root task - debugging kernel

Marcus Brinkmann Marcus.Brinkmann at
Thu May 22 15:42:40 CEST 2003

On Wed, May 21, 2003 at 10:51:47PM +0200, Niels Möller wrote:
> I did some experiments today, following Marcus' instructions. I think
> you should use switch the first two files, like
> kernel = .../kickstart
> module = .../ia32-kernel
> module = .../sigma0
> module = .../pingpong
> I'm not sure how this works, I just guess kickstart is more multiboot
> compliant than ia32-kernel.

Right, kickstart fixes up the grub boot information and makes them accesible
to everyone by binary patching the kernel image :)  It puts a pointer to the
structure in the bootinfo field of the kernel interface page (kip).

Also information about sigma0 and the rootserver (entry point, stack
pointer, image size) is (or is not, in case of the sp) set in the kip so the
kernel can start up the initial servers.

So the whole booting support is in kickstart, while the kernel only is a
receiver of the information it needs.  The rootserver can use the bootinfo
field to get at the grub boot info (argument lines etc).

> I've been able to load Marcus' root servers. For pingpong, however, I
> don't know what to expect. Nothing interesting happened when I tried
> that, so I can't say if it worked.

See farid's mail about comport option :)  IN pingpong press escape to get
at the kernel debugger.


`Rhubarb is no Egyptian god.' GNU    marcus at
Marcus Brinkmann              The Hurd
Marcus.Brinkmann at

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