diff --git a/crates/std_detect/src/detect/os/freebsd/arm.rs b/crates/std_detect/src/detect/os/freebsd/arm.rs new file mode 100644 index 0000000000..e13847dcbd --- /dev/null +++ b/crates/std_detect/src/detect/os/freebsd/arm.rs @@ -0,0 +1,27 @@ +//! Run-time feature detection for ARM on FreeBSD + +use crate::detect::{Feature, cache}; +use super::{auxvec}; + +/// Performs run-time feature detection. +#[inline] +pub fn check_for(x: Feature) -> bool { + cache::test(x as u32, detect_features) +} + +/// Try to read the features from the auxiliary vector +fn detect_features() -> cache::Initializer { + let mut value = cache::Initializer::default(); + let enable_feature = |value: &mut cache::Initializer, f, enable| { + if enable { + value.set(f as u32); + } + }; + + if let Ok(auxv) = auxvec::auxv() { + enable_feature(&mut value, Feature::neon, auxv.hwcap & 0x00001000 != 0); + enable_feature(&mut value, Feature::pmull, auxv.hwcap2 & 0x00000002 != 0); + return value; + } + value +} diff --git a/crates/std_detect/src/detect/os/freebsd/auxvec.rs b/crates/std_detect/src/detect/os/freebsd/auxvec.rs new file mode 100644 index 0000000000..fd2bd500bf --- /dev/null +++ b/crates/std_detect/src/detect/os/freebsd/auxvec.rs @@ -0,0 +1,86 @@ +//! Parses ELF auxiliary vectors. +#![cfg_attr(any(target_arch = "arm", target_arch = "powerpc64"), allow(dead_code))] + +/// Key to access the CPU Hardware capabilities bitfield. +pub(crate) const AT_HWCAP: usize = 25; +/// Key to access the CPU Hardware capabilities 2 bitfield. +pub(crate) const AT_HWCAP2: usize = 26; + +/// Cache HWCAP bitfields of the ELF Auxiliary Vector. +/// +/// If an entry cannot be read all the bits in the bitfield are set to zero. +/// This should be interpreted as all the features being disabled. +#[derive(Debug, Copy, Clone)] +pub(crate) struct AuxVec { + pub hwcap: usize, + pub hwcap2: usize, +} + +/// ELF Auxiliary Vector +/// +/// The auxiliary vector is a memory region in a running ELF program's stack +/// composed of (key: usize, value: usize) pairs. +/// +/// The keys used in the aux vector are platform dependent. For FreeBSD, they are +/// defined in [sys/elf_common.h][elf_common_h]. The hardware capabilities of a given +/// CPU can be queried with the `AT_HWCAP` and `AT_HWCAP2` keys. +/// +/// Note that run-time feature detection is not invoked for features that can +/// be detected at compile-time. +/// +/// [elf_common.h]: https://svnweb.freebsd.org/base/release/12.0.0/sys/sys/elf_common.h?revision=341707 +pub(crate) fn auxv() -> Result { + if let Ok(hwcap) = archauxv(AT_HWCAP) { + if let Ok(hwcap2) = archauxv(AT_HWCAP2) { + if hwcap != 0 && hwcap2 != 0 { + return Ok(AuxVec { hwcap, hwcap2 }); + } + } + } + Err(()) +} + +/// Tries to read the `key` from the auxiliary vector. +fn archauxv(key: usize) -> Result { + use mem; + + #[derive (Copy, Clone)] + #[repr(C)] + pub struct Elf_Auxinfo { + pub a_type: usize, + pub a_un: unnamed, + } + #[derive (Copy, Clone)] + #[repr(C)] + pub union unnamed { + pub a_val: libc::c_long, + pub a_ptr: *mut libc::c_void, + pub a_fcn: Option ()>, + } + + let mut auxv: [Elf_Auxinfo; 27] = + [Elf_Auxinfo{a_type: 0, a_un: unnamed{a_val: 0,},}; 27]; + + let mut len: libc::c_uint = mem::size_of_val(&auxv) as libc::c_uint; + + unsafe { + let mut mib = [libc::CTL_KERN, libc::KERN_PROC, libc::KERN_PROC_AUXV, libc::getpid()]; + + let ret = libc::sysctl(mib.as_mut_ptr(), + mib.len() as u32, + &mut auxv as *mut _ as *mut _, + &mut len as *mut _ as *mut _, + 0 as *mut libc::c_void, + 0, + ); + + if ret != -1 { + for i in 0..auxv.len() { + if auxv[i].a_type == key { + return Ok(auxv[i].a_un.a_val as usize); + } + } + } + } + return Ok(0); +} diff --git a/crates/std_detect/src/detect/os/freebsd/mod.rs b/crates/std_detect/src/detect/os/freebsd/mod.rs index 952b4baf0f..1a5338a355 100644 --- a/crates/std_detect/src/detect/os/freebsd/mod.rs +++ b/crates/std_detect/src/detect/os/freebsd/mod.rs @@ -1,9 +1,17 @@ //! Run-time feature detection on FreeBSD +mod auxvec; + cfg_if! { if #[cfg(target_arch = "aarch64")] { mod aarch64; pub use self::aarch64::check_for; + } else if #[cfg(target_arch = "arm")] { + mod arm; + pub use self::arm::check_for; + } else if #[cfg(target_arch = "powerpc64")] { + mod powerpc; + pub use self::powerpc::check_for; } else { use crate::arch::detect::Feature; /// Performs run-time feature detection. diff --git a/crates/std_detect/src/detect/os/freebsd/powerpc.rs b/crates/std_detect/src/detect/os/freebsd/powerpc.rs new file mode 100644 index 0000000000..c7f761d4d6 --- /dev/null +++ b/crates/std_detect/src/detect/os/freebsd/powerpc.rs @@ -0,0 +1,27 @@ +//! Run-time feature detection for PowerPC on FreeBSD. + +use crate::detect::{Feature, cache}; +use super::{auxvec}; + +/// Performs run-time feature detection. +#[inline] +pub fn check_for(x: Feature) -> bool { + cache::test(x as u32, detect_features) +} + +fn detect_features() -> cache::Initializer { + let mut value = cache::Initializer::default(); + let enable_feature = |value: &mut cache::Initializer, f, enable| { + if enable { + value.set(f as u32); + } + }; + + if let Ok(auxv) = auxvec::auxv() { + enable_feature(&mut value, Feature::altivec, auxv.hwcap & 0x10000000 != 0); + enable_feature(&mut value, Feature::vsx, auxv.hwcap & 0x00000080 != 0); + enable_feature(&mut value, Feature::power8, auxv.hwcap2 & 0x80000000 != 0); + return value; + } + value +}