[syslinux] Problems using "configfile" dhcp option with pxelinux

[Jon Nalley]

Hello,

I have been trying to use the "configfile" option in the DHCP response
to specify a specific config file when booting.  When I specify this in
my /etc/dhcpd.conf file the kernel and initrd are transferred, but the
kernel does not boot.  I am using v2.04 of pxelinux.  I would appreciate
any help anyone might be able to give.  If I remove the "configfile"
dhcp option and rename the file to "default" the kernel boots as
expected.  I don't know if it is relevant, but I am using a headless
server (no VGA only serial output).

I have included the output from the boot and my dhcpd.conf and pxelinux
config files below:

<-- begin boot output -->
Intel(R) Boot Agent Version 4.0.17
Copyright (C) 1997-2001, Intel Corporation

Intel Base-Code, PXE-2.0 (build 083)
Copyright (C) 1997-2001, Intel Corporation

CLIENT MAC ADDR: 12 34 52 00 6A 14  
CLIENT IP: 10.5.5.253  MASK: 0.0.0.0  DHCP IP:
10.5.5.1                        
                                                                               
PXELINUX 2.04 0x3e9cc3fd  Copyright (C) 1994-2003 H. Peter Anvin
UNDI data segment at:   000902F0
UNDI data segment size: 94B0
UNDI code segment at:   000997A0
UNDI code segment size: 2020
PXE entry point found (we hope) at 997A:0106
My IP address seems to be 0A0505FD 10.5.5.253
ip=10.5.5.253:10.5.5.1:0.0.0.0:0.0.0.0
TFTP prefix: /
Trying to load: configfile
Loading /boot/bootctl/vmlinuz.....................
Loading
/boot/bootctl/initrd.img.........................................................
Ready.
<-- end boot output -->

<-- begin dhcpd.conf -->
authoritative;
ddns-update-style none;
ping-check true;
one-lease-per-client true;
update-static-leases true;
allow booting;
allow bootp;

option space pxelinux;
option pxelinux.magic      code 208 = string;
option pxelinux.configfile code 209 = text;
option pxelinux.pathprefix code 210 = text;
option pxelinux.reboottime code 211 = unsigned integer 32;

subnet 10.5.5.0 netmask 255.255.255.0 {
   default-lease-time 1800;
   max-lease-time 3600;
   next-server 10.5.5.1;
   range 10.5.5.153 10.5.5.253;
   site-option-space "pxelinux";
   append dhcp-parameter-request-list 208, 209, 210, 211;
   option pxelinux.magic f1:00:74:7e;
   option pxelinux.configfile "configfile";
   filename "/pxelinux.bin";
}
<-- end dhcpd.conf -->

<-- pxelinux config file -->
serial 0 38400
default linux
prompt 0
label linux
kernel /boot/bootctl/vmlinuz
append root=/dev/ram0 idebus=66 console=ttyS0,38400 ramdisk_size=35000
initrd=/boot/bootctl/initrd.img
<-- pxelinux config file -->

-- 
Jon Nalley