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UEFI Capsule Update for coreboot with EDK II


The project, UEFI Capsule Update for coreboot with EDK II, aims to improve the firmware update process by integrating UEFI capsule update methods into coreboot with EDK II open-source firmware frameworks. UEFI capsule update is an industry-standard approach widely supported by hardware vendors, providing a secure and reliable method for delivering firmware updates. By adopting UEFI capsule update methods, the project aims to simplify the update process and enhance the user experience, providing a more secure and reliable approach compared to complex flashrom-based updates, which are still common in the open-source firmware distributions based on coreboot. Due to security measures, OS-level access to firmware is intentionally restricted, which in turn makes it increasingly challenging to apply firmware updates from the operating system. This limitation poses difficulties in utilizing traditional flashrom-based methods for firmware updates. The expected outcomes of the project include enhanced firmware update capabilities, a simplified user experience, heightened security, and enhanced compatibility, all achieved by seamlessly integrating with fwupd, a popular firmware update management tool for Linux systems.

Involvement with projects or organisations relevant to this project

Relevant projects:

  • coreboot [1]
  • Dasharo compatible with MSI PRO Z690-A DDR4 (and the subsequent port for the
  • DDR5 variant) [2]
  • Dasharo compatible with Dell Optiplex [3]
  • EDKII [4]
  • Fwupd (LVFS) [5]
  • U-Boot [6]

3mdeb has been a licensed provider of quality coreboot consulting services since 2016. We are well-known in the open-source community for maintaining th firmware of the PC Engines APU series platform since 2016, delivering high-quality firmware releases each month and providing technical support on PC Engines and OPNSense forums. Our contribution to the coreboot project reaches (as of 26th of July 2023):

319 individual patches merged to the official coreboot repository 33481 lines of code added 41097 lines of code removed

Moreover, we constantly develop Dasharo, which is an open-source firmware distribution focusing on clean and simple code, long-term maintenance, transparent validation, privacy-respecting implementation, liberty for the owners, and trustworthiness for all. More details can be found here [7].

Project scope

Task 1. Enable Capsule Updates in coreboot

This task aims to enhance the coreboot framework by adding support for UEFI Capsule Update.

  • Enable memory access above 4GB

Modify coreboot to operate in 64-bit mode and enable access to memory above the 4GB limit.

  • Parse capsule location from UEFI variables in coreboot

Implement a mechanism for coreboot to identify the memory location of the capsule images from drivers to UEFI variables. This milestone ensures accurate retrieval of capsule images by coreboot.

  • Gather capsules into one region

Rewrite the existing capsule coalescing logic to consolidate all firmware update capsules into a single memory region.

  • Reserve memory containing capsules and pass it to the payload

Implement the necessary changes in coreboot to reserve the memory region containing the capsules. Pass this information to the UEFI payload using the Hand-Off Block (HOB) data structure.

  • Add SMI handler for flashing firmware updates

Implement a handler able of writing to SPI flash. Similar handler already exists, but it is limited to SMMSTORE region, used to implement secure UEFI variables. New handler would allow to overwrite whole BIOS image, so it must not be enabled unless a valid capsule update is present.

Task 2. Enable capsule updates in coreboot EDK II UEFI Payload

The UEFI payload integration task involves integrating the enhanced coreboot firmware with the UEFI system. Additionally, parsing the version reported by coreboot and incorporating it into the EFI System Resource Table (ESRT) ensures accurate tracking of system firmware updates. These integrations enhance firmware reliability, provide advanced update capabilities, and enable a seamless user experience.

  • Implement PlatformFlashAccessLib leveraging coreboot SMI handler

Create a library instance that enables flash access operations within the UEFI platform with the help of SMI handler implemented in coreboot.

  • Modify FDF/DSC files and capsule processing

Update the Firmware Descriptor (FDF) and Device Scope Configuration (DSC) files. Enable boot mode selection and invoke ProcessCapsules() at the necessary stages during the firmware update process.

  • Parse version reported by coreboot for ESRT

Extract coreboot version information and incorporate it into the EFI System Resource Table (ESRT) within UEFI, to reflect the updated firmware and prevent rolling back to earlier versions.

  • Develop process for building capsules from coreboot.rom

Establish a streamlined workflow to generate capsules containing the coreboot.rom image and automate the process where possible.

Task 3. Test the solution on a hardware

In this task, the UEFI Capsule Update will be tested on the hardware to ensure its proper functionality and compatibility.

  • Verify feature using test signing keys

Validate the CAPSULE_ENABLE feature using test signing keys before using product-specific signing keys.

