Announcing the coreboot release 25.06

coreboot 25.06

The coreboot project is pleased to announce the release of coreboot 25.06, another milestone in our work promoting the use of open-source firmware. This release incorporates almost 900 commits from more than 120 contributors, including 28 first time contributors. It brings enhanced boot splash screen capabilities, improved build tooling support, and expanded wireless power management features. Along with these headline improvements, we’ve delivered numerous stability enhancements and infrastructure updates that strengthen coreboot’s foundation across all supported platforms.

As always, the coreboot project extends our appreciation to everyone who contributed to this release. From seasoned developers submitting complex patches to newcomers providing valuable feedback and testing, your collective efforts make each coreboot release better than the last. The continued growth of our contributor base demonstrates the strength and vitality of the open firmware community.

The next coreboot release, 25.09, is scheduled for the end of September 2025.

Project Updates

  • In the past several months, the coreboot project has worked to help groups who can’t always push their code directly to the main development branch, offering to host separate branches and separate repositories for this work. A document wirh more details will be uploaded shortly.
  • The coreboot project has had bi-weekly leadership meetings where project issues are discussed for a number of years, but they’ve always been at a time which makes it difficult for people in Asia to attend. We are going to start a second meeting on the same day as the existing meeting, but at a better time for Asia. Check the coreboot calendar for details: https://www.coreboot.org/calendar.html
  • After many years, the coreboot mascot finally has a name: Blitz, the corebunny. This is a reference to the boot speed which can be achieved through using the coreboot project, and reflects the design intent of the logo, a European Brown Hare, which is very adaptable and runs at speeds of up to 72 km/h (45 mph).

Significant or interesting changes

{lib, drivers/intel}: Enhanced boot splash screen framework

A comprehensive overhaul of the boot splash screen infrastructure introduces support for multiple logo types and improved rendering capabilities. The new framework adds bmp_load_logo_by_type() function (be5609bdaf, 4373eea5d8) to enable platform-specific logo selection, while introducing splash screen footer support for better brand presentation.

The enhanced system includes horizontal logo alignment controls (dfeaead9f2) and configurable footer bottom margins (97f92d5c69), providing OEMs with greater flexibility in customizing the boot experience. Additionally, the framework now tracks splash screen rendering completion (4c446751c6) through commonlib, enabling better coordination between firmware phases and payload handoff.

Low-battery mode detection has been integrated into the splash screen system, automatically suppressing OEM footers when battery levels are critical (d309a9dfa8). This ensures essential power information takes precedence during low-power boot scenarios, improving user experience on battery-powered devices.

util/cbfstool: Multi-ELF support for advanced payload configurations

The cbfstool utility has been extended with multi-ELF support (0dcea61e7c), enabling more sophisticated payload packaging and deployment scenarios. This enhancement allows firmware developers to bundle multiple ELF binaries within a single CBFS entry, facilitating complex boot scenarios where multiple components need to be loaded simultaneously.

The implementation provides better flexibility for hypervisor deployments, multi-stage bootloaders, and security-enhanced boot configurations where isolation between components is critical. This feature particularly benefits platforms requiring trusted execution environments or compartmentalized boot processes.

drivers/wifi/generic: Advanced Power Reduction Features

Implementation of both Wi-Fi and Bluetooth Power Reduction Request (PRR) DSM functions (d92b6163e7, efa24540b0) significantly improves power management capabilities for wireless subsystems. These ACPI methods enable operating systems to request aggressive power savings during idle periods or when specific wireless functions are not required.

The PRR implementation follows Microsoft’s Modern Standby specifications, allowing Windows and other operating systems to achieve deeper sleep states by coordinating with wireless hardware. This results in improved battery life on mobile platforms and better thermal management on passively cooled systems.

security/vboot: Enhanced boot phase integrity management

The vboot subsystem now includes CMOS data backup during later boot phases (bf330f2dd0), providing additional protection against unexpected power events during firmware execution. This change ensures that critical configuration data remains consistent even if power is lost during complex initialization sequences.

A new VBOOT_EC_SYNC_ESOL Kconfig option (ac4503d0dd) has been introduced to provide finer control over Embedded Controller synchronization behavior. This allows platforms to optimize EC update procedures based on their specific hardware requirements and boot time constraints.

Additionally, MRC cache measurements as runtime data (b5581d556b) have been integrated into the trusted boot chain, ensuring that memory training data integrity is verified as part of the overall system attestation process.

Build system improvements: GCC 15 compatibility and toolchain updates

Comprehensive work has been completed to ensure compatibility with GCC 15, including fixes for the new -Werror=unterminated-string-initialization warning (73cc8a413a). The build system now properly handles modern compiler requirements while maintaining backward compatibility with existing toolchain versions.

The crossgcc build system has been enhanced with RISC-V ISA specification support (89e4fff2d3), enabling more precise control over RISC-V target architectures. This improvement allows developers to build optimized firmware for specific RISC-V implementations while ensuring compatibility across the diverse RISC-V ecosystem.

Submodule management has been significantly improved with better path handling (c4eb645a0b) and enhanced logging (f2310ab35e), making it easier for developers to track third-party component updates and maintain consistent build environments.

Enhanced SoC support: Emerald Rapids and Panther Lake

Support for Intel’s 5th Generation Xeon Scalable Processors (Emerald Rapids) has been added (9d878fc6c0), bringing coreboot to Intel’s latest server and workstation platforms. This implementation includes support for the expanded feature set and improved power management capabilities of the Emerald Rapids architecture.

Panther Lake support continues to evolve with new SKU additions (b879342fe6) and VR Fast Vmode threshold optimizations (e58883aace). The refactored SoC configuration (cf5696834b) provides a cleaner foundation for supporting the full range of Panther Lake variants as they become available.

Documentation: Clarification of contributor responsibilities and AI tool usage

A significant policy clarification has been added to the project documentation (9ddc9cbfc9) addressing contributor responsibilities, particularly in the context of modern development practices including the use of AI-assisted tools. This addition reinforces that submitters bear full responsibility for ensuring their contributions meet coreboot’s quality standards and comply with all applicable licensing requirements, regardless of how the code was generated or authored.

The new documentation explicitly states that contributors must have all necessary rights to submit their work under coreboot’s licenses, and that violations of third-party rights will result in code removal or replacement. This policy applies universally, encompassing contributions created through various means including generative AI tooling, ensuring the project maintains clear legal standing and quality expectations.

This clarification provides important guidance to the growing coreboot community as development practices evolve, establishing clear expectations while allowing contributors the flexibility to use whatever tools help them create high-quality firmware code.

Additional coreboot changes

  • Exposed ALWAYS_ALLOW_ABOVE_4G_ALLOCATION in Kconfig for x86 to fix Resizable BAR support on modern GPUs.
  • Enhanced PCI support with SR-IOV Virtual Function BAR resource assignment capabilities
  • Improved SPI driver support for forced 4-byte address mode operation via 0xB7 command sequences
  • Numerous MediaTek MT8189 and MT8196 platform enhancements including eDP, DDP, and AUXADC driver improvements
  • Enhanced memory initialization support across multiple Intel platforms with improved timing and reliability
  • Expanded superio support with addition of Fintek f81966d controller
  • Improved ELOG handling for later boot phase operations
  • Enhanced SMMSTORE driver with 64-bit MMIO address support
  • Comprehensive timing infrastructure improvements with early chip initialization timestamps
  • Libpayload updates focused on ARM64 DMA and MMU fixes, build system improvements, and support for large USB mass storage devices.
  • Add documentation on devicetree, sconfig, cbmem and device operations.
  • Contributor guides updated with new commit message policy, Gerrit instructions, and collaboration details.

Changes to external resources

Toolchain updates

  • Fix GMP build on GCC 15
  • Add a RISCV_ISA_SPEC variable to the toolchain build script to allow for specifying the RISC-V ISA version.

Git submodule pointers

  • arm-trusted-firmware: Update from commit id e5a1f4abee to 9109143417 (523 commits)
  • fsp: Update from commit id 86c9111639 to cc36ae2b57 (9 commits)
  • intel-microcode: Update from commit id 8a62de41c0 to eeb93b7a81 (1 commit)

External payloads

  • edk2: Update default branch for MrChromebox repo to 2025-02

Platform Updates

Added mainboards:

  • ASUS H61M-A/USB3
  • CWWK CW-ADL-4L-V1.0
  • CWWK CW-ADLNTB-1C2L-V3.0
  • Google Anakin
  • Google Baze
  • Google Bluey
  • Google Brox RTK EC
  • Google Epic
  • Google Fatcat4ES
  • Google Fatcatite4ES
  • Google Fatcatnuvo4ES
  • Google Felino4ES
  • Google Kaladin
  • Google Kinmen
  • Google Obiwan
  • Google Ocelot4ES
  • Google Ocelotite
  • Google Ocelotite4ES
  • Google Ocelotmchp
  • Google Ocelotmchp4ES
  • Google Pujjocento
  • Google Pujjolo
  • Google Quenbi
  • Google Yoda
  • Intel Google Chrome EC
  • MiTAC Computing R520G6SB
  • MiTAC Computing SC513G6
  • NovaCustom V540TNx (14″)
  • NovaCustom V560TNx (16″)
  • Siemens MC RPL1
  • Star Labs Byte Mk III (N355)
  • System76 darp11
  • System76 lemp13

Updated SoCs

  • Added qualcomm/x1p42100

Statistics from the 25.03 to the 25.06 release

  • Total Commits: 882
  • Average Commits per day: 9.85
  • Total lines added: 73906
  • Average lines added per commit: 83.79
  • Number of patches adding more than 100 lines: 85
  • Average lines added per small commit: 40.39
  • Total lines removed: 15766
  • Average lines removed per commit: 17.88
  • Total difference between added and removed: 58140
  • Total authors: 128
  • New authors: 34