6.3. Automatic Windows installation with Cobbler

One of the challenges for creating your own Windows network installation scenario with Cobbler is preparing the necessary files in a Linux environment. However, generating the necessary binaries can be greatly simplified by using the cobbler post trigger on the sync command. Below is an example of such a trigger, which prepares the necessary files for legacy BIOS mode boot. Boot to UEFI Mode with iPXE is simpler and can be implemented by replacing the first 2 steps and several others with creating an iPXE boot menu.

Trigger sync_post_wingen.py:

  • some of the files are created from standard ones (pxeboot.n12, bootmgr.exe) by directly replacing one string with another directly in the binary
  • in the process of changing the bootmgr.exe file, the checksum of the PE file will change and it needs to be recalculated. The trigger does this with python-pefile
  • python3-hivex is used to modify Windows boot configuration data (BCD). For pxelinux distro boot_loader in BCD, paths to winpe.wim and boot.sdi are generated as /winos/<distro_name>/boot, and for iPXE - \Boot.
  • uses wimlib-tools to replace startnet.cmd startup script in WIM image

Windows answer files (autounattended.xml) are generated using Cobbler templates, with all of its conditional code generation capabilities, depending on the Windows version, architecture (32 or 64 bit), installation profile, etc.

startup scripts for WIM images (startnet.cmd) and a script that is launched after OS installation (post_install.cmd) are also generated from templates

Post-installation actions such as installing additional software, etc., are performed using the Automatic Installation Template (win.ks).

A logically automatic network installation of Windows 7 and newer can be represented as follows:

PXE + Legacy BIOS Boot

Original files: pxeboot.n12 → bootmgr.exe → BCD → winpe.wim → startnet.cmd → autounattended.xml
Cobbler profile 1: pxeboot.001 → boot001.exe → 001 → wi001.wim → startnet.cmd → autounatten001.xml → post_install.cmd profile_name


Original files: ipxe-x86_64.efi → wimboot → bootx64.efi → BCD → winpe.wim → startnet.cmd → autounattended.xml
Cobbler profile 1: ipxe-x86_64.efi → wimboot → bootx64.efi → 001 → wi001.wim → startnet.cmd → autounatten001.xml → post_install.cmd profile_name

For older versions (Windows XP, 2003):

Original files: pxeboot.n12 → setupldr.exe → winnt.sif → post_install.cmd profile_name
Cobbler profile <xxx>: pxeboot.<xxx> → setup<xxx>.exe → wi<xxx>.sif → post_install.cmd profile_name

6.3.1. Preparing for an unattended network installation of Windows

  • dnf install python3-pefile python3-hivex wimlib-utils
  • In the server’s tftp directory, create a directory winos
mkdir /var/lib/tftpboot/winos

and copy the Windows distributions there:

dr-xr-xr-x. 1 root   root         200 Mar 23  2017 Win10_EN-x64
dr-xr-xr-x. 1 root   root         238 Aug  7  2015 Win2012-Server_EN-x64
dr-xr-xr-x. 1 root   root         220 May 17  2019 Win2016-Server_EN-x64
drwxr-xr-x. 1 root   root         236 Dec  3 22:42 Win2019-Server_EN-x64
dr-xr-xr-x. 1 root   root         788 Aug  8  2015 Win2k3-Server_EN-x64
dr-xr-xr-x. 1 root   root         196 Sep 24  2017 Win2k8-Server_EN-x64
dr-xr-xr-x. 1 root   root         132 Aug  8  2015 Win7_EN-x64
dr-xr-xr-x. 1 root   root         238 Aug  7  2015 Win8_EN-x64
dr-xr-xr-x. 1 root   root         456 Aug  8  2015 WinXp_EN-i386

Copy the following files to the distributions directories (for Windows 7 and newer):

