Install Libreboot on Dell OptiPlex 3040/3050 Micro

Return to index

Specifications
Manufacturer	Dell
Name	OptiPlex 3040/3050 Micro
Released	2015/2017
Chipset	Intel H110/B250
CPU	LGA 1151; Intel 6-9th gen. 35W TDP
Graphics	Intel HD 510 -> UHD 630
Memory	16GB DDR3L SODIMMs (2x8GB) 3040
Memory	32GB DDR4 SODIMMs (2x16GB) 3050
Architecture	x86-64-v3 (+ older)
Original boot firmware	Dell UEFI firmware
Intel ME/AMD PSP	Present. Disabled with me_cleaner.
Flash chip	SOIC-8 16MiB

W+: Works without vendor firmware; 
N: Doesn't work; 
W*: Works with vendor firmware; 
U: Untested; 
P+: Partially works; 
P*: Partially works with vendor firmware
?: UNKNOWN AT THIS TIME

Features
Internal flashing with original boot firmware	W*
Display (if Intel GPU)	W+
Audio	W+
RAM Init	W*

Download from release

If you’re using a release ROM, please ensure that you’ve inserted extra firmware required refer to the guide for that (, failure to adhere to this advice will result in a bricked machine):

• Intel ME (vendor blob)
• Intel FSP (vendor blob)

Latest Release is advised, scroll below for more.

Build from source

For the older one with DDR3L 1.35V only:

./mk -b coreboot dell_optiplex_3040_micro_16mb

For the newer one with DDR4 with M.2 PCIe:

./mk -b coreboot dell_optiplex_3050_micro_16mb

Short the service jumper. It’s near the RAM, under where the HDD goes (click the photos shown above). Just put a short on it when booting, and all flash protection is disabled; the factory firmware write might EFI variables to flash during shutdown sequence, so you should pull the plug to shut it down (remove the power by pulling the plug) after flashprog says VERIFIED.

After the jumper set, follow the guide to backup and flash.

The side cover comes off easily, and you can find the flash ICs next to the RAM. Simply remove the screw at the back. The top panel then slides forward, and you can remove the SSD caddy; from then on, the flash is accessible.

Observe the following photo of the flash (SOIC-8):

REMOVE all power sources and connectors from the machine, before doing this. This is to prevent short circuiting and power surges while flashing.

Check the hw-flashing guide before moving onto the next step below.

Flash it: (With rpi-pico as an example, edit the line if needed.)

flashprog -p serprog:dev=/dev/ttyACM0,spispeed=16M -w filename.rom

This has a Realtek NIC inside, instead of Intel, so the MAC address will not change. This means: there is no GbE region in the flash.

You can still use something like macchanger to change your MAC address from Linux if you want to.

This is great, because that’s one less complexity to deal with during installation.

Mate Kukri’s deguard utility disables the Intel Boot Guard on this machine. Libreboot uses this by default, along with me_cleaner to provide a neutered ME setup; unlike on other platforms, arbitrary code execution is also possible inside the ME on this motherboard, giving it much higher potential for software freedom in the future.

Of particular interest, this board uses the deguard software, to disable Intel Boot Guard. This means also that the ME firmware no longer has functional cryptographic signature checking for most of it; you can theoretically run whatever you want on the ME coprocessor.

Libre ME doesn’t exist yet, but it’s now possible. Example use-case for a libre ME could include, for example, running an out-of-bound packet filter on a secure network (with flash write protection, making it invincible to any OS-based software attacks).

• A pin mod is needed.

Guide for mod

Do not insert regular ddr3 ram modules, as the 1.5V =/< voltages could easily fry the processor’s integrated memory controller, so use ddr3l ones only with 1.35V rating.

This machine basically works flawlessly, as of the Libreboot 20241206 release. All the initial bugs were fixed, e.g. PWM fan control works now. A very nice machine, and inexpensive, plus very easy to set up for the average user. The ideal Libreboot desktop.

