LPC2292 code, so once they were 
>> considered OK. I checked out the the write{s,l,b} functions in asm/io.h, 
>> but although they look similar, for some reason they simply don't work. 
>> Given the similarities between the write{s,l,b} and the PUT* functions, 
>> what is the problem with those? Furthermore, the ARM architecture 
>> doesn't use any kind of special instructions for accessing registers, 
>> everything is memory mapped.
> please use readx/writex

Thanks for the pointer, I'll look into those.

>> I do understand that you want the best code for U-boot, but I do not 
>> entirely agree on all points. Certainly when I look at the code already 
>> in place in U-boot.
> I'm preparing a patch series to clean the arm720t to seprate it as arch
> and avoid this borring #ifdef

Can you explain what you mean here?

Kind regards,

Remco Poelstra



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