std_detect/detect/os/linux/
arm.rs

1//! Run-time feature detection for ARM on Linux.
2
3use super::auxvec;
4use crate::detect::{Feature, bit, cache};
5
6/// Try to read the features from the auxiliary vector.
7pub(crate) fn detect_features() -> cache::Initializer {
8    let mut value = cache::Initializer::default();
9    let enable_feature = |value: &mut cache::Initializer, f, enable| {
10        if enable {
11            value.set(f as u32);
12        }
13    };
14
15    // The values are part of the platform-specific [asm/hwcap.h][hwcap]
16    //
17    // [hwcap]: https://github.com/torvalds/linux/blob/master/arch/arm/include/uapi/asm/hwcap.h
18    if let Ok(auxv) = auxvec::auxv() {
19        enable_feature(&mut value, Feature::i8mm, bit::test(auxv.hwcap, 27));
20        enable_feature(&mut value, Feature::dotprod, bit::test(auxv.hwcap, 24));
21        enable_feature(&mut value, Feature::neon, bit::test(auxv.hwcap, 12));
22        enable_feature(&mut value, Feature::pmull, bit::test(auxv.hwcap2, 1));
23        enable_feature(&mut value, Feature::crc, bit::test(auxv.hwcap2, 4));
24        enable_feature(&mut value, Feature::aes, bit::test(auxv.hwcap2, 0));
25        // SHA2 requires SHA1 & SHA2 features
26        enable_feature(
27            &mut value,
28            Feature::sha2,
29            bit::test(auxv.hwcap2, 2) && bit::test(auxv.hwcap2, 3),
30        );
31        return value;
32    }
33    value
34}
std_detect/detect/os/linux/arm.rs

std_detect/detect/os/linux/
arm.rs
