[U-Boot] arm: Activating dcache breaks 'usb start' and 'tftpboot' on jadecpu

Wolfgang Denk wd at denx.de
Fri Dec 3 17:55:34 CET 2010


Dear =?ISO-8859-1?Q?Matthias_Wei=DFer?=,

In message <4CF91E29.7000906 at arcor.de> you wrote:
> 
> > You said you had enabled the data cache, so why do you think these
> > accesses are not cached?
> 
> Please see arch/arm/lib/cache-cp15.c
> The code there creates 4096 page table entries (1MB each) for the whole
> 4GB address space and initializes each entry in a way that it is not
> cacheable (mmu_setup():71). It then changes the page table entries which
> are pointing to a RAM area to make these, and only these, cacheable
> (dram_bank_mmu_setup():57).

You did not mention this before. You just said: "I enabled dcache"
which for e sounds as if you did this globally.

Well, I'm not an export for AT91 in any way...

Best regards,

Wolfgang Denk

-- 
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