CHOST

The CHOST variable tells the compiler which platform code should be built for. Unlike the CFLAGS variable, which is used for the optimizations, the CHOST variable is fixed and cannot be changed easily.

The profile provides the default CHOST values, but it can be changed in the /etc/portage/make.conf file.

The variable is a dash-separated tuple in the form of ARCH-VENDOR-OS-LIBC:

Values	Descriptions
ARCH	Specifies the CPU architecture.
VENDOR	Specifies the hardware platform or vendor.
OS	Specifies the operating system.
LIBC	Specifies the C library to use.

Only ARCH is strictly required in all cases, but it is good practice to specify all four fields (for Linux machines at least). For operating systems suffixed by a '*', a kernel version should go in its place. Additionally, the LIBC field should usually be ommitted for said operating systems.

The following non-comprehensive table lists some field values known to work:

Architecture	Vendor	Operating System	C Library
required	optional	optional	optional
aarch64 / aarch64_be arm64 (only use this for arm64-apple-{darwin, ios}) alpha arm / armv4 / armv4l / armv4t / armv4tl / armv5te / armv5tel / armv6j / armv7a hppa / hppa1.1 / hppa2.0 / hppa64 i386 / i486 / i586 / i686 ia64 loongarch64 m68k mips / mipsel mips64 / mips64el powerpc / powerpcle powerpc64 / powerpc64le riscv32 / riscv64 s390 / s390x sh / sh4 / sh64 sparc / sparc64 x86_64	apple gentoo ibm (s390{x} only) pc pc_t64 softfloat softfp hardfloat unknown	darwin* elf freebsd* gentoo-freebsd* ios* linux solaris* uclinux	eabi (arm) gnu gnuabi64 (mips) gnuabin32 (mips) gnueabi (arm) gnueabihf (arm) gnux32 (x86_64) musl musleabi (arm) musleabihf (arm) uclibc

Examples

• aarch64-unknown-linux-gnu
• arm64-apple-darwin21
• armv5tel-softfloat-linux-gnueabi
• powerpc-apple-darwin9
• powerpc64le-unknown-linux-musl
• x86_64-pc-linux-gnu
• x86_64-pc-solaris2.11

See also

• Changing the CHOST variable — explains how to change the CHOST variable of an existing system.