PXE + Legacy BIOS Boot
  • pxeboot.n12
  • bootmgr.exe
  • boot/BCD
  • boot/boot.sdi
  • ipxe-x86_64.efi
  • ipxe-x86_64.efi
  • wimboot
  • boot/bootx64.efi
  • boot/BCD
  • boot/boot.sdi
  • Share /var/lib/tftpboot/winos via Samba:
vi /etc/samba/smb.conf
        path = /var/lib/tftpboot/winos
        guest ok = yes
        browseable = yes
        public = yes
        writeable = no
        printable = no
  • You can use tftpd.rules to indicate the actual locations of the bootmgr.exe and BCD files generated by the trigger.
cp /usr/lib/systemd/system/tftp.service /etc/systemd/system

Replace the line in the /etc/systemd/system/tftp.service

ExecStart=/usr/sbin/in.tftpd -s /var/lib/tftpboot
ExecStart=/usr/sbin/in.tftpd -m /etc/tftpd.rules -s /var/lib/tftpboot

Create a file /etc/tftpd.rules:

vi /etc/tftpd.rules
rg  \\                                      / # Convert backslashes to slashes
r   (BOOTFONT\.BIN)                 /winos/\1
r   (/Boot/Fonts/)(.*)                      /winos/Fonts/\2

r   (ntdetect\....)                 /winos/\1

r   (wine.\.sif)                            /WinXp_EN-i386/\1
r   (xple.)                                 /WinXp_EN-i386/\1
r   (/WinXp...-i386/)(.*)                   /winos\1\L\2

r   (wi2k.\.sif)                            /Win2k3-Server_EN-x64/\1
r   (w2k3.)                                 /Win2K3-Server_EN-x64/\1
r   (/Win2k3-Server_EN-x64/)(.*)            /winos\1\L\2

r   (boot7e.\.exe)                          /winos/Win7_EN-x64/\1
r   (/Boot/)(7E.)                           /winos/Win7_EN-x64/boot/\2

r   (boot28.\.exe)                          /winos/Win2k8-Server_EN-x64/\1
r   (/Boot/)(28.)                           /winos/Win2k8-Server_EN-x64/boot/\2

r   (boot9r.\.exe)                          /winos/Win2019-Server_EN-x64/\1
r   (/Boot/)(9r.)                           /winos/Win2019-Server_EN-x64/boot/\2

r   (boot6e.\.exe)                          /winos/Win2016-Server_EN-x64/\1
r   (/Boot/)(6e.)                           /winos/Win2016-Server_EN-x64/boot/\2

r   (boot2e.\.exe)                          /winos/Win2012-Server_EN-x64/\1
r   (/Boot/)(2e.)                           /winos/Win2012-Server_EN-x64/boot/\2

r   (boot81.\.exe)                          /winos/Win8_EN-x64/\1
r   (/Boot/)(B8.)                           /winos/Win8_EN-x64/boot/\2

r   (boot1e.\.exe)                          /winos/Win10_EN-x64/\1
r   (/Boot/)(1E.)                           /winos/Win10_EN-x64/boot/\2
  • Add information about Windows distributions to the distro_signatures.json file
"windows": {
 "2003": {
 "2008": {
 "2012": {
 "2016": {
 "2019": {
 "XP": {
 "7": {
 "8": {
 "10": {
  • Add trigger /usr/lib/python3.9/site-packages/cobbler/modules/sync_post_wingen.py

6.3.2. Cobbler Windows Templates

  • /var/lib/tftpboot/winos/startnet.template is used to generate /Windows/System32/startnet.cmd script in WIM image.



ping -n 10 >nul
md \tmp
cd \tmp
ipconfig /all | find "DHCP Server" > dhcp
ipconfig /all | find "IPv4 Address" > ipaddr
FOR /F "eol=- tokens=2 delims=:" %%i in (dhcp) do set dhcp=%%i
FOR  %%i in (%dhcp%) do set dhcp=%%i
FOR /F "eol=- tokens=2 delims=:(" %%i in (ipaddr) do set ipaddr=%%i

net use y: \\@@http_server@@\Public /user:install install
#set $distro_dir = '\\\\' + $http_server + '\\WINOS\\' + $distro_name
net use z: $distro_dir /user:install install
set exit_code=%ERRORLEVEL%
IF %exit_code% EQU 0 GOTO GETNAME
echo "Can't mount network drive"
goto EXIT

y:\windows\bind\nslookup.exe %ipaddr% | find "name =" > wsname
for /f "eol=- tokens=2 delims==" %%i in (wsname) do echo %%i > ws
for /f "eol=- tokens=1 delims=." %%i in (ws) do set wsname=%%i
FOR  %%i in (%wsname%) do set wsname=%%i

