your mail

[Dave Jones]

On Wed, Apr 28, 2004 at 08:05:35PM +0200, bit_char_g at gmx.net wrote:

 > >If you run the 2.6 kernels on older glibc's (as provided in FC1 for eg)
 > >then its going to blow up unless you boot with vdso=0
 > >
 > Where exactly do u specifiy this paramter (vdso=0) ?
 > Does it have to be in the grub.conf in the "kernel" line ? 
 > Something like 
 > "kernel /boot/vmlinuz ro root=/dev/hda1 hdc=ide-scsi vdso=0"

Yes. exactly like that.
 
 > And what does it do?

there are two possible means of making a system call to the kernel.
int 80h instruction (which is the standard way) and on everything
newer than pentium pro, we can also use sysenter (which is faster).
glibc supports both by having the kernel export a magic library
(linuxgate.so) which has a pointer to where glibc needs to jump
to to make a system call. (That page contains either an int instruction
or the necessary sysenter setup instructions depending on which
is going to be used).

 > I was looking for a list of those commands on the net and in the grub manual
 > pages, but could find anything.
 > Do u know of any place, where I could look up all those parameters and their
 > meaning ?

I think this one is undocumented right now.

		Dave