diff options
Diffstat (limited to 'library/stdarch/crates/std_detect/README.md')
| -rw-r--r-- | library/stdarch/crates/std_detect/README.md | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/library/stdarch/crates/std_detect/README.md b/library/stdarch/crates/std_detect/README.md index bea7d941a..71f474d65 100644 --- a/library/stdarch/crates/std_detect/README.md +++ b/library/stdarch/crates/std_detect/README.md @@ -30,6 +30,8 @@ run-time feature detection. When this feature is disabled, `std_detect` assumes that [`getauxval`] is linked to the binary. If that is not the case the behavior is undefined. + Note: This feature is ignored on `*-linux-gnu*` targets, since all `*-linux-gnu*` targets ([since Rust 1.64](https://blog.rust-lang.org/2022/08/01/Increasing-glibc-kernel-requirements.html)) have glibc requirements higher than [glibc 2.16 that added `getauxval`](https://sourceware.org/legacy-ml/libc-announce/2012/msg00000.html), and we can safely assume [`getauxval`] is linked to the binary. + * `std_detect_file_io` (enabled by default, requires `std`): Enable to perform run-time feature detection using file APIs (e.g. `/proc/cpuinfo`, etc.) if other more performant methods fail. This feature requires `libstd` as a dependency, preventing the @@ -44,17 +46,25 @@ crate from working on applications in which `std` is not available. the operating system. `std_detect` assumes that the binary is an user-space application. If you need raw support for querying `cpuid`, consider using the [`cupid`](https://crates.io/crates/cupid) crate. - -* Linux: - * `arm{32, 64}`, `mips{32,64}{,el}`, `powerpc{32,64}{,le}`: `std_detect` + +* Linux/Android: + * `arm{32, 64}`, `mips{32,64}{,el}`, `powerpc{32,64}{,le}`, `riscv{32,64}`: `std_detect` supports these on Linux by querying ELF auxiliary vectors (using `getauxval` - when available), and if that fails, by querying `/proc/cpuinfo`. + when available), and if that fails, by querying `/proc/cpuinfo`. * `arm64`: partial support for doing run-time feature detection by directly querying `mrs` is implemented for Linux >= 4.11, but not enabled by default. * FreeBSD: + * `arm32`, `powerpc64`: `std_detect` supports these on FreeBSD by querying ELF + auxiliary vectors using `sysctl`. * `arm64`: run-time feature detection is implemented by directly querying `mrs`. +* OpenBSD: + * `arm64`: run-time feature detection is implemented by querying `sysctl`. + +* Windows: + * `arm64`: run-time feature detection is implemented by querying `IsProcessorFeaturePresent`. + # License This project is licensed under either of |