The new blacklistd sounds interesting, are the plans to make it available on other operating system as well?
Is anyone using NetBSD on a "Orange Pi" board (AllWinner A20, it's mentioned in the release notes so I guess it will work)?
What about the "Orange Pi Plus" (AllWinner H3)?
These boards offer a lot of performance for the buck.
I'm not sure if I understand well the "rump kernel"/"anykernel" idea as implemented in NetBSD. Could anybody please help me with that - specifically, how this differs from a microkernel?
My current idea is that I can take the current NetBSD kernel and:
a) for some (any? or only some?) hardware subsystems, ask the kernel (by some switch/config? where?) to run drivers in userspace, in "microkernel-like" way (and thus they reboot transparently in case of failure/bug/crash?), at some performance cost;
b) compile out/disable (? by some preprocessor directive?) some subsystems of the kernel, so that I get a "smaller" kernel e.g. for embedded machines which don't have video-card/GPU hardware;
and probably also combine the both above approaches together - i.e. build a reduced kernel like in (b), and then optionally run any missing subsystems/drivers like in (a).
There is a difference between what is possible to do with rump kernels and what NetBSD is currently doing with them. The basic point is to be able to use the same code in different contexts, so in theory you could use rump kernels in implementing a microkernel. However, AFAIK NetBSD currently uses it for (optionally) running filesystems in userland (so you can mount potentially corrupted file systems without crashing the kernel) and for testing. Your (b) is a separate thing that has always been possible in NetBSD (there is also loadable kernel module support). More things could be made to work as userland drivers easily but could still require glue to make it actually work. I don't understand the details but there are multiple ways to make the glue and it can be easier if you are trying to get NetBSD drivers to run in NetBSD userland.
You can also use rump kernels to make an application that runs directly on Xen, KVM, or hardware or that e.g. uses NetBSD file system code on Linux (or Cygwin) userland. Much of this still need some work to do what you want, but less than writing the drivers from scratch, much less maintining them. rumpkernel.org is starting to have packages for some applications. This doesn't require otherwise using NetBSD.
Uh, so only FS for now? That's sure nice, and a nice start, but I really thought there's more to it. Thanks for the clarification & and details.
(I remembered that Haiku got network drivers from some WhatsitBSD, so I thought those are maybe there too, but it seems it was FreeBSD actually, so just some confusion of mine. So no microkernel there, it seems. Bummer.)
As to running on Xen etc, that was what I seemed to vaguely remeber as what rump kernels mean, so I was really confused and surprised to slowly find out that the NetBSD usage of the term seems to diverge quite substantially, as far as I can (or can't?) understand. Hmph.
I just saw this so not sure if you'll actually see this response, but rump kernel doesn't imply Xen or such, that is just a common thing people want to do with them. It just means kernel drivers that can be used outside the kernel. Anykernel refers to a kernel that can be used that way with minimal differences and without modifying individual drivers. So rump kernel is "libkernel" and an anykernel is one way to get a rump kernel.
Thanks. The problem is, I actually have already read the appropriate sections of the FAQ & some rumpkernel.org pages, but I'm still confused. (I've written my original question out of frustration that things didn't become clear after all the reading.) I'm starting to think it may be best to dive in and try reading the "book" referenced in the FAQ (i.e. the Antti's PhD paper). Seems actually very approachable for a regular non-sciency engineer, from first looks. And/or maybe the "tutorial" I've found at https://github.com/rumpkernel/wiki/wiki/Tutorial:-Getting-st...
"a" is sort of orthogonal to rump kernels, but yes, you can run at least file system drivers transparently as userspace servers (just give -o rump to mount(8)). I've also run a USB modem driver as a userspace server, in the "the kernel I'm running doesn't contain support, but a future kernel revision has" fashion.
For "b", rump kernels don't support "compiling out". Rather, the idea is to "link in" only what you need, as in "don't need file systems in that particular application? well don't link in VFS then".
I'm not sure if you're right or wrong, but maybe the rump kernel FAQ at http://wiki.rumpkernel.org/Info:-FAQ will straighten your thoughts. In the regrettable case that it doesn't, you can always suggestion additional questions.
