How to bring up the Linux Kernel on a new platform

Posted by WerWolv 5 days ago

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Comments

Comment by Neywiny 1 day ago

I've done this for a cortex-m in qemu (meaning I wrote the chip and peripheral emulation code too for the timer, uart, sd controller with dma, and rcc). But I used buildroot. So much easier to keep track of everything and it's very easy to start with (unlike yocto). I recommend taking a look at buildroot.

You also don't need an MMU to run Linux. Just helps compatibility.

Good work

Comment by csdreamer7 5 days ago

Excellent post. Your file format RE looks like an additional one to add to the reading queue as well: https://werwolv.net/posts/file_format_reverse_engineering/

Comment by elevation 5 days ago

Great post, so neat to see it running in the browser! One question: why not thin the config a little? USB, SOUND, VGA, etc. are all slowing down the boot but don't have hardware to control.

Comment by WerWolv 5 days ago

This is a valid point a friend brought up as well. There's no reason all of this is enabled except for keeping the config simple. I only recently learned about `make tinyconfig` though which should let you creating a absolutely minimal config to start off of. I might add that as a note at the end

Comment by elevation 4 days ago

This complicated project was well executed, and I enjoyed it. I'm sorry your post wasn't more popular, I hope you won't be discouraged from sharing your adventures in the future!

Comment by hactually 18 hours ago

really enjoyed this - great to see modern C++ as well, we were all on Assembly and C when I had to do this on a Freescale/iMX chipset for a wireless router!

So good though taking a reference design, re-laying it out with new modules and then bringing it to life with a scope and a datasheet.

I can only imagine how much will have changed with LLMs being able to be read and have a harness to do the hard work for you!

Comment by devhunt-org 21 hours ago

What tends to be the biggest surprise when bringing Linux up on completely new hardware?

Comment by WerWolv 20 hours ago

It tends to be vendor drivers / vendor patches. Getting frustrated that my changes aren't applied just to see that the vendor decided to hardcode a field or dynamically patch the device tree in undocumented ways is what usually gets me