[U-Boot] [RFC] command/cache: Add flush_cache command

Michael Cashwell
2013-03-21T00:27:29Z

On Mar 20, 2013, at 7:48 PM, Scott Wood <scottwood@freescale.com> wrote:

> On 03/20/2013 06:33:41 PM, Michael Cashwell wrote:
>
>> What is the purpose of limiting the memory range to be flushed? Is there a reason one might want to NOT flush certain data sitting in a dirty cache line out to memory before doing a go or boot command?
>
> Because it would take a while to flush all of RAM?

"Flushing all of RAM" is what trips me up. Fundamentally, that puts the cart in front of the horse. The goal isn't to flush all of RAM but rather to flush all of cache. Iterating over the small thing rather than the large would seem reasonably efficient.

But as you say, if there are architectures where that can't be done and you must pass GBs of physical address space (rather than KB of cache space) through some process then range limiting it does make sense.

I'm not trying to argue a point. I just want all angles to be considered.

Thanks for the enlightenment!

-Mike