prologic
twtxt.net
 (4h ago)
↳ In-reply-to » very good blog post that reminded me why it's taking so long to ship bbycll — previously i had computed the hashes of every post before storing them in the database, after realizing it's a much better idea to compute the hashes during runtime and only store the post content & timestamp i'm now having to rewrite every function that reads & writes data. i hope the reason as to why i lost motivation is obvious — thankfully i caught it early enough so that once i'm done rewriting just those functions i should™ be able to finalize 1.0-rc with little hassle

@zvava@twtxt.net The problem you now then is you lose integrity of the message content if you compute the hashes at runtime rather than on the way in. So if your message content or database becomes corrupt in any way, so do your hashes.

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movq
www.uninformativ.de
 (1d ago)
↳ In-reply-to » Hmmm I need to figure out a way to reduce the no. of lines of code / complexity of the ARM64 native code emitter for mu (µ). It's insane really, it's a whopping ~6k SLOC, the next biggest source file is the compiler at only ~800 SLOC 🤔

@prologic@twtxt.net This is a really cool project, that’s for sure. 👌

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prologic
twtxt.net
 (1d ago)
↳ In-reply-to » Hmmm I need to figure out a way to reduce the no. of lines of code / complexity of the ARM64 native code emitter for mu (µ). It's insane really, it's a whopping ~6k SLOC, the next biggest source file is the compiler at only ~800 SLOC 🤔

@shinyoukai@neko.laidback.moe Nah it’s more like there’s a lot of repeated code, because when you go from source language to intermediate representation to machine code, well you just end up writing a lot of the same patterns over and over again. I need to dedupe this I think.

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prologic
twtxt.net
 (1d ago)
↳ In-reply-to » Hmmm I need to figure out a way to reduce the no. of lines of code / complexity of the ARM64 native code emitter for mu (µ). It's insane really, it's a whopping ~6k SLOC, the next biggest source file is the compiler at only ~800 SLOC 🤔

The compiler technique I’m using here is to not “emit” most of the runtime if it’s actually never used in your program, and also dropping dead code in the SSA pass.

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prologic
twtxt.net
 (1d ago)
↳ In-reply-to » Hmmm I need to figure out a way to reduce the no. of lines of code / complexity of the ARM64 native code emitter for mu (µ). It's insane really, it's a whopping ~6k SLOC, the next biggest source file is the compiler at only ~800 SLOC 🤔

@movq@www.uninformativ.de I’ve managed to bring a simple “Hello World!” in mu (µ) (at least on macOS / Darwin / ARM64) down to ~86KB (previously ~146KB) 🥳

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prologic
twtxt.net
 (1d ago)

Hmmm I need to figure out a way to reduce the no. of lines of code / complexity of the ARM64 native code emitter for mu (µ). It’s insane really, it’s a whopping ~6k SLOC, the next biggest source file is the compiler at only ~800 SLOC 🤔

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prologic
twtxt.net
 (1d ago)
↳ In-reply-to » My little toy operating system from last year runs in 16-bit Real Mode (like DOS). Since I’ve recently figured out how to switch to 64-bit Long Mode right after BIOS boot, I now have a little program that performs this switch on my toy OS. It will load and run any x86-64 program, assuming it’s freestanding, a flat binary, and small enough (< 128 KiB code, only uses the first 2 MiB of memory).

@movq@www.uninformativ.de I think I can get binaries even smaller with a bit more work and effort 🤔 But yeah still working on the native code generation (at least for macOS targets)

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movq
www.uninformativ.de
 (1d ago)
↳ In-reply-to » My little toy operating system from last year runs in 16-bit Real Mode (like DOS). Since I’ve recently figured out how to switch to 64-bit Long Mode right after BIOS boot, I now have a little program that performs this switch on my toy OS. It will load and run any x86-64 program, assuming it’s freestanding, a flat binary, and small enough (< 128 KiB code, only uses the first 2 MiB of memory).

@prologic@twtxt.net Oh! 🤔

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prologic
twtxt.net
 (2d ago)
↳ In-reply-to » My little toy operating system from last year runs in 16-bit Real Mode (like DOS). Since I’ve recently figured out how to switch to 64-bit Long Mode right after BIOS boot, I now have a little program that performs this switch on my toy OS. It will load and run any x86-64 program, assuming it’s freestanding, a flat binary, and small enough (< 128 KiB code, only uses the first 2 MiB of memory).

@movq@www.uninformativ.de Oh that’s fine, Mu can compile to native code and so far binaries. at least on macOS are in the order of Kb in size 😂

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movq
www.uninformativ.de
 (2d ago)
↳ In-reply-to » My little toy operating system from last year runs in 16-bit Real Mode (like DOS). Since I’ve recently figured out how to switch to 64-bit Long Mode right after BIOS boot, I now have a little program that performs this switch on my toy OS. It will load and run any x86-64 program, assuming it’s freestanding, a flat binary, and small enough (< 128 KiB code, only uses the first 2 MiB of memory).

@prologic@twtxt.net That might be a challenge, at least in 16-bit Real Mode: The OS follows the model of COM files on DOS, i.e. the size of the binary cannot exceed 64 KiB and heap+stack of the running program will have to fit into that same 64 KiB. 😅 (The memory layout is very rigid, each process gets such a 64 KiB slice.)

And in 64-bit Long Mode, there is no “kernel” yet. The thing in the video is literally just a small bare-metal program.

But some day, maybe. 😃

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prologic
twtxt.net
 (2d ago)
↳ In-reply-to » My little toy operating system from last year runs in 16-bit Real Mode (like DOS). Since I’ve recently figured out how to switch to 64-bit Long Mode right after BIOS boot, I now have a little program that performs this switch on my toy OS. It will load and run any x86-64 program, assuming it’s freestanding, a flat binary, and small enough (< 128 KiB code, only uses the first 2 MiB of memory).

@movq@www.uninformativ.de It’d be cool if you could get µ (Mu) running in your little toyOS 🤣 You’d technically only have to swap out the syscall() builtin for whatever your toy OS supports 🤔

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movq
www.uninformativ.de
 (2d ago)
↳ In-reply-to » My little toy operating system from last year runs in 16-bit Real Mode (like DOS). Since I’ve recently figured out how to switch to 64-bit Long Mode right after BIOS boot, I now have a little program that performs this switch on my toy OS. It will load and run any x86-64 program, assuming it’s freestanding, a flat binary, and small enough (< 128 KiB code, only uses the first 2 MiB of memory).

Seeing this run on real hardware is so satisfying, even if it’s just a small example. 😅

https://movq.de/v/ec46b8cf99/netbook.mp4

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movq
www.uninformativ.de
 (2d ago)

My little toy operating system from last year runs in 16-bit Real Mode (like DOS). Since I’ve recently figured out how to switch to 64-bit Long Mode right after BIOS boot, I now have a little program that performs this switch on my toy OS. It will load and run any x86-64 program, assuming it’s freestanding, a flat binary, and small enough (< 128 KiB code, only uses the first 2 MiB of memory).

Here I’m running a little C program (compiled using normal GCC, no Watcom trickery):

https://movq.de/v/b27ced6dcb/los86%2D64.mp4

https://movq.de/v/b27ced6dcb/c.png

Next steps could include:

  • Use Rust instead of C for that 64-bit program?
  • Provide interrupt service routines. (At the moment, it just keeps interrupts disabled.)

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