Syslinux - Oct 2010 - trying to chainload the normal ubuntu pxe installer

Hi syslinux experts,

So, I have a pxe boot tree that looks something like this:
/menu.cfg
/linux
 /ubuntu
  /amd64
   /meerkat (contains a mirror of the netboot ubuntu image)

If I set the following in the appropriate stanza of my dhcpd.conf (for isc
dhcpd v3), I can boot the ubuntu installer:
filename "linux/ubuntu/amd64/meerkat/pxelinux.0";
next-server <tftp_server_ip>;

I would like to provide an unchanged ubuntu installer as an option from my
normal menu so that I can pull in new distributions very easily when they
are released. I changed the above dhcpd.conf config to the following:
site-option-space "pxelinux"; # appropriate definitions are included
in the
config file
if exists dhcp-parameter-request-list {
  # Always send the PXELINUX options (specified in hexadecimal)
  option dhcp-parameter-request-list = concat(option
dhcp-parameter-request-list,d0,d1,d2,d3);
}
option pxelinux.magic f1:00:74:7e;
option pxelinux.configfile "menu.cfg";
option pxelinux.pathprefix "/";
filename "pxe_bin/pxelinux.0";
next-server <tftp_server_ip>;

In my menu.cfg, I tried the following to to chainload the ubuntu installer:
UI pxe_bin/menu.c32
PROMPT 0
MENU TITLE PXE Boot Menu

LABEL ubuntu_10_10_amd64
MENU LABEL Ubuntu 10.10 (Meerkat) AMD64
KERNEL pxe_bin/pxechain.com
APPEND <tftp_server_ip>::linux/ubuntu/amd64/meerkat/pxelinux.0

However, it locks the machine up when I try the chainload. Is it actually
possible to chainload pxelinux.0 like this?

I am using syslinux 4.0.1 file from Ubuntu 10.10 for my main pxelinux.0, and
I am using the file unchanged in the Ubuntu 10.10 netboot image. I would
think they'd be the same version, but I wanted to point it out in case it
presents a known problem.

Also, I cannot seem to find a way to change the pathprefix or the
configfile. I suspect that may cause problems if I get past the lockup. Are
there ways to override those values for the chainloaded pxelinux.0?

BTW, I am willing to consider gPXE solutions. I just didn't want to
complicate the config for my question.

I know that I can get it working by adding entries specifically in my menu,
but I am trying to boot an unchanged netboot image to make it easy to pull
in new distribution versions when they are released.

Thanks for your help,
wt

On Tue, Oct 26, 2010 at 15:29, Warren Turkal <wt at 8x8.com>
wrote:
> Hi syslinux experts,
> In my menu.cfg, I tried the following to to chainload the ubuntu installer:
> UI pxe_bin/menu.c32
> PROMPT 0
> MENU TITLE PXE Boot Menu
>
> LABEL ubuntu_10_10_amd64
> MENU LABEL Ubuntu 10.10 (Meerkat) AMD64
> KERNEL pxe_bin/pxechain.com
> APPEND <tftp_server_ip>::linux/ubuntu/amd64/meerkat/pxelinux.0
I believe there are some issues with pxechain.com at the moment (4.xx).
> However, it locks the machine up when I try the chainload. Is it actually
> possible to chainload pxelinux.0 like this?
>
> I am using syslinux 4.0.1 file from Ubuntu 10.10 for my main pxelinux.0,
and
> I am using the file unchanged in the Ubuntu 10.10 netboot image. I would
> think they'd be the same version, but I wanted to point it out in case
it
> presents a known problem.
>
> Also, I cannot seem to find a way to change the pathprefix or the
> configfile. I suspect that may cause problems if I get past the lockup. Are
> there ways to override those values for the chainloaded pxelinux.0?
COM32 config.c32
APPEND configfile directorypath

By default, PXELINUX appends what you place as a directory path.
> BTW, I am willing to consider gPXE solutions. I just didn't want to
> complicate the config for my question.
>
> I know that I can get it working by adding entries specifically in my menu,
> but I am trying to boot an unchanged netboot image to make it easy to pull
> in new distribution versions when they are released.
You'll definitely want pxechain.com to help.
> Thanks for your help,
> wt
-- 
-Gene