Actually, I've asked my question after trying to do some basic reading on my own, but it only deepened my confusion, unfortunately. I vaguely remembered that "rump kernels" seemed to mean "assume we're on Xen/KVM/... and make use of that", or a notion of "library kernels" -- one of those two, though not 100% sure which one (or both?). But then from some NetBSD docs/wikis/... it started to look to me like they're adding another term "anykernel" here and there, and then naming with that some microkernel-like stuff, like mounting stuff in userspace, but then not sure why naming the option as "rump", etc -- and all of that made me more and more confused, instead of less. And that's what made me ask here.
It's not without flaws, but it's compelling enough that I live with its shortcomings.
What do I like ?
1) One codebase that supports 57 targets. This code is well exercised.
2) Nice balance of conservatism and progressiveness. Seems well-rooted in tradition, but still progressive/interesting with things like the RUMP kernels[0], Lua kernel interface[1], etc.
3) Plays well with others. It's probably out-and-about more than people realize. I once had a printer that had NetBSD as its OS. Original Apple airport units[2] were NetBSD (as is a good amount of MacOS X userland[3], apparently) -- but as an explicit product (i.e.: using it directly by choice), it's nice, and it interacts well enough with other systems as well. It's got a simple httpd in the base, and ftpd, ssh, etc for swapping files in/out in an emergency. It will read FAT filesystems, or ext2,3(,4?), it runs firefox, etc. (admittedly, I don't care too much about high-level end-user software, and depending on what you think you need, you might be better served elsewhere -- including moving to Windows or MacOS X).
4) I've used NetBSD as my principle OS since 1.6 (2002). It has supported my work, taught me things, and kept my interest. If you're interested in seeing what it's about, you should install it and give it a good try.
Thanks for the informative reply. One thing I don't quite know: what is the package ecosystem like? Are packages generally up to date? Do people usually install from source, or use binaries?
I've had accelerated Intel integrated gfx, working wireless (Intel Centrino 4965/5000/1000, 1000/2000/6000, 7260/7265/3160), tuneable CPU frequency...
If you've got the luxury of some medium that you can do a test install on, just do it. The install is text-based and really simple, so you shouldn't get hung up there. I assume you'll want X11, so you'll run "X -configure" to generate an xorg.conf. Grab the pkgsrc[0] framework to build 3rd party apps from source, or, use pkg_add(1)[1] (I don't know what's currently available for NetBSD7 in terms of pre-built packages; quick check shows at least some packages are, and they're _probably_ the most popular ones)
Ya, OpenBSD has done some pretty remarkable work on the laptop front, and I find it interesting, because it's not where I would have guessed they'd be interested. They're leaders in the accelerated gfx and wireless. I'm used to thinking of the project being more focused on hardening applications. Certainly NetBSD has benefited from the work done in Open, by way of the famous *BSD cross-pollination.
I hope you enjoy Net even a fraction as much as I do.
I am so excited! I have been waiting to have an excuse to spend some time with BSD, Lua kernel scripting is definitely going to be something I mess with this weekend.
The manpages for lua(4) and luactl(8) may be of help.
lua(4) is the device driver which allows you manage Lua states in the kernel through an ioctl interface. With luactl(8) you can create and destroy states, load and execute scripts, and require modules.
Example:
1. Load lua(4) driver
modload lua
2. Create a Lua state in the kernel
luactl create s0
3. Load and execute a script named hello.lua
luactl load s0 ./hello.lua
4. dmesg
A Lua state is created empty. In order to load the standard libs (base, string, table, ...) into that state you'd need to do a luaL_openlibs(). Even though the libs are compiled into lua(4), you can't easily load them with luactl. [1] is a patch that adds a 'openlibs' command to luactl. After you apply it and recompile luactl, you can do that:
luactl openlibs s0
Btw, we've ported Lua test suite to the NetBSD kernel in this year's GSoC. Part of the work was on porting parts of the standard libraries which were not available in kernel Lua (e.g., os, io, math). Take a look at [2].
Let me know if you need any help. My email address is my HN username at gmail.com
The new blacklistd sounds interesting, are the plans to make it available on other operating system as well?
Is anyone using NetBSD on a "Orange Pi" board (AllWinner A20, it's mentioned in the release notes so I guess it will work)? What about the "Orange Pi Plus" (AllWinner H3)? These boards offer a lot of performance for the buck.