Hi Scott, On Wed, 20 Mar 2013 17:35:51 -0500, Scott Wood <scottw...@freescale.com> wrote:
> On 03/20/2013 05:11:57 PM, Albert ARIBAUD wrote: > > Hi Scott, > > > > On Wed, 20 Mar 2013 14:36:05 -0500, Scott Wood > > <scottw...@freescale.com> wrote: > > > > > On 03/20/2013 02:15:19 PM, Tom Rini wrote: > > > > On Wed, Mar 20, 2013 at 11:43:15AM -0500, Scott Wood wrote: > > > > > On 03/20/2013 09:58:36 AM, Wolfgang Denk wrote: > > > > > >Dear Albert, > > > > > > > > > > > >In message <20130320145927.2031b913@lilith> you wrote: > > > > > >> > > > > > >> I do understand what it does, but I still don't get why it > > > > should be > > > > > >> done, since precisely payload control transfer happens > > through > > > > > >bootm and > > > > > >> the like which already properly flush cache. > > > > > > > > > > It doesn't always happen through bootm. Standalone apps use the > > > > > "go" command. > > > > > > > > So, to try and be a bit more verbose about this, for U-Boot > > > > applications > > > > which use 'go', we still need to ensure cache coherence, which is > > why > > > > bootm does a cache flush, we need some way to flush in this case. > > > > > > It's also an issue with using the "cpu <n> release" command. > > > > > > > And in this case you aren't better served by say bootelf ? > > > > > > That wouldn't handle the "cpu release" case. In any case, "go" > > exists > > > and is currently the recommended way to launch a standalone > > application > > > in doc/README.standalone. > > > > > > > > It's a user command! How can it be dead code? I don't know of > > a > > > > > way to include a human user in a patchset... > > > > > > > > Can you hightlight what exactly causes the world today to go off > > and > > > > fail? Is the hello_world example app sufficient in this case or > > do we > > > > need something much larger? > > > > > > A user inside Freescale is running standalone performance test apps, > > > using both "go" and "cpu <n> release" (since the test needs to run > > on > > > all CPUs). They are seeing cache problems running on a T4240 if > > they > > > don't have this flush. This flush is architecturally required > > between > > > modifying/loading code and running it. > > > > Still, why make it a shell command? Since this user needs a flush with > > "go" and "cpu release", then we should add a programmatic global cache > > flush in the "go" and "cpu release" commands. > > Why add any new commands? They could all be subcommands of bootm! :-) I did not say "subcommand", I said "programmatic" -- precisely, I don't like the idea that a specific command or command form is needed to avoid a situation that can be avoided automatically. > Really, instead of adding one command, you want to modify *two* > commands to do the same thing separately, which involves changing the > syntax of both commands to accept memory range information? There is no need to change any syntax. > -Scott Amicalement, -- Albert. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
