RE: switching linux kernels

RE: switching linux kernels

[Julia Elbert]

Thanks Dan and Graham.
I am in the process of switching to 2.2.14. But, just for your knowledge, my
bug was fixed by turning off the Copy-Back Data Cache fixed my problem.
Now, back to my move to 2.2.14.
Thank you again,
Julia

		-----Original Message-----
		From:	Julia Elbert [mailto:jelbert@enerdyne.com]
		Sent:	Tuesday, September 26, 2000 9:59 AM
		To:	'Dan Malek'; 'linuxppc-embedded@lists.linuxppc.org'
		Subject:	RE: switching linux kernels


		Hi Dan,
		We don't need caching, can we turn it off?
		Thanks.

				-----Original Message-----
				From:	Dan Malek [mailto:dan@mvista.com]
				Sent:	Tuesday, September 26, 2000 8:55 AM
				To:	Julia Elbert
				Cc:
'linuxppc-embedded@lists.linuxppc.org'
				Subject:	Re: switching linux kernels


				Julia Elbert wrote:

				>                 I am switching to HardHat
2.2.13 from ppc
		2.2.13.

				> .....whatsoever, just the data is
corrupted some how.


				Depending upon the flavor of the day ppc
2.2.13, it could be
		a cache
				configuration difference.  The old 2.2.13
kernels often had
		the data
				cache in the write-through mode to avoid a
variety of bugs
		in both
				hardware and software.

				The HHLinux 2.2.13 (and all later kernels)
run with
		copy-back data
				cache and subsequent silicon errata fixes,
so there may be a
		cache
				coherency hole in the way your driver
manages it's space.


					-- Dan

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printk() ?

[Zhaobin Zhu]

Hi,

Where does printk() in linux kernel send message to ?

In which file I can find it ?

Thanks,

-
Zhaobin


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Re: printk() ?

[Tom Roberts]

Zhaobin Zhu wrote:
> Where does printk() in linux kernel send message to ?

It normally prints to the syslogd facility, which by default makes it come
out in the file /var/log/messages and also for important enough messages
comes out on the console. Note that if you write your own console driver,
you probably need to write _two_ drivers: the actual console driver used
by printk (the read routine seems to be unused), and a serial I/O driver
which will be opened by the kernel for the init process. Console drivers
themselves do not appear in the filesystem, but are registered via
register_console(). The serial I/O device needs to appear in the filesystem
for the kernel to open it for init, so should be a standard char device.


> In which file I can find it ?

kernel/printk.c


Tom Roberts	tjroberts@lucent.com

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