Messages in this thread | | | Date | Wed, 02 Jun 2010 11:22:07 +0200 | From | Marco Stornelli <> | Subject | Re: RAMOOPS: few questions |
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Il 01/06/2010 21:32, Maxim Levitsky ha scritto: > Hi, > > I want to switch over my own patch that does more or less the same that > this driver. > > As I see this driver uses ioremap to reserve the memory. > However, I have a question about how to tell kernel that specific memory > region is reserved. > > Well, I use now mem=... to do so, but this wastes space, because the > region I need can't be near end of the RAM. >
Have you got any particular constraints?
> I tried to use 'memmap=20M$0x70000000' on kernel command line, but that > just makes kernel reboot. > I think its a bug though. > > Also, does this driver dupms all kernel log or only panic/oops message?
It dumps all, but there's a fixed size for each dump, so you can see the panic/oops information and the latest prints of the kernel before panic/oops.
> My patch actually makes kernel store actual printk buffer in fixed > location, thus it is very robust. It was rejected though in favour of > solution you eventually implemented. > > Also I would like to extend your driver to dump old contents of the ram > buffer to kernel log, so one wouldn't worry about erasing in on next > boot after crash. > Don't know when I do that though. >
ramoops uses a circular buffer of fixed size to store more information. The number of "dumps" depends on the region size of memory you use.
Regards,
Marco
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