Re: [microblaze-uclinux] mb_vanilla can't run kernel image

[John Williams <jwilliams@xxxxxxxxxxxxxx>]

Hi (again!),

OK, so I think this one is solved.

Alfred was right re: memory (16 vs 32 MB), and the cache stuff was also 
a clue.  Basically the kernel sources have moved on assuming that 
everyone had upgraded their mbvanilla_net platforms to use the full 32MB 
of DDR, but in fact I'd never updated the platform to reflect that.  In 
particular, the cache size and number of tag bits etc.

So, it was basically an inconsistency in the hardware cache size, vs how 
big the kernel thought the cache was.

The SP2 vs SP3 thing was just a red herring.

Solution is thankfully easy, I'll put up a new version of mbvanilla_net 
(mbvanilla_net_v6_10_d) on the website shortly, once I run a few more 
tests to confirm.

The reason the problem showed up in binfmt_flat is because it uses the 
cache flush routines extensively, to make sure that the instruction 
cache is invalidated when we load a new executable.  A mismatch between 
kernel and hardware cache sizes will (did!) wreak havoc in there.

So, sorry for the confusion, hopefully this will get you moving forward.

Regards,

John

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