Commit Graph

23 Commits (1f1f3cd4775479f79b952c31fe6efd52ef2e2271)

Author SHA1 Message Date
Justine Tunney 1f1f3cd477 Fix bug in code written a priori 2020-08-31 21:02:14 -07:00
Justine Tunney f213556366 Add binfmt_misc workaround detector to builds
This is a recently introduced Linux Kernel feature that gives people
like Debian package mantainers the power to arbitrarily redefine how
executables are interpreted by the kernel. If your system gets tuned
this way and you're not able to disable it, then you need to restore
default behavior for the APE MZqFpD prefix as follows:

    sudo sh -c "echo ':APE:M::MZqFpD::/bin/sh:' >/proc/sys/fs/binfmt_misc/register"

This prefix will cover all .com executables built with this tooling.
Please don't run the above command unless you're certain you need it.
See #2 for additional context.
2020-08-31 20:09:23 -07:00
Justine Tunney bd29223891 Fix bugs and have emulator emulate itself 2020-08-31 05:17:31 -07:00
Justine Tunney 5aabacb361 Add pseudoteletypewriter to emulator
https://justine.storage.googleapis.com/emulator628.mp4
2020-08-29 23:51:09 -07:00
Justine Tunney e86cff8ba0 Fix printvideo regression and minor improvements 2020-08-26 09:41:07 -07:00
Justine Tunney eb4bb43275 Fix close() return code for Winsock
Thus fixing tool/net/dig.com on NT.
2020-08-25 09:33:11 -07:00
Justine Tunney f4f4caab0e Add x86_64-linux-gnu emulator
I wanted a tiny scriptable meltdown proof way to run userspace programs
and visualize how program execution impacts memory. It helps to explain
how things like Actually Portable Executable works. It can show you how
the GCC generated code is going about manipulating matrices and more. I
didn't feel fully comfortable with Qemu and Bochs because I'm not smart
enough to understand them. I wanted something like gVisor but with much
stronger levels of assurances. I wanted a single binary that'll run, on
all major operating systems with an embedded GPL barrier ZIP filesystem
that is tiny enough to transpile to JavaScript and run in browsers too.

https://justine.storage.googleapis.com/emulator625.mp4
2020-08-25 04:43:42 -07:00
Justine Tunney 467504308a Improve emulator color math
Video game emulators seem to convert colors for modern displays poorly.
Check out https://youtu.be/Eds63YbGhDQ?t=481 where we notice in the CRT
displays Super Mario Bros with a blue sky, whereas the PC shows purple.

It's likely b/c NTSC used Illuminant C whereas sRGB uses Illuminant D65.
See the improvement: https://justine.storage.googleapis.com/nesemu3.png
Now you can play video games in the terminal as they looked in the 80's.

This change also reduces CPU usage to a third.
2020-07-02 20:48:57 -07:00
Justine Tunney 72b654cb6c Add NES emulator
It's now possible to play classic video game roms with teletypewriters.
https://justine.storage.googleapis.com/nesemu.png
2020-07-02 13:46:08 -07:00
Justine Tunney 4918121810 Add new calculator app
Cosmopolitan makes it easy to build and maintain programming languages,
since it abstracts system call #ifdef toil, so you can focus on vision.
Here's an example of a language that isn't turing complete, weighing in
at <1,000 lines of modern C, intended to help with testing libc / libm:

    .1 .2 + .3 - abs epsilon < assert
    pi sqrt pi sqrt * pi - abs epsilon < assert
    -.5 rint dup 0 = assert signbit assert
    -.5 nearbyint dup 0 = assert signbit assert
    -.5 ceil dup 0 = assert signbit assert
    -.5 trunc dup 0 = assert signbit assert
    -.5 round -1 = assert
    -.5 floor -1 = assert
    0 signbit ! assert

CALCULATOR.COM pays homage to CALC.EXE recently removed from Windows 10.
Microsoft should bundle this app instead. It too is roughly 100kb, works
just fine w/ command prompt, and portable since it runs on Mac/Linux/BSD
too while bundling even more features than the calculator on Google.com.

It should be possible to run CALCULATOR.COM on Android and iOS too, just
in case anyone needs a backend pipe driven framework, for graphical user
interfaces of calculators. Sadly we haven't tried it since we don't know
how to run software on telephones so the system call support is a priori
2020-06-30 19:58:08 -07:00
Justine Tunney ac00be1a4e Make small fixes and oops ran clang-format on dtoa 2020-06-30 19:55:47 -07:00
Justine Tunney b5b60015f5 Add spellcheck example
One of the benefits of implementing system call support from scratch is
that we're able to have embedded zip filesystem support which trickles
into libraries such as stdio, without unportable symbolic interposition.
It's also be great if we could say open("gs://bucket/object", O_RDONLY)
for seamless GCS, similar to Java NIO, but abstracted by the C library.
2020-06-27 12:25:40 -07:00
Justine Tunney 0ad0408ac6 Fix stdio bug w/ embedded zip filesystem 2020-06-27 11:48:29 -07:00
Justine Tunney d5c3a6f039 Add example for auto debugging and asm() usage 2020-06-26 16:09:04 -07:00
Justine Tunney d51409ccd9 Add glob and some finer tuning of documentation 2020-06-21 15:23:35 -07:00
Justine Tunney 799e24a87b Reduce build log verbosity with preprocessor trick 2020-06-18 23:07:58 -07:00
Justine Tunney a2c2d14100 Add further clarity to example package 2020-06-18 16:23:41 -07:00
Justine Tunney d2b20422c8 Add about section to readme 2020-06-16 16:58:35 -07:00
Justine Tunney b1755cea5d Darth Raadt is holding the Bell Labs ABI hostage
The binary system interfaces designed at Bell Labs were what helped our
friends like Linus Torvalds become successful. It's why Torvalds always
respected syscall abi and made every effort to not break the userspace.

Sadly OpenBSD developer Theo de Raadt thinks respecting Bell interfaces
is a risk for security and conjured up the Return Oriented Programming
bogeyman to justify his policies, per https://lwn.net/Articles/806776/

See libc/nexgen32e/gc.S where we use ROP concepts for garbage collection
in C due to our belief that powerful programming techniques can be good.
See https://opensource.googleblog.com/2017/03/operation-rosehub.html for
an example of something similar to rop but potentially more of a concern
2020-06-16 06:41:10 -07:00
Justine Tunney 2e979c00c3 Polish up repository and other revisions 2020-06-16 06:38:43 -07:00
Justine Tunney d23bb6612e Make it easy to create new packages 2020-06-15 22:09:03 -07:00
Justine Tunney b4269930f7 Add scouts honor escape hatch for source embedding 2020-06-15 19:01:28 -07:00
Justine Tunney c91b3c5006 Initial import 2020-06-15 07:18:57 -07:00