#set $unattended = "set UNATTENDED_ORIG=Z:\\sources\\" + $kernel_options["sif"]
set UNATTENDED=X:\tmp\autounattended.xml

echo off
FOR /F "tokens=1 delims=!" %%l in (%UNATTENDED_ORIG%) do (
   IF "%%l"=="            <ComputerName>*</ComputerName>" (
     echo             ^<ComputerName^>%wsname%^<^/ComputerName^>>> %UNATTENDED%
   ) else (
     echo %%l>> %UNATTENDED%
echo on

set n=0
z:\sources\setup.exe /unattend:%UNATTENDED%
set /a n=n+1
ping -n 5 >nul
IF %n% lss 20 goto INSTALL

  • Templates /var/lib/tftpboot/winos/{winpe7,winpe8 }.template are standard or customized WIM PE images. The trigger copies to the directory of the corresponding distro and changes the contents of startnet.cmd based on the corresponding template and Cobbler profile. winpe7 is used for Windows 7 and Windows 2008 Server, and winpe8 for newer versions.
  • /var/lib/tftpboot/winos/win_sif.template is used to generate /var/lib/tftpboot/winos/<distro_name>/sources/autounattended.xml in case of Windows 7 and newer or winnt.sif for Windows XP, 2003


#if $arch == 'x86_64'
        #set $win_arch = 'amd64'
#else if $arch == 'i386'
        #set $win_arch = 'i386'
#end if

#set $OriSrc = '\\\\' + $http_server + '\\WINOS\\' + $distro_name + '\\' + $win_arch
#set $DevSrc = '\\Device\\LanmanRedirector\\' + $http_server + '\\WINOS\\' + $distro_name

#if $distro_name in ( 'WinXp_EN-i386', 'Win2k3-Server_EN-x64' )
floppyless = "1"
msdosinitiated = "1"
; Needed for second stage
"%Systemdrive%\post_install.cmd @@profile_name@@"
#else if $distro_name in ('Win7_EN-x64', 'Win2k8-Server_EN-x64', 'Win2012-Server_EN-x64', 'Win2016-Server_EN-x64', 'Win2019-Server_EN-x64', 'Win8_EN-x64', 'Win10_EN-x64' )
<?xml version="1.0" encoding="utf-8"?>
<unattend xmlns="urn:schemas-microsoft-com:unattend">
#if $distro_name in ( 'Win2012-Server_EN-x64' )
        <package action="configure">
                        <MetaData wcm:action="add">
#else if $distro_name in ( 'Win7_EN-x64' )
                            <Value>Windows 7 PROFESSIONAL</Value>
#else if $distro_name in ( 'Win2k8-Server_EN-x64' )
                            <Value>Windows Server 2008 R2 SERVERENTERPRISE</Value>
        <component name="Microsoft-Windows-PnpCustomizationsWinPE" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
#if $distro_name in ( 'Win2012-Server_EN-x64', 'Win8_EN-x64' )
                <PathAndCredentials wcm:action="add" wcm:keyValue="1">
                <SynchronousCommand wcm:action="add">
                    <CommandLine>c:\post_install.cmd @@profile_name@@</CommandLine>
  • The post_inst_cmd.template is used to generate a script that is launched after OS installation in the <FirstLogonCommands> autounattended.xml section, or [GuiRunOnce] in winnt.sif


