uniqlibc

A portable implementation of the POSIX C standard library.

Platform support:

• Linux
  • i386, x86_64, arm, aarch64, riscv64
• FreeBSD
  • i386, x86_64, arm, aarch64, riscv64
• Darwin
  • i386, x86_64, x86_64h, armv4t, armv5, armv6, armv7, armv7s, armv7k, arm64*, arm64e*, arm64_32*
  • arm64 Darwin requires a patched kernel, as XNU doesn't allow static arm64 binaries by default

Building:

To build for x86_64 Linux:

make release

To build for x86_64 Darwin:

make release OS=darwin

To build for arm Linux:

make release ARCH=arm

To build the tests for x86_64 Linux:

make tests

Porting:

To a new architecture:

• Add some headers for your architecture to include/machine
• Add a folder and an arch.mk to platform/<os>/arch/<arch>
• Add your architecture's code to assembly files, currently just crt/start.S and platform/<os>/src/syscall.S
• (Linux only) add your architecture's syscall definitions to include/sys/linux/syscall.h

To a new kernel:

• Add some headers for your kernel to include/sys/<os>
• Program a syscall interface driver in platform/<os>/src/, this should provide functions like read(), write(), open(), etc Try to use as little assembly as possible, the only assembly should be your syscall() function, which all other functions will use
• Add a platform.mk file to platform/<os>/platform.mk (this can add to variables like CFLAGS or be empty)
• Add a folder and an arch.mk to platform/<os>/arch/<arch>

TODO:

• Darwin nanosleep is really bad, I think Apple implements it with signal magic, so figure that out.
• Make arc4random work in chroot, Apple does this, but how?
• Make signal functions work on linux.
• Add support for %a, %g, and %e formats in printf.
• Add support for $N arg number specification in printf.
• Update the whole codebase with comments, especially the stdio parts and crt.
• Fix Linux builds with the stack protector enabled segfaulting