ARCH: Device Tree Blob Parser

Currently (as of Feb 11, 2024) the OS/Kernel setup is done statically; or in other words: everything is hard coded. There is no device discovery OR enumeration OR drivers.

Each day, I'm moving closer into the peripherals, devices and I/O territory. Before I can fully commit myself, I should implement a device discovery & driver matching system. To do that, naturally, I need a parser for a Device Tree Blobs.

Device Tree is a specification and has two important aspects:

Device Tree Structure (human-readable)
Device Tree Blob (binary-blob)

QEMU can dump the *.dtb file via the -machine dumpdtb=<out_file>.dtb CLI option. It can be useful when debugging.

QEMU automatically loads the *.dtb into main memory. The following specifies it's base address and related info:

/* Device Tree Blob (DTB) */
#define DTB_START       0x40000000
#define DTB_SIZE        0x00100000      /* 1 MiB */
#define DTB_END         (DTB_START + DTB_SIZE)

Good luck working on this! There are lots of good resources out there; I'm sure they will be helpful. ☆

TunaCici / WesterOS

ARCH: Device Tree Blob Parser #4