Date: Sat, 25 Apr 2026 22:44:02 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 294793] ofw(4) manpage Message-ID: <bug-294793-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=294793 Bug ID: 294793 Summary: ofw(4) manpage Product: Documentation Version: Latest Hardware: Any OS: Any Status: New Severity: Affects Many People Priority: --- Component: Manual Pages Assignee: bugs@FreeBSD.org Reporter: b1nc0d3x@gmail.com CC: doc@FreeBSD.org Attachment #270120 text/plain mime type: Created attachment 270120 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=270120&action=edit Manpage for ofw(4) Summary: ofw(4) manual page ========================== What ofw(4) documents ---------------------- ofw(4) documents the ofwbus driver — the Open Firmware pseudo-bus that sits directly under nexus(4) and enumerates top-level devices from the Open Firmware device tree, attaching them as children in the newbus(9) hierarchy. The page covers: - What Open Firmware is and how the device tree is structured (IEEE Std 1275-1994) - How ofwbus iterates the OF root node and instantiates newbus devices - The four supported OFW backend implementations: ofw_std Standard direct-call interface (e.g. 32-bit PowerPC) ofw_real Real-mode interface (e.g. 64-bit PowerPC) ofw_32bit 32-bit ABI compatibility interface ofw_fdt Flattened Device Tree backend (ARM, ARM64, RISC-V) - How the backend is selected at boot via OF_install()/OF_init() - The /dev/openfirm userspace interface (cross-referenced to openfirm(4)) - Pointers to ofwdump(8) for command-line device tree inspection Why it was missing ------------------- The FreeBSD src tree already has closely related pages: openfirm(4) Documents the /dev/openfirm character device and its ioctl interface — the userspace side of OFW. simplebus(4) Documents the ePAPR simple-bus driver that sits under ofwbus on FDT-based systems. fdt(4) Documents the Flattened Device Tree subsystem. ofw_console(4) Documents the Open Firmware fallback console (powerpc). However, none of these explain the ofwbus driver itself — the component that actually bridges Open Firmware to newbus and makes device enumeration possible on PowerPC, ARM, ARM64, and RISC-V. Both ofwdump(8) and simplebus(4) cross-reference openfirm(4) for background, but there was no page describing the bus driver that underpins the entire OFW subsystem. ofw(4) fills that gap. -- You are receiving this mail because: You are the assignee for the bug.home | help
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