[coreboot] Where does printk(DEBUG, "msg") go after booting?

Scott Duplichan scott at notabs.org
Tue Nov 30 18:35:46 CET 2010


From: coreboot-bounces at coreboot.org [mailto:coreboot-bounces at coreboot.org] On Behalf Of Patrick Georgi
Sent: Tuesday, November 30, 2010 11:26 AM
To: coreboot at coreboot.org
Subject: Re: [coreboot] Where does printk(DEBUG, "msg") go after booting?

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Am 30.11.2010 18:16, schrieb Fengwei Zhang:
> I understand the printk(DEBUG, "msg") statement will print out msg on
> the serial port when booting. How about after booting? Where does
> printk(DEBUG, "msg") go after booting?
]"After booting" the only component that might still be active (and thus
]able to run our printk) would be SMM. That code shares the same printing
]routines, so it prints on serial, too.

One thing to watch for is the OS changing the baud rate. I notice this with
coreboot+seabios and DOS after CtrlAltDel. DOS sets the baud rate to 2400.
The serial output is still present, but the baud rate must be changed to see it.

Thanks,
Scott


Patrick
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.10 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iEYEARECAAYFAkz1M7IACgkQfp0gE8eLOvQD2ACgyY9lvqgShmNs5i9sbXjoVZEO
rLUAoKOzE7nY7Y0pVH7CE/q03k6lv51w
=Mxeu
-----END PGP SIGNATURE-----






More information about the coreboot mailing list