diff options
Diffstat (limited to 'compiler/rustc_target/src/spec/x86_64_unknown_uefi.rs')
-rw-r--r-- | compiler/rustc_target/src/spec/x86_64_unknown_uefi.rs | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/compiler/rustc_target/src/spec/x86_64_unknown_uefi.rs b/compiler/rustc_target/src/spec/x86_64_unknown_uefi.rs new file mode 100644 index 000000000..a7ae17839 --- /dev/null +++ b/compiler/rustc_target/src/spec/x86_64_unknown_uefi.rs @@ -0,0 +1,36 @@ +// This defines the amd64 target for UEFI systems as described in the UEFI specification. See the +// uefi-base module for generic UEFI options. On x86_64 systems (mostly called "x64" in the spec) +// UEFI systems always run in long-mode, have the interrupt-controller pre-configured and force a +// single-CPU execution. +// The win64 ABI is used. It differs from the sysv64 ABI, so we must use a windows target with +// LLVM. "x86_64-unknown-windows" is used to get the minimal subset of windows-specific features. + +use crate::spec::Target; + +pub fn target() -> Target { + let mut base = super::uefi_msvc_base::opts(); + base.cpu = "x86-64".into(); + base.max_atomic_width = Some(64); + + // We disable MMX and SSE for now, even though UEFI allows using them. Problem is, you have to + // enable these CPU features explicitly before their first use, otherwise their instructions + // will trigger an exception. Rust does not inject any code that enables AVX/MMX/SSE + // instruction sets, so this must be done by the firmware. However, existing firmware is known + // to leave these uninitialized, thus triggering exceptions if we make use of them. Which is + // why we avoid them and instead use soft-floats. This is also what GRUB and friends did so + // far. + // + // If you initialize FP units yourself, you can override these flags with custom linker + // arguments, thus giving you access to full MMX/SSE acceleration. + base.features = "-mmx,-sse,+soft-float".into(); + + Target { + llvm_target: "x86_64-unknown-windows".into(), + pointer_width: 64, + data_layout: "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128" + .into(), + arch: "x86_64".into(), + + options: base, + } +} |