diff options
Diffstat (limited to 'cortex-m-rt/src')
| -rw-r--r-- | cortex-m-rt/src/lib.rs | 36 |
1 files changed, 10 insertions, 26 deletions
diff --git a/cortex-m-rt/src/lib.rs b/cortex-m-rt/src/lib.rs index 524b161..e2dd667 100644 --- a/cortex-m-rt/src/lib.rs +++ b/cortex-m-rt/src/lib.rs @@ -937,9 +937,6 @@ pub unsafe extern "C" fn Reset() -> ! { static mut __sdata: u32; static mut __edata: u32; static __sidata: u32; - - // This symbol will be provided by the user via `#[entry]` - fn main() -> !; } extern "Rust" { @@ -956,33 +953,20 @@ pub unsafe extern "C" fn Reset() -> ! { #[allow(clippy::match_single_binding)] match () { #[cfg(not(has_fpu))] - () => main(), + () => { + extern "C" { + // This symbol will be provided by the user via `#[entry]` + fn main() -> !; + } + main() + } #[cfg(has_fpu)] () => { - const SCB_CPACR: *mut u32 = 0xE000_ED88 as *mut u32; - const SCB_CPACR_FPU_ENABLE: u32 = 0b01_01 << 20; - const SCB_CPACR_FPU_USER: u32 = 0b10_10 << 20; - - // enable the FPU - core::ptr::write_volatile( - SCB_CPACR, - *SCB_CPACR | SCB_CPACR_FPU_ENABLE | SCB_CPACR_FPU_USER, - ); - - cortex_m::asm::dsb(); - cortex_m::asm::isb(); - - // this is used to prevent the compiler from inlining the user `main` into the reset - // handler. Inlining can cause the FPU instructions in the user `main` to be executed - // before enabling the FPU, and that would produce a hard to diagnose hard fault