  • OS block booting verification

Test a mechanism that prevents the operating system from booting until a reboot occurs after the firmware update process. The primary objective is to ensure that the system remains secure and stable after firmware updates are applied.

Task 4. Secure Firmware Signing

In this task the focus is on implementing secure firmware signing processes to ensure the integrity and authenticity of firmware updates. The use of OpenSSL utilities for generating signing keys enhances security, while the developed binary compilation procedure simplifies the signing process for end-users.

  • Generate signing keys using OpenSSL utilities

Utilize OpenSSL command line utilities to generate the necessary signing keys for the capsule update process.

  • Develop binary compilation without using a private key

This milestone involves creating a comprehensive procedure for users, outlining the process of signing binaries without the use of a private key, ensuring a consistent and efficient signing process.

  • End-user documentation

Create comprehensive documentation for end-users, including detailed instructions on how to perform firmware updates and utilize the provided features effectively.

Task 5. Enhanced Boot Process with vboot A/B Support

This task aims to establish a more secure, stable, and user-friendly firmware update process. The incorporation of the vboot A/B scheme will provide a reliable fallback in case of problematic updates, while the automated execution of the UX capsule will enhance the end-user experience during firmware updates.

  • Add support for the vboot A/B scheme

Enhance the firmware update mechanism to support the vboot A/B scheme, providing a fallback option in case of unstable updates.

  • Automate the creation and execution of the UX capsule

Use UX capsule to convey message to the user that the update is in progress. Because update takes significantly more time than normal boot, impatient user may think that the boot process is stuck and try to force a platform reboot, which in turn may end up with non-working platform.

Task 6. Test and release UEFI Capsule Update for coreboot and EDK II

Task 6 involves testing and release of firmware updates for both MSI PRO Z790-P and MSI PRO Z690-A DDR4/DDR5 platforms. The primary focus is to verify the successful update process, ensuring system stability and security after applying the new firmware update method.

  • Test and publish release for MSI PRO Z790-P

Verify the successful update process and ensure system stability and security after applying the new firmware update method.

  • Test and publish release for MSI PRO Z690-A DDR4/DDR5

Verify the successful update process and ensure system stability and security after applying the new firmware update method.

Task 7. Upstream of the UEFI Capsule Update for coreboot with EDK II in coreboot

The primary objective is to merge the UEFI Capsule Update functionality directly into the coreboot codebase, ensuring its availability as part of the coreboot project and expanding the firmware update capabilities for coreboot-supported systems.

The code implementing UEFI Capsule Update for coreboot with EDK II shall be upstreamed to the official coreboot repository at

Task 8. Upstream of the UEFI Capsule Update for coreboot with EDK II in EDK II

The goal is to ensure that the UEFI Capsule Update implementation becomes a part of the official codebase, contributing to the wider EDK II ecosystem and enhancing the firmware update capabilities for coreboot-supported systems.

The code implementing UEFI Capsule Update for coreboot with EDK II shall be upstreamed to the official EDK II repository at

Compare your own project with existing or historical efforts

3mdeb's embedded systems developers are experienced engineers accustomed to firmware development on desktops. There are a few successfully enabled coreboot supported Dell machines that were enabled by 3mdeb and other platforms based on Intel FSP. By leveraging our knowledge and experience from the ESRT project, which plays a vital role within the operating system to initiate capsule updates at the system level, we bring valuable insights and advancements to the firmware update process. Through our contributions, we aim to promote open-source firmware adoption and facilitate a more robust and secure firmware update process, benefiting open-source firmware community and and ensuring a user-friendly and efficient firmware update experience for end-users.

Significant technical challenges you expect to solve during the project

The coreboot and EDK II firmware frameworks need to be modified to support UEFI capsule update methods. This integration requires understanding and implementing the UEFI specification, especially the EFI_FIRMWARE_MANAGEMENT_PROTOCOL, FMP capsule format, and EFI System Resource Table (ESRT). Adapting coreboot and EDK II to support these mechanisms will involve extensive code changes and ensuring compatibility with the UEFI standard. Solving these challenges will involve significant code modifications, rigorous testing, and an active collaboration with the coreboot and EDK II communities to ensure successful integration and smooth functionality.

Ecosystem of the project

Although 3mdeb will be responsible for the whole implementation and testing, anyone is also welcome to test, develop code, and report issues after the results will be published. For the project to be successful, the outcomes should be included in the upstream coreboot and edk2 projects for the benefit of the wider community. That is why we expect high level of engagement with communities of both of this projects at each stage of the project, to make sure the proposed solution can be accepted upstream.


Further reviews and suggestions are welcome. You can do it in two ways:

  • using Giscus on the bottom of this page
  • contributing to this repository directly via Pull Request