--- wikisrc/ports/evbarm.mdwn 2018/11/07 15:09:41 1.55 +++ wikisrc/ports/evbarm.mdwn 2018/11/11 16:37:42 1.56 @@ -23,20 +23,26 @@ Matt Thomas is the maintainer of NetBSD/ ### CPU types The evbarm port can be built with a variety of CPU options. There are -three main variables: the instruction set, the endianness, and whether -there is hardware floating point. By default the CPU type is "earm", -and this implies little endian (el when explicitly stated), and soft +four main variables: the word size, the instruction set, the +endianness, and whether there is hardware floating point. By default +the CPU type is "earm", and this implies aarch32 (32-bit), \todo cpu +architecture, little endian (el when explicitly stated), and soft (emulated) floating point. Another example, suitable for Raspberry PI -2, is earmv7hf, which is the v7 instruction set, little endian, -and hardware floating point. +2, is earmv7hf, which is aarch32, the v7 instruction set, little +endian, and hardware floating point. Typically, various boards are best compiled with a CPU type that matches the board's CPU and floating point support, but generally a lower CPU instruction set version is workable on a newer board. See build.sh and look for aliases for the evbarm port. -Some processors can operate as arm or the 64-bit ARM variant, aarch64, which is supported by -[[NetBSD/aarch64|aarch64]]. +Through NetBSD 8, the evbarm port has supported exclusively the +aarch32 (32-bit CPU) sub-family of the ARM architecture. Some +processors, such as many supporting the armv8 CPU architecture, also +support a 64-bit instruction set, referred to as aarch64. This is +sometimes referred to as a distinct port, [[NetBSD/aarch64|aarch64]], +with code in src/sys/arch/aarch64, but it is built as the evbarm port +with aarch64 cpu type, and available as the alias evbarm64. ### Kernels and userland