HMDI audio

Works, but you have to select it in your audio server e.g. pipewire. The pavucontrol utility in Linux (with pipewire) lets you have a lot of control over audio I/O. Libreboot patches the board to add a verb, so headphones should work.

Selection of audio devices and outputs is a bit idiosyncratic on this board. Just play with pavucontrol for your setup and it should work fine.

VGA output

All 3050 Micros have one Displayport and one HDMI output. These work very well, but a few models have a VGA output via add-on board.

The VGA output is actually a digital to analog converter internally, on an expansion board mounted to the rear chassis. In testing, this worked fine with the Libreboot payloads e.g. SeaBIOS and GRUB, but then Linux wouldn’t show any output to the screen.

This should be investigated/fixed, but for now, you might use your own digital to analog converter. For example, Displayport to VGA converters are very cheap and easy to find.

Linux can be hit or miss with these adapters, as can libgfxinit (when showing payloads), so you just have to try a bunch of adapters until one works.

The onboard DisplayPort and HDMI outputs work fine. It’s just the VGA port that can be a bit flaky depending on your operating system.

Warning regarding NVMe SSDs for 3050

Please use at least Libreboot 20241206 revision 3 or higher. This is because older revisions contained a bug, where the NVMe SSD would be replugged under Linux, randomly, leading to data loss.

This is fixed in 20241206 rev3 or higher, by disabling PCI-E hotplug on the NVMe SSD slot.

See: Libreboot 20241206 release

Power-on after power failure

Older Libreboot revisions made this machine always turn on, when plugging in a power supply (charger brick), if a previous power loss was observed. This is because coreboot sets a special register in the PMC that configures such behaviour, but it was hardcoded to always-on. This is undesirable for most people, so Libreboot 20241206 revision 8 and newer releases contain the following modification:

https://codeberg.org/libreboot/lbmk/commit/09a01477df67e3ddc36e11123c537332d7813c50

If you wish to modify this behaviour again, you could modify the patch referenced there; the actual location of the .patch file may change over time, so you can basically just modify the coreboot source file at src/soc/intel/common/block/pmc/pmclib.c (for the coreboot tree under src/coreboot/ in lbmk, pertaining to your board, which can be determined by reading the tree variable in your board’s target.cfg file within lbmk).

Use the patch as reference, to modify the coreboot behaviour as you wish, and re-compile from source.

TPM disabled

The TPM is disabled on this device, to prevent hanging/boot delay in SeaBIOS, due to buggy TPM drivers there.

Legacy 8254 timer

Legacy 8254 timer enabled in coreboot, to prevent SeaBIOS from hanging.

HyperThreading on 3050 Micro

NOTE: The 3050 Micro is available in different CPU configurations. Before considering to enable HyperThreading support, make sure it is supported by the CPU of your 3050 Micro.

Also called SMT. This is a feature where you get 2 threads on a single core. It can improve performance in some workloads, but is actually a performance liability in others, depending on your OS kernel/scheduler and the actual workload.

It is a security liability, due to the Spectre/Meltdown attacks, so we recommend turning it off, at the very least from your running operating system. On this platform, you can easily turn it off from coreboot.

Libreboot disables HyperThreading by default, from Libreboot 20241206 rev8 onward, on this board. To turn it back on, please build from source and before running the build command, do this:

./mk -m coreboot dell_optiplex_3050_micro_16mb

In the menu that appears, go Chipset -> Enable Hyper-Threading and turn it on. Then exit from the menu, saving the config where prompted. You will see this menu twice, because there are two configs for each of these boards.

SMT is rarely of benefit in practice, but can be useful in some circumstances. For example; - Games, with proper smt utilization. - Compiling a large codebase from source that takes hours, SMT increases the building speed by about 15 percent; for example, a 3 hour build job might take about 2 hours and 40 minutes instead.

SPDX-License-Identifier: GFDL-1.3-or-later

Markdown file for this page: https://libreboot.org/docs/install/dell3050.md

Site map

This HTML page was generated by the Libreboot Static Site Generator.