Peter, You said "To sum it up, there's no universally applicable way of telling what will happen if keywords on the kernel command line provide conflicting information." That's fine. You've given me as good an answer as there is. Thanks for the follow up.
Mark Post -----Original Message----- From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On Behalf Of Peter Oberparleiter Sent: Thursday, September 30, 2004 6:44 AM To: [EMAIL PROTECTED] Subject: Re: VM Shutdown "Post, Mark K" <[EMAIL PROTECTED]> wrote: > Which leads to the question, if two sources of information conflict in > some way, which one "wins?" The first one? The last one? Something > else? Can we have some specific examples that can be put into a > HOWTO? :) The answer to your first question would be: it depends:) First it should be noted that zipl does not perform any kind of check on the actual contents of the kernel command line (it couldn't - only the kernel itself knows about its parameters). All it does is pass the concatenated text string to the kernel. During IPL, the kernel startup routine parses the command line left to right, evaluating each keyword or keyword/value pair and looking for routines to handle each keyword. Parsing is handled by a generic mechanism so there's no checking for conflicting input done either. Only the routines which are used for keyword handling interpret the actual parameters. As each device driver/kernel component implements its own routines, there's no defined standard behavior on how to handle conflicting information. Example: 'dasd=' parameter: defines which DASD devices are automatically activated during IPL. Specifying this keyword multiple times will extend the list of devices. 'mem=' parameter: specifies how much main memory Linux should try to use. Specifying this keyword multiple times will override previous occurrences so that only the last one will be used. To sum it up, there's no universally applicable way of telling what will happen if keywords on the kernel command line provide conflicting information. Regards, Peter Oberparleiter -- Peter Oberparleiter Linux on zSeries Development IBM Development Lab, Boeblingen/Germany ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
