Linked by Thom Holwerda on Fri 24th Nov 2006 19:34 UTC, submitted by Lambda
OSNews, Generic OSes House is a demo of software written in Haskell, running in a standalone environment. It is a system than can serve as a platform for exploring various ideas relating to low-level and system-level programming in a high-level functional language.
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RE: would be cool if...
by SomeGuy on Sun 26th Nov 2006 05:29 UTC in reply to "would be cool if..."
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I don't think even hand-optimized assembly is fast enough for full hardware abstraction; Look at all the optimization that goes into writing a graphics driver, and all the extra extensions that go towards bypassing bits of the kernel. Look at the fact that we're still using monolithic kernels mainly because the overhead of system calls on them is lower (and, yes, part of it is code intetia -- "it works, why replace it? -- but part of it is simply that monolithic kernels are faster.)

Also, once you get this "abstraction layer" written, you've got more or less got an entire OS, just with a pluggable scheduler and maybe VFS (memory management would need to be inside the abstraction layer, or you can't really do DMA and memory mapping.). You may not even get a pluggable VFS, because if you've abstracted away the hardware, you probably can't do stuff like wear levelling on flash drives, or optimizing the physical allocation on hard drives.

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RE[2]: would be cool if...
by alphaVirgo on Sun 26th Nov 2006 22:32 in reply to "RE: would be cool if..."
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Assembly code isn't much faster than good C code. The problem is SSE, but a really good compiler (maybe with something slightly less powerful than whole-program analysis) could give you speed comparable to hand-optimized assembly code.

The argument about monolithic kernels is flawed because with a secure language (in particular: no arbitrary pointers like in C) you can pretty much eliminate the overhead of micro-kernels. Even if that is not enough we could have something like a hybrid kernel (drivers as modules loaded into kernel). That would be basically as fast as a "real" monolithic kernel, but without most of the inflexibility and complexity.

Also, you forget that speed is not everything. Drivers and other insecure kernel code are responsible for a lot of system crashes. A more secure language (see Sing# which is used in Singularity) could solve a lot of problems. Maybe you could optinoally enable a garbage collector (good GCs with native code compilers can be pretty fast, don't compare this to Java's performance). If you really need maximum performance you could still combine it with insecure assembly-like code.

I also don't think it's bad that the layer is basically an entire OS. Who cares? That means less code for the actual OS sitting on top of the layer and more drivers for all OSes. There is so much code that every OS reimplements in a very similar way. The only difference is the way plug-n-play works, the VFS, the scheduler, the VM subsystem, processes, threads, single vs multiple address spaces, security, and maybe a few minor things I forgot. The abstraction layer could offer everything that is important. There is absolutely nothing speaking against adding support for what you mentioned at the end (flash drive and physical allocation).

We have so much duplicated code in every OS. The development time could be spent on really important things. Why does nobody sit down and write a cool layer in a secure language (no, please let's do away with stupid C/C++ for system-critical code!).

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