Future plans (or intentions) for Cosmopolitan's bare metal support?

[tkchia]

I am curious to know more about any plans (or intentions) there might be, for Cosmopolitan's support for the bare metal platform.

(E.g. is there any plan to have it support console I/O through a VGA monitor and a PS/2 (or maybe USB?) keyboard, in addition to the serial UART?)

Thank you!

[jart]

We'd love to improve our bare metal support. We already have stdio support through the serial uart port. I also really want ethernet drivers to exist that can be linked-in automatically if you use the berkeley socket system calls. I'd also love to have VGA / PS2 / etc. support if the user explicitly uses libraries we'd provide for that functionality, but it's not something I'd bake into every binary.

[jart]

We already have some code in the repository which renders fonts to the terminal as block characters if you want to use it as a reference:

o//tool/viz/getglyph.com -v NotoSansMono-Regular.ttf | less

[tkchia]

Hello @jart,

Thanks for your suggestions!

I happened to be working on a quick prototype implementation of VGA output (#588, https://github.com/tkchia/cosmopolitan/commit/c42c607c80c2920b585ee1a65a9c66ec68acd609). For now, the code simply assumes that the legacy BIOS has set the screen to a text mode, and has programmed it with an appropriate font.

But I do hope to see how I can properly embed a Unicode font in a program, and use that. I guess I now need to figure out whether it is better to render a TrueType font at runtime, or to precompute a bitmap font from it at build time. 💭

Thank you!

[jart]

Definitely don't hardcode bitmaps. Noto Sans Mono has 2919 glyphs. The file is 290kb. The STB library is tiny.

What you're doing now with the BIOS text mode sounds great too and also the tiniest. We could probably have it replicate serial uart to the BIOS screen display by default for all binaries.

[tkchia]

Hello @jart,

What you're doing now with the BIOS text mode sounds great too and also the tiniest. We could probably have it replicate serial uart to the BIOS screen display by default for all binaries.

OK. In that case, perhaps I will just implement a quick way to map UTF-8 multi-byte characters to CP437 characters where possible.

Thank you!

[jart]

Try the unbing() function which implements a multimapping of UNICODE -> CP437 for this purpose. https://github.com/jart/cosmopolitan/blob/master/libc/fmt/unbing.c For the inverse, see kCp437