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--- marcelmoolenaar:embedding_freebsd [2006/05/16 22:34] – WarnerLosh
+++ marcelmoolenaar:embedding_freebsd [2021/03/28 06:15] (current) – Add CategoryStale KubilayKocak
@@ Line 1: / Line 1: @@
-Describe Embedding %%FreeBSD%% here.
+===== Embedding FreeBSD =====
+==== Device description ====
+Definition: a flexible/generic mechanism for describing a single device (aka package).
+  * A device description has some type (could be class with sub-classes), used to match drivers to devices (akin to PCI).
+  * Contains a device's resources (I/O, interrupt, etc)
+  * Contains attributes
+  * Can contain "hints" to the OS for purposes of wiring devices down to drivers and unit numbers.
+==== Device tree ====
+Definition: a collection of device descriptions organized in a hierarchical structure.
+  * Can be partial; sub-trees that can be mapped/rooted at runtime.
+==== Implementation ====
+  * Textual representation. At first, the kernel will parse and translate to make it easier to 1) compile-in, 2) load as module, and 3) manually enter while booting.
+  * Bus driver that takes a device tree, parses it and creates the appropriate newbus hierarchy, followed by the standard probe and attach.
+----
+{{tag>Stale}}