CD %systemdrive%\TMP >nul 2>&1
wget.exe http://@@http_server@@/cblr/svc/op/ks/profile/%1
MOVE %1 install.cmd
todos.exe install.cmd
start /wait install.cmd
DEL /F /Q libeay32.dll >nul 2>&1
DEL /F /Q libiconv2.dll >nul 2>&1
DEL /F /Q libintl3.dll >nul 2>&1
DEL /F /Q libssl32.dll >nul 2>&1
DEL /F /Q wget.exe >nul 2>&1
DEL /F /Q %0 >nul 2>&1

For the script to work, you need to place the following files in the /var/lib/tftpboot/winos/<distro_name>/$OEM$/$1/TMP directory:

ls -l '/var/lib/tftpboot/winos/Win10_EN-x64/$OEM$/$1/TMP'
total 2972
-rwxr-xr-x. 1 root root 1177600 Sep  4  2008 libeay32.dll
-rwxr-xr-x. 1 root root 1008128 Mar 15  2008 libiconv2.dll
-rwxr-xr-x. 1 root root  103424 May  6  2005 libintl3.dll
-rwxr-xr-x. 1 root root  232960 Sep  4  2008 libssl32.dll
-rwxr-xr-x. 1 root root    4880 Oct 26  1999 sleep.exe
-rwxr-xr-x. 1 root root   52736 Oct 27  2013 todos.exe
-rwxr-xr-x. 1 root root  449024 Dec 31  2008 wget.exe

The win_wait_network_online snippet might look something like this:

set n=0

ping @@http_server@@ -n 3
set exit_code=%ERRORLEVEL%

IF %exit_code% EQU 0 GOTO wno_exit
set /a n=n+1
IF %n% lss 30 goto wno20
goto wno10

  • win.ks - Automatic Installation Template, which is specified for the Cobbler profile in cobbler profile add/edit --autoinstall=win.ks .. command.



set n=0

net use y: \\@@http_server@@\Public /user:install install
set exit_code=%ERRORLEVEL%

IF %exit_code% EQU 0 GOTO mount_z
set /a n=n+1
IF %n% lss 20 goto mount_y
goto mount_y

set n=0

net use z: \\@@http_server@@\winos /user:install install
set exit_code=%ERRORLEVEL%

IF %exit_code% EQU 0 GOTO mount_exit
set /a n=n+1
IF %n% lss 20 goto mount_z
goto mount_z

if exist %systemdrive%\TMP\stage.dat goto flag005
echo 0 > %systemdrive%\TMP\stage.dat


#if $distro_name in ( 'WinXp_EN-i386', 'Win2k3-Server_EN-x64' )
z:\Drivers\wsname.exe /N:$DNS /NOREBOOT
REM pause
#end if
echo Windows Registry Editor Version 5.00 > %systemdrive%\TMP\install.reg
echo [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce] >> %systemdrive%\TMP\install.reg
echo "DD"="C:\\TMP\\install.cmd" >> %systemdrive%\TMP\install.reg

#if $distro_name == 'Win2k3-Server_EN-x64'
start /wait z:\Win2K3-Server_EN-x64\cmpnents\r2\setup2.exe /q /a /sr
start /wait y:\Windows\Win2003\IE8-WindowsServer2003-x64-ENU.exe /passive /update-no /norestart
if %virt% equ NO REG IMPORT y:\Windows\Win2003\vm.reg
#end if
REG IMPORT %systemdrive%\TMP\install.reg
net use Y: /delete
net use Z: /delete
%systemdrive%\TMP\sleep.exe 10

for /f "tokens=*" %%i in (%systemdrive%\TMP\stage.dat) do set stage=%%i
echo 1 > %systemdrive%\TMP\stage.dat
REG IMPORT %systemdrive%\TMP\install.reg
if %stage% neq 0 goto flag010
net use Y: /delete
net use Z: /delete
shutdown -r -f -t 5

if %stage% gtr 1 goto flag020
echo 2 > %systemdrive%\TMP\stage.dat

#if $distro_name in ( 'WinXp_EN-i386', 'Win2k3-Server_EN-x64' )
#else if $distro_name in (  'Win7_EN-x64', 'Win8_EN-x64' )

< .. >

Title Cleaning Temp files
DEL "%systemroot%\*.bmp" >nul 2>&1
DEL "%systemroot%\Web\Wallpaper\*.jpg" >nul 2>&1
DEL "%systemroot%\system32\dllcache\*.scr" >nul 2>&1
DEL "%systemroot%\system32\*.scr" >nul 2>&1
DEL "%AllUsersProfile%\Start Menu\Windows Update.lnk" >nul 2>&1
DEL "%AllUsersProfile%\Start Menu\Set Program Access and Defaults.lnk" >nul 2>&1
DEL "%AllUsersProfile%\Start Menu\Windows Catalog.lnk" >nul 2>&1
DEL "%systemdrive%\Microsoft Office*.txt" >nul 2>&1
net user aspnet /delete >nul 2>&1
REM %systemdrive%\TMP\sleep.exe 60
net use Y: /delete
net use Z: /delete

shutdown -r -f -t 30
RD /S /Q %systemdrive%\DRIVERS\ >nul 2>&1
if not defined stage DEL /F /Q %systemdrive%\post_install.cmd
DEL /F /S /Q %systemdrive%\TMP\*.*
  • Add Windows to the network installation menu in the /etc/cobbler/boot_loader_conf/pxedefault.template file:
menu begin Windows
        label Win10_EN-x64
                MENU INDENT 5
                MENU LABEL Win10_EN-x64
                kernel /winos/Win10_EN-x64/win10a.0
        label  Win10-profile1
                MENU INDENT 5
                MENU LABEL  Win10-profile1
                kernel /winos/Win10_EN-x64/win10b.0
        label  Win10-profile2
                MENU INDENT 5
                MENU LABEL  Win10-profile2
                kernel /winos/Win10_EN-x64/win10c.0
        label Win2016-Server_EN-x64
                MENU INDENT 5
                MENU LABEL Win2016-Server_EN-x64
                kernel /winos/Win2016-Server_EN-x64/win6ra.0
< .. >
        label returntomain
                menu label Return to ^main menu.
                menu exit
menu end

Or create an iPXE boot menu

< .. >
kernel http://<http_server>/winos/wimboot
initrd --name bootx64.efi   http://<http_server>/winos/Win10_EN-x64/EFI/Boot/bootx64.efi bootx64.efi
initrd --name bcd           http://<http_server>/winos/Win10_EN-x64/boot/1Ea             bcd
initrd --name boot.sdi      http://<http_server>/winos/Win10_EN-x64/boot/boot.sdi        boot.sdi
initrd --name winpe.wim     http://<http_server>/winos/Win10_EN-x64/boot/winpe.wim       winpe.wim
< .. >

6.3.3. Final steps

  • Restart the services:
systemctl restart cobblerd
systemctl restart tftpd
systemctl restart smb
systemctl restart nmb
  • add distros:
cobbler distro add –name=Win10_EN-x64 \
--kernel=/var/lib/tftpboot/winos/Win10_EN-x64/pxeboot.n12 \
--initrd=/var/lib/tftpboot/winos/boot/boot.sdi \
--boot-loader=pxelinux \
--arch=x86_64 --breed=windows –os-version=10 \
  • and profiles:
cobbler profile add --name=Win10_EN-x64 --distro=Win10_EN-x64 --autoinstall=win.ks \
--kernel-options='pxeboot=win10a.0, bootmgr=boot1ea.exe, bcd=1Ea,winpe=winpe.wim, sif=autounattended.xml'

cobbler profile add --name=Win10-profile1 --parent=Win10_EN-x64 \
--kernel-options='pxeboot=win10b.0, bootmgr=boot1eb.exe, bcd=1Eb,winpe=winp1.wim, sif=autounattende1.xml'

cobbler profile add --name=Win10-profile2 --parent=Win10_EN-x64 \
--kernel-options='pxeboot=win10c.0, bootmgr=boot1ec.exe, bcd=1Ec,winpe=winp2.wim, sif=autounattende2.xml'
  • cobbler sync
  • Install Windows