face6b61d5
This is an experimental proof of concept demo:
make -j8 o//examples/i386.i386.com
o//examples/i386.i386.com --32
echo $? # <-- prints main32's argc parameter
Please note there's no libc support at the moment. This change is just
for fun and shouldn't be interpreted as intent to support. Having this
project on the whole support i386 would be tough because the calling
conventions are so different. There really isn't much in the way of low
hanging fruit opportunities to do something like NOP out REX prefixes
and call it a day. It'd likely need disjoint builds or possibly better
yet really cleverly crafted code generation in //third_party/chibicc!
Another challenge is is that Linux changed its SYSCALL ordinals when it
migrated from i386 to x86_64. Linux used to use the same magic numbers
as everyone else for functions like exit/write/read/etc. BSDs on the
other hand didn't pointlessly renumber things. So we'd need to find a
way to define the ordinals in libc/sysv/syscalls.sh twice for Linux. The
same goes for other ISAs too. Especially MIPS. For the Linux Kernel
alone, syscall magic numbers and data structure layouts are totally
different, and that's likely the case for other ISAs on other operating
systems too. Probably because ISA code historically got contributed to
open source by the companies that made the chips. Ulrich Drepper wrote
an amusing essay on the subject some years back.
|
||
|---|---|---|
| .github | ||
| .vscode | ||
| ape | ||
| build | ||
| dsp | ||
| examples | ||
| libc | ||
| net | ||
| test | ||
| third_party | ||
| tool | ||
| usr/share | ||
| .clang-format | ||
| .gitignore | ||
| hello.com | ||
| Makefile | ||
| NOTICE | ||
| README.md | ||
Cosmopolitan
Cosmopolitan Libc makes C a build-once run-anywhere language, like Java, except it doesn't need an interpreter or virtual machine. Instead, it reconfigures stock GCC and Clang to output a POSIX-approved polyglot format that runs natively on Linux + Mac + Windows + FreeBSD + OpenBSD + NetBSD + BIOS with the best possible performance and the tiniest footprint imaginable.
Background
For an introduction to this project, please read the αcτµαlly pδrταblε εxεcµταblε blog post and cosmopolitan libc website. We also have API documentation.
Getting Started
If you're doing your development work on Linux or BSD then you need just five files to get started:
wget https://justine.lol/cosmopolitan/cosmopolitan-amalgamation-0.2.zip
unzip cosmopolitan-amalgamation-0.2.zip
printf 'main() { printf("hello world\\n"); }\n' >hello.c
gcc -g -O -static -nostdlib -nostdinc -fno-pie -no-pie -mno-red-zone \
-o hello.com.dbg hello.c -fuse-ld=bfd -Wl,-T,ape.lds \
-include cosmopolitan.h crt.o ape.o cosmopolitan.a
objcopy -S -O binary hello.com.dbg hello.com
./hello.com
If you're developing on Windows or MacOS then you need to download an x86_64-pc-linux-gnu toolchain beforehand. See the Compiling on Windows tutorial. It's needed because the ELF object format is what makes universal binaries possible.
Cosmopolitan can also be compiled from source on any Linux distro.
wget https://justine.lol/cosmopolitan/cosmopolitan-0.2.tar.gz
tar xf cosmopolitan-0.2.tar.gz # see releases page
cd cosmopolitan-0.2
make -j16
o//examples/hello.com
find o -name \*.com | xargs ls -rShal | less