1 //! Targets the ARMv4T, with code as `t32` code by default.
3 //! Primarily of use for the GBA, but usable with other devices too.
5 //! Please ping @Lokathor if changes are needed.
7 //! This target profile assumes that you have the ARM binutils in your path
8 //! (specifically the linker, `arm-none-eabi-ld`). They can be obtained for free
9 //! for all major OSes from the ARM developer's website, and they may also be
10 //! available in your system's package manager. Unfortunately, the standard
11 //! linker that Rust uses (`lld`) only supports as far back as `ARMv5TE`, so we
12 //! must use the GNU `ld` linker.
14 //! **Important:** This target profile **does not** specify a linker script. You
15 //! just get the default link script when you build a binary for this target.
16 //! The default link script is very likely wrong, so you should use
17 //! `-Clink-arg=-Tmy_script.ld` to override that with a correct linker script.
19 use crate::spec::{cvs, Cc, FramePointer, LinkerFlavor, Lld};
20 use crate::spec::{PanicStrategy, RelocModel, Target, TargetOptions};
22 pub fn target() -> Target {
24 llvm_target: "thumbv4t-none-eabi".into(),
27 /* Data layout args are '-' separated:
29 * stack is 64-bit aligned (EABI)
31 * i64 must be 64-bit aligned (EABI)
32 * mangle names with ELF style
33 * native integers are 32-bit
34 * All other elements are default
36 data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".into(),
37 options: TargetOptions {
39 linker_flavor: LinkerFlavor::Gnu(Cc::No, Lld::No),
40 linker: Some("arm-none-eabi-ld".into()),
42 // extra args passed to the external assembler (assuming `arm-none-eabi-as`):
43 // * activate t32/a32 interworking
45 // * use little-endian
46 asm_args: cvs!["-mthumb-interwork", "-march=armv4t", "-mlittle-endian",],
48 // minimum extra features, these cannot be disabled via -C
49 // Also force-enable 32-bit atomics, which allows the use of atomic load/store only.
50 // The resulting atomics are ABI incompatible with atomics backed by libatomic.
51 features: "+soft-float,+strict-align,+atomics-32".into(),
53 panic_strategy: PanicStrategy::Abort,
54 relocation_model: RelocModel::Static,
55 // suggested from thumb_base, rust-lang/rust#44993.
56 emit_debug_gdb_scripts: false,
57 // suggested from thumb_base, with no-os gcc/clang use 8-bit enums
59 frame_pointer: FramePointer::MayOmit,
61 main_needs_argc_argv: false,
63 // don't have atomic compare-and-swap
65 has_thumb_interworking: true,
67 ..super::thumb_base::opts()