Very Computer

Hi,

I guess I should know this, but in all the years of using Linux I have
never found the answer.

I always have trouble recompliling the Kernel, as when I have finished
something on my system no longer works so I have to start again, and
when I fix that problem I usually get another. To fix these problems I
usually end up reinstalling the OS, which of course detects my system
and builds the correct Kernel with all the modules.

My question is can I some how view the current Kernel setup before I
recompile so that I know what I should be choosing as options from the
config menu? Or better still can I load the current config into the
configuration options so that I only need to change the ones directly
related to my problem.

Currently I am have trouble getting the USB to work with SCSI, with SCSI
emulation on for my IDE CDRW, and with Firewire activated, only  USB is
autodetected on install so please help!

Thanks,

Neil.

  Neil
          Try make oldconfig  which will use the old .config   file which
contains the previous complie config information.

                                                     Phil Jones

On Fri, 14 Dec 2001 09:48:58 -0500, Neil Marjoram

I'm curious... what process have you normally gone through to rebuild
your kernels?  What I've always done (since I could) was during a
"make menuconfig" or "make xconfig", load in my system's kernel
options using "Load Configuration from File", but that's after I saved
a previous configuration file using "Save Configuration to File".
That way, whenever I got a updated kernel within the same family (i.e.
2.2, 2.4), I simply load up the last configuration from a saved file,
and make any tweaks I needed to, then save those changes back to the
same file, or to a new file whose name shortly describes the
modifications made--for versioning purposes.

Chris

Quote:>Currently I am have trouble getting the USB to work with SCSI, with SCSI
>emulation on for my IDE CDRW, and with Firewire activated, only  USB is
>autodetected on install so please help!

>Thanks,

>Neil.

Chris,

I have gone through all the normal config instructions, and tried all
the documentation I can, my problem is not building the kernel, but
loading the configuration to start with. I need to know how to display
or load into make xconfig the current working configuration, the
configuration that loads when you start xconfig is not that of the
running kernel - I've tried compiling without changing anything, the
system fails on reboot, mainly because it fails to detect my dual PII. I
am missing something fundamental (a brain), or perhaps my 6/7 years in
commercial Unix admin has been a total waste of time!
I know of the .config file, but initially this does not contain the
kernel setup of my system.
I think it's chicken or egg - to get it to work I need a working config
for my system - to do that I need to get it to work!!

Any thoughts?

Thanks,

Neil.

For what its worth ... do you do your recompiles in a separate directory
away from the /usr/src ?  If you do then the .config file for your original
setup will still be intact in /usr/src/linux.  It may pay to review the
.config as it is just a series of options in a text file and relates
directly to the options you get in make menuconfig (which I find more useful
than the gui's).  I got a similar but different problem which you may have
come across:

where does the module-info file come from in the /boot directory?  I am
using two alternate kernels and since upgrading from 2.4.2 there are a
number of changes I haven't worked out yet ... good luck !

On Sat, 15 Dec 2001 07:41:04 -0500, Neil Marjoram

<snipped out>

Quote:

>Chris,

>I have gone through all the normal config instructions, and tried all
>the documentation I can, my problem is not building the kernel, but
>loading the configuration to start with. I need to know how to display
>or load into make xconfig the current working configuration, the
>configuration that loads when you start xconfig is not that of the
>running kernel - I've tried compiling without changing anything, the
>system fails on reboot, mainly because it fails to detect my dual PII. I
>am missing something fundamental (a brain), or perhaps my 6/7 years in
>commercial Unix admin has been a total waste of time!
>I know of the .config file, but initially this does not contain the
>kernel setup of my system.
>I think it's chicken or egg - to get it to work I need a working config
>for my system - to do that I need to get it to work!!

Part of this depends on whether or not you are using:  1) the
distribution's supplied kernel source; 2) a updated kernel source from
the distribution makers; or 3) just a plain Linus kernel source, as
gotten from kernel.org.

Assuming (1) or (2) for the moment, if you are wanted to build the
kernel from this source for the first time, the ".config" file is a
base working configuration that you can start from.  And yes, you
probably don't want to just use this file as your initial kernel
configuration, especially if you have particular requirements like SMP
support.  So the first thing you do is to make a copy of this file,
like "cp .config /usr/src/<hostname>-kernel.conf", then do a "make
mrproper".  This make statement will erase ".config".  Then when you
do "make xconfig", you load up the alternate configuration file
"<hostname>-kernel.conf" using the button "Load Configuration from
File", and then make your initial changes to the configuration, either
to include and exclude certain kernel features (see below).  When you
are done, save the changes either to the same file, using the button
"Save Configuration to File", or to a different file--probably a
better method use--like "<hostname>-kernel.conf-<yyyymmddvv>", where
<yyyymmddvv> is similar to zone file versioning, if you're familiar
with DNS administration.

If you are using (3), you can start by using a configuration file,
like ".config", obtained from either (1) or (2) if you have them on
your system, making a copy of it as "/usr/src/<hostname>-kernel.conf".
Note that this configuration file assumes many features that will be
missing from a Linus kernel, so when you load it up during "make
xconfig", only some of the original settings will be available and
selected accordingly.  But it get you at least a starting point.
However, if you do not have any prior configuration file on your
system, and you starting from scratch with a Linus kernel, then at the
point you can only try to ensure on building a kernel that will get
the system to at least boot up into single-user mode.  That's you're
target.  The extra features needed for the system to properly boot up
into run-level 3 or 5 can be dealt during another pass-through the
kernel configuration and building phrase.

In any case, when you do "make xconfig", and load up a configuration
file if you have one, you will need to go through all the options to
make sure you have the necessary features either built into the kernel
or as a module that you want.  Again, to be able to get the system to
boot up into at least single-user mode, pay particular attention to
including driver support for devices like SCSI adapters, ReiserFS, and
so on.  It's been my habit to have the all absolute necessities built
into the kernel, not as modules.  I don't like maintaining initial RAM
disks (initrd), as I feel it to be a clumsy requirement for proper
boot up.

Chris

Quote:>Any thoughts?

>Thanks,

>Neil.