Slashdot Mirror
Behind Menuet, an OS Written Entirely In Assembly
angry tapir writes "MenuetOS is an operating system written entirely in assembly language. As a result it's extremely quick and compact (it can even fit on a floppy disk, despite having a GUI). It can run Quake. Two of the developers behind MenuetOS took time out to talk about what inspired them to undertake the daunting task of writing the operating system, the current state of Menuet and future plans for it."
That would be disassembly, which they already mentioned separately as being prohibited. Putting "Point one" and "Point two" in front of clearly incorrect statements doesn't improve anything.
If we can put a man on the moon, why can't we shoot people for Apollo-related non-sequiturs?
for anyone wanting to tinker - it had been forked before they closed it
http://wiki.kolibrios.org/
http://www.kolibrios.org/?p=SVN&kind=dir&loc=/kernel/trunk
Writing in a compiled language is easier, faster, and usually has a better set of pre-written functionality, but never, ever claim that it's going to be more optimized. Even with pipelining updates from the compilers that help the look-ahead caches on the CPU, there's very few times that hand-coded assembler isn't going to be faster.
As CPU's become more complex, this is less and less true. For example, even on the PS2, they created a tool called VCL that preprocessed assembler for you for maximum usage of registers, unrolling, and pipelining. It generated better optimized code than 99% of of coders out there could do on their own and at a fraction of the effort to seriously fully optimize pipelined assembler -- not to mention the asm code was much more maintainable since with handrolled manually pipelined code you may have to re-optimize everything if you change a single register or just a few instructions. Also, things like the auto-unroll and auto-register-assignment a were huge time saver (it could unroll a loop NX and allocate NX registers to interleave SIMD operations to hide latencies).
That's not to say that a really great ASM programmer wouldn't do better than VCL, but he would have to work much much harder. You'd have to track all the registers yourself, remember the pipelining rules and latencies for every single instruction, be willing to experiment with unrolling every loop and counting cycles between unrolled (with prologs/epilogs) and normal versions, know all the possible instruction swaps, synchronize the integer and vector pipelines manually, try nearly all possible instruction orders, etc. Certainly an average assembler programmer wouldn't do as well.