Raspberry Pi 4 Model A and Zero 3 W surface in Linux device tree merge

A merged pull request in Raspberry Pi's forked Linux kernel repository has revealed technical details for two upcoming single-board computers that the company has not formally announced: the Raspberry Pi 4 Model A and Raspberry Pi Zero 3 W. The changes, signed off by Raspberry Pi engineer Marta Momotko, add device tree overlays across five files that define hardware support for both boards. This marks the first Model A variant since the Raspberry Pi 3 Model A+, as the Pi 4 launched only in Model B form and the Pi 5 dropped the suffix entirely.

Both new boards will use the Broadcom BCM2711 system-on-chip with four Arm Cortex-A72 cores at up to 1.8GHz and VideoCore VI graphics, rather than the BCM2712 found in the Pi 5. The device trees indicate each board will carry a BCM283x-family Bluetooth and Wi-Fi chip, a physical power button, the standard 40-pin GPIO header, and only a single HDMI output—with HDMI1 explicitly disabled in the overlay configuration. The Pi Zero 3 W represents a generational step up for the Zero family, though the RAM configuration remains unspecified.

Device tree details and hardware configuration

• SoC selection: Both boards use the Broadcom BCM2711 (four Cortex-A72 cores, VideoCore VI GPU) rather than the Pi 5's BCM2712, representing a deliberate platform segmentation for cost-sensitive or compact form factors.
• Wireless connectivity: A Broadcom BCM283x-family combo chip provides integrated Bluetooth and Wi-Fi on both models, eliminating the need for external wireless modules or the USB-based wireless implementations of earlier Zero boards.
• HDMI limitation: The device tree explicitly sets HDMI1 to "permanently disable," confirming only one HDMI output per board—half the Pi 4 Model B's dual-output capability—consistent with the reduced footprint and cost targets of Model A and Zero variants.
• GPIO retention: Both boards preserve the 40-pin GPIO header, maintaining hardware compatibility with existing HATs and accessories despite the smaller form factors.
• Power button support: The device tree includes a physical power button, a feature that has become standard on newer Pi designs but was absent from original Zero and early Model A boards.

Why it matters

The return of the Model A form factor fills a gap in Raspberry Pi's lineup for cost-constrained and space-constrained embedded applications that do not require the full I/O complement of a Model B. For the Zero family, moving to the BCM2711 platform brings 64-bit Arm capability and substantially more compute headroom while retaining the compact footprint, though developers will need to account for the RAM limitations that have historically defined the Zero line. Linux distribution maintainers and embedded tooling projects should prepare device tree overlays and kernel configurations for the BCM2711-based variants, as these boards will likely see significant adoption in IoT, portable, and educational deployments where the Pi 5's performance and cost would be excessive.