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.
@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) 🥳
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 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)
@prologic@twtxt.net Oh! 🤔
@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 😂
@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. 😃
@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 🤔
Seeing this run on real hardware is so satisfying, even if it’s just a small example. 😅
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:
