compiling a 2.6.x kernel

[Alma J Wetzker]

Net Llama! wrote:
> On Mon, 16 Aug 2004, Kurt Wall wrote:
> 
>>In a 1.2K blaze of typing glory, Net Llama! wrote:
>>
>>>On 08/16/2004 08:04 PM, Kurt Wall wrote:
>>>
>>>>In a 0.6K blaze of typing glory, M.W. Chang wrote:
>>>>
>>>>
>>>>>># make by itself or make all compiles everything, modules included
>>>>>>if make -j3 all modules_install
>>>>>
>>>>>thanks.
>>>>>
>>>>>I noticed that under Novell SuSe 9.1, I must run mkinitrd after building
>>>>>the kernel or the system would have a kernel panic during boot-up. Is it
>>>>>reallky mandatory for 2.6 kernel?
>>>>
>>>>
>>>>Yes, if you have modules on the file system that the kernel needs to
>>>>boot, like file system or SCSI support. It's rather difficult to boot
>>>>from, say, an XFS file system if your kernel does not have XFS file
>>>>system support built-in *and* the initrd does not have an XFS module. ;-)
>>>
>>>That's not true.  I never use an initrd, and boot XFS filesystems all
>>>the time.
>>
>>That's a heckuva trick, booting from a file system your kernel doesn't
>>support. How does the kernel know how to read the file system to mount
>>root, then? Sure, you can boot the kernel, but it will panic because
>>it can't mount the RFS. So, you either have to have XFS support compiled
>>into the kernel (what I do here) or it has to live in an initrd.
> 
> Re-read what you wrote originally.  You claimed that the kernel needed to
> have XFS support compiled in  *AND* the initrd had to have an xfs module.
> I stated that both are not required, only one.

I read Kurt's statement as:

if (!(kernel_xfs) && !(module_xfs))
     kernel panic on boot;

That is not the same as:

if ((kernel_xfs) && (module_xfs))
     kernel boots ok;

What we need it the complement of the total condition to negate the entire 
logical sequence, or:

if ((kernel_xfs) || (module_xfs))
     kernel boots ok;

If that is not the way you read it, let me know.  Your conclusions are 
identical so there shouldn't be any quibbling anyway.  (There needs to be 
support for XFS in the kernel OR in the initrd modules in order to boot from 
an xfs partition.  If there is no support in EITHER place, the kernel will not 
boot.)

     -- Alma