The target platforms (operating system, compiler toolchain, instruction set) on top of which musl is known to work.

Supported OS

musl is built on the Linux syscall layer. Linux kernel >=2.6.39 is necessary for POSIX conformant behaviour, older kernels will work with varying degrees of non-conformance, 2.4 kernels will only work for simple single-threaded applications.

Supported target architectures (ABIs)

• x86 (SysV ABI)
• x86_64 (SysV ABI)
• arm eabi (armv4t or later, requires gcc >= 4.2.4 for softfp, gcc >= 4.5.4 for hardfloat)
• aarch64
• m68k
• mips/mipsel o32 (MIPS1 with kernel emulation of ll and sc instructions, or MIPS2 or later, softfloat is supported as well)
• mips n32
• mips n64
• microblaze (needs toolchain from xilinx, xilinx gitweb needs gcc >= 4.8 (you can use musl-cross)) and linux 3.13 or this patch.
• powerpc (needs gcc built with –enable-secureplt –with-long-double-64, and -Wl,–secure-plt to link dynamic binaries.)
• powerpc64
• x32 (experimental, due to a number of kernel issues) - requires GCC 4.7 or later (musl-cross is already capable of building a toolchain), you need at least linux 3.4, but note that there were security issues.
• openrisc 1000
• s390x
• sh (experimental) with sh, sheb, sh-nofpu, and sheb-nofpu subarchs (currently this kernel-patch is required for multithread usage)
• riscv64 ( support added since 1.1.23 release ) currently softfp, single-precision, double-precision floating point supported

ABI/ASM manuals

Supported Compilers

Any conformant C and C++ compiler should be able to use musl (to compile and link application code).

As of 2013-09-29, the following compilers are known to be able to compile musl:

• GCC (>=3.4.6)
  • started with gcc 4.8.1, the memset code will be miscompiled. This can be worked around by adding -fno-tree-loop-distribute-patterns to the CFLAGS or passing –enable-optimize=size to configure.
  • musl-cross provides prebuilt cross-compiler toolchains and cross-compiler build instructions.
  • GCC is officially supported using the musl-gcc wrapper or the musl-cross project (for details see Getting started).
• Clang (>=3.2)
  • Instructions for Building LLVM+Clang against musl
  • http://ellcc.org/ ELLCC is a Clang and musl based cross-compiler toolchain for embedded development.
• PCC (>=1.1.0.DEVEL)
• CParser/firm
  • configure musl with –disable-shared, since firm does not yet have position-independent code generation.

Further Information

Bootstrapping a working qemu development environment for microblaze is hard, here are the needed steps to do so.

See Porting for information on how to port musl to a new architecture.