Kernel 101 – Let’s write a Kernel • Hacker News Board

Re: Kernel 101 – Let’s write a Kernel

#101

Post by exDM69 » Wed, Apr 16, 2014, 7:00 AM UTC

TallGuyShort wrote: post #92

e12e wrote: post #87

Earlier quoted context omitted.

This makes me really sad. 32bit mode x86 assembly is such a mess compared to amd64 -- I guess it's a good excuse to work with qemu and arm, if nothing else ;-)

On the topic of ARM, does anybody know of a similar example like this for ARM? One that just shows you how to pass control to C and do some basic I/O?

It would be difficult to write an article similar to this on ARM, because there's no equivalent of what the PC "standard" is to x86 for ARM. Every ARM board and SoC have different boot protocols and peripheral devices.

There are some bootloaders that are commonly used in ARM, such as U-Boot. Perhaps that could be used to get started.

Re: Kernel 101 – Let’s write a Kernel

#102

Post by kjs3 » Thu, Apr 17, 2014, 4:16 AM UTC

dragonwriter wrote: post #45

slashdotaccount wrote: post #11

Earlier quoted context omitted.

If someone here has gone to college, then they'll know what 101 means - course numbering.

> If someone here has gone to college, then they'll know what 101 means - course numbering. At most colleges whose course numbering system I've seen, the kind of introductory course that the idiom "101" refers to would actually be "1"; at many of them, "101" would be an upper division class. Its an idiom that may have connected to some colleges' numbering system at some time, but it mostly exists independently now, a…

I went to 4 colleges, applied to a number of others (not all US based), taught at a few and am giving advice to friends kids now going to college. With minor variations (3-digit v 4-digit course numbers) I've never, ever seen a college course with a single digit course number. Or 2 digit. But then, I've never met an English speaker so culturally tone deaf that they would question the idiom "Foo 101" as being anything other than "intro to Foo".

Re: Kernel 101 – Let’s write a Kernel

#103

Post by kjs3 » Thu, Apr 17, 2014, 4:18 AM UTC

whydo wrote: post #95

The first question is: Why? We already have a whole bunch of operating systems, many of them free. One of the frequent problems with a lot of free/open source software folks is that they lack direction. This type of thing where we do stuff just to do stuff probably won't fly in one of the leading tech companies. Why don't you figure out a real problem people have and look for ways to solve that, instead of just doing…

You must be a real joy at parties.

Re: Kernel 101 – Let’s write a Kernel

#104

Post by TehCorwiz » Fri, Apr 18, 2014, 7:21 AM UTC

Nav_Panel wrote: post #64

TehCorwiz wrote: post #8

Earlier quoted context omitted.

I'm going to give OP the benefit of the doubt on this one. A couple things worth noting, it successfully boots, does not cause a fault of any kind, and is in a position to interact directly with the bare metal. The tools that we use to interact with a *nix system are often just that, bits of code in user-space. This is a kernel-space program. That it does not do any of the memory management or device access yet doesn…

> Maybe implement a game that doesn't have the overhead of an os. I'm in CMU's operating systems class right now and that was one of our projects (our second). The first was writing a stack-tracing debug library, the third was a user-space thread library built on top of a particular kernel spec, and then the fourth was to build a kernel basically from scratch, using our thread library as a test program. Here's a link…

Wow, that's pretty cool. Thanks for the link.