So you've just received a brand-new secondhand one of these things off Ebay, what do we need to do to it before use?

<<TableOfContents>>

= BIOS/UEFI settings =

== Getting in there ==

 * Mash F12 during POST to get the one-time boot target menu, you can access the BIOS/UEFI from there
 * If you get stuck in Windows because the keyboard wasn't detected fast enough, you can get to the desktop and then:
  * Hit the Windows key, type "UEFI", then select Change Advanced Start-up Options
  * Restart Now with the Advanced Startup button
  * Then from ''that'' boot menu go to Troubleshoot, Advanced Options, UEFI Firmware Settings, Restart

== Update the BIOS to the latest version ==

 * Use this guide: https://www.dell.com/support/kbdoc/en-au/000131486/update-the-dell-bios-in-a-linux-or-ubuntu-environment#updatebios2015
 * Despite the usual Dell docs saying you need to make a DOS boot disk and run the flash updater app from there, it turns out that the BIOS Flash Update target (also on the one-time boot menu) can read the `9020MA19.exe` file from a FAT32 filesystem on a USB stick just fine
 * Not sure if this only works in UEFI mode or not, but I kinda don't care because we ''want'' to be in UEFI mode
 * This applies to systems made from 2015 or later
 * The latest BIOS update for the Optiplex 9020M (as of 2023-04-10) is version A19, released 2019-07-19

== Grab the MAC address ==

Get the LOM MAC Address from Settings, General, System Info

You'll need this later when configuring PXE booting.

== Change BIOS/UEFI settings ==

The first thing you want to do is set it to full UEFI mode, no legacy here.

Then all these settings:
 * General
  * Boot Sequence
   * Select UEFI boot list
  * Advanced Boot Options
   * Disable Legacy OPROMs
  * UEFI Boot Path Security
   * Set to Never
  * Date/Time
   * Set clock to approx correct for UTC time
 * System Configuration
  * Integrated NIC
   * Enable UEFI Network Stack
   * Enabled w/ PXE
  * SATA Operation
   * AHCI
  * SMART Reporting
   * Disabled, we don't need it
  * Audio
   * Disable all audio, we don't need it
 * Security
  * TPM Security
   * Check everything except Clear
   * Activated
  * CPU XD support
   * Enabled
 * Secure Boot
  * Secure Boot Enable
   * Disabled
 * Performance
  * Multi-core support: All
  * Speedstep: Enabled
  * C-states: Enabled
  * Limit CPUID: Disabled
  * Turboboost: Enabled
 * Power Management
  * AC Recovery: Power On
  * Deep Sleep Control: Disabled
  * USB Wake Support: Enable USB wake from Standby
  * Wake on LAN/WLAN: LAN with PXE Boot
  * Block Sleep: Enable blocking of sleep
 * POST Behaviour
  * Keyboard Errors: Disable error detection
 * Virtualisation support
  * Enable VT
  * Enable VT-d
  * Enable Trusted Execution

Reboot and go back in again.

 * Boot only from IPv4 with NIC (PXE boot) 


= Prepare for PXE booting =

 1. Choose an IP address, the DHCP server will be used to configure the server when it comes up
 1. Choose a name, and go assign the name to address mapping in the DNS zone
 1. Record the allocation in the spreadsheet: https://docs.google.com/spreadsheets/d/1bUR4y21wuCVRCpQcBbP85wGAWELrVjo2_tNJ7la495A/edit#gid=0
 1. Configure the DHCP server with the static address reservation
  * In Mikrotik Winbox it's in IP -> DHCP Server -> Leases. You can open an existing static lease and Copy it. Make sure to edit the:
   * IP
   * Name
   * MAC address
   * Comment
  * In Mikrotik CLI it'd be something like this {{{
[furinkan@helian] /ip/dhcp-server/lease> add address=192.168.1.256 mac-address=02-99-88-77-66-55 server="dhcp general" comment=persica42
}}}
  * If using dnsmasq in Pihole we add a custom config file like `/etc/dnsmasq.d/02-pihole-dhcp-persica-cluster.conf` {{{
dhcp-host=02:99:88:77:66:55,set:persica,192.168.1.256,persica42,5m
# one dhcp-host line per host
dhcp-boot=tag:persica,grub/grubx64.efi,illustrious.thighhighs.top,192.168.1.12
}}} Note that things are a bit different here, we specify boot options per-host rather than at a subnet level like on Mikrotik
   * Run `pihole restartdns` after making changes

You should now be able to PXE boot the box. It'll get an address from DHCP, then hit the next-server for PXE executable which is `grubx64.efi`

Grub will download its menu from the TFTP server via baked-in path, which defines the kernel and initrd to download and execute. That's typically a Linux kernel, with cmdline options to start a kickstarted install. Kickstart will download its `kickstart.cfg` then the magic happens.

Now go put the right bits in the right places, you'll need a kernel and initrd at a minimum, then for auto installs you need a kickstart config (or Debian equivalent): [[PxeBooting#Putting_the_right_bits_in_the_right_places]]