Re: Forcing a serial console for the kernel

[Matthias Drochner <M.Drochner%fz-juelich.de@localhost>]

smj%cirr.com@localhost said:
> The issue I have is that if I use 'consdev com0' at the boot prompt,
> should I not be able to redirect console output to the serial port on
> a PC for   any kernel regardless of whether as long as their is driver
> support for   'com'?

Generally yes, but two cases come to mind where this doesn't work:
-If the kernel configuration defines CONS_OVERRIDE, the bootblock's
 information is ignored. (shouldn't be the case for an INSTALL kernel)
-If the BIOS does some weird console redirection, it might manipulate
 the IO address table in the BIOS data area, to hide the serial port
 from users. In this case, only a bootblock which has the console's
 "ioaddr" explicitely set (eg by installboot(8)) can take over
 the serial port. (I've recently seen such a case.)

best regards
Matthias



------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------
Forschungszentrum Juelich GmbH
52425 Juelich
Sitz der Gesellschaft: Juelich
Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498
Vorsitzende des Aufsichtsrats: MinDir'in Baerbel Brumme-Bothe
Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender),
Dr. Ulrich Krafft (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt,
Prof. Dr. Sebastian M. Schmidt
------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------