fdtbus(4)

fdtbus4

Flattened device tree bus driver

Usage

options FDT

Overview

The fdtbus abstract bus driver is the primary connection and translation layer between fdt(4) hardware resources description and FreeBSD native newbus device drivers framework. For an embedded system fdtbus represents peripherals typically found on a highly integrated chip (system-on-chip).

The fdtbus driver provides generic, common infrastructure for all fdt(4) oriented device drivers, and its main responsibilities are the following:

  • Creating newbus children that reflect fdt(4) nodes in the flattened device tree.

  • Managing SYS_RES_IRQ resources.

  • Managing SYS_RES_MEMORY, SYS_RES_IOPORT resources.

Releases

34 releases since FreeBSD 9.0-RELEASE; the text changed 20 times.

  1. 9.0
  2. 9.1
  3. 9.2
  4. 9.3
  5. 10.0
  6. 10.1
  7. 10.2
  8. 10.3
  9. 10.4
  10. 11.0
  11. 11.1
  12. 11.2
  13. 11.3
  14. 11.4
  15. 12.0
  16. 12.1
  17. 12.2
  18. 12.3
  19. 12.4
  20. 13.0–13.2
  21. 13.3–16.0

Standards

IEEE Std 1275: IEEE Standard for Boot (Initialization Configuration) Firmware: Core Requirements and Practices (Open Firmware).

Power.org Standard for Embedded Power Architecture Platform Requirements (ePAPR).

History

The fdtbus support first appeared in FreeBSD 9.0.

Authors

The fdtbus support was developed by Semihalf under sponsorship from the FreeBSD Foundation. This manual page was written by Rafal Jaworowski.

From base 16.0-CURRENT-20261027-61c70dc16a79 in FreeBSD 16.0-CURRENT (2026-10-27). Parsed by carta from the page's mdoc source.