Hacker News new | ask | show | jobs
by MisterTea 1248 days ago
Where is the CPU hardware manual that tells me the CPU's memory map and registers?

This is why so much hardware ends up in landfills. No thanks to undocumented junk.

1 comments

The CPU itself (Core Complex, including cache, irq controller, etc) is documented by SiFive:

https://www.sifive.com/cores/u74-mc

Unfortunately there appears to be no detailed documentation at all (unless you count a pile of Linux and bootloader patches, which I don't) for the peripherals, etc, outside of the core complex on the SoC:

https://doc-en.rvspace.org/Doc_Center/jh7110.html

> unless you count a pile of Linux and bootloader patches, which I don't

This is what drives me crazy. Vendor claims "open source" which means an outdated linux image and the source code is wrapped up inside of a megalith build monstrosity like penguintronix or yocto. Utter junk these things are.

OpenSBI patches are already upstream, and u-boot being reviewed for merging.

It is not anywhere as bad as you're picturing it.

> It is not anywhere as bad as you're picturing it.

It is If I want to bootstrap a kernel that isn't Linux.