[ECOS] Re: Problem on allocate PCI memory space...

Andrew Lunn andrew.lunn@ascom.ch
Thu Sep 14 03:43:00 GMT 2000


> Actually, I think I've just worked out what the problem may be. The MMU
> setup code is not included at all in RAM startup executables, it is
> only present in the ROM monitor.

I've been here, done that for the EBSA. I needed to change the MMU
setup so that i could write to the FLASH without the MMU/CPU doing
caching and write buffering. For the EBSA i needed some of the macros
used to setup the TLB available in user applications. This required a
change to the header files. Also it needed a change to the macros that
flush the cache. On the ARM you change the TLB, flush the cache so
that the TLB is written to the DRAM, and then tell the MMU to flush
its copy of the TLB and read it from DRAM again. This last stage was
missing on the EBSA. Without that last bit it sometimes worked and
sometimes not depending on what memory i used first.

Hope this helps.

        Andrew


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