[U-Boot-Users] Re: "go addr" Question...

Robin Getz rgetz at blackfin.uclinux.org
Tue Sep 6 20:05:24 CEST 2005

>U-boot typically runs with instruction cache enabled and data cache 
>disabled (experience base: PowerPC).  This is because instruction cache 
>"just works" and is very beneficial and data cache generally causes 
>massive grief

This is how we have things set up (data cache and instruction cache on by 

Based on the fact that uncompressing an image :

icache   dcache  time boot*
  off       off   11 seconds
  off        on   10 seconds
   on       off    3 seconds
   on        on    1 second

*time to boot is based on the time to bootm to check the checksum, and 
uncompress the image, and print out "Starting Kernel at 0xnnnnnn".

Our customers want sub 2 second boot time - so we need to have both dcache 
and icache on.

If the restriction is that you can't use the go command with dcache on, 
then I can also live with that (and just put 'dcache on;' as part of the 
boot command for Linux kernels.


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