[TUHS] the device tree, hardware, and kernels.

[segaloco via TUHS]

On Monday, April 6th, 2026 at 14:02, ron minnich via TUHS <tuhs at tuhs.org> wrote:

> The reason I ask: somehow, the device tree is now something that gets
> packaged with the kernel, which seems a violation of its purpose.

Somewhat, you get a DTB in your boot partition (usually FAT to appease UEFI these days afaik) but this boot partition may be loading a kernel directly on some systems, dropping in a uboot loader on others, but the DTB gets loaded usually pretty darn early, in my experience prior to jumping into the actual kernel bootstrap, much like how PCs dump a bunch of information in a know memory location ala BIOS for the bootstrap to inspect.  Granted the sources that become DTBs I see distributed as DTSs with i.e. the Linux kernel.  I don't know DTB holistically, if there is some upstream that feeds the penguins or if they run the show on their DTB stuff.

> The Image struct for arm and riscv usually has a device tree
> at the front.

This is not my experience on Raspberry Pi and RISC-V distros of Linux and FreeBSD I've used.  They all had a directory of DTBs in their boot partition that were selected from by whatever bootloader stage straps in the kernel, initramfs, etc.  The kernel Image file, initrd, and dtb are transferred as separate BLOBs, so could exist independently of one another.

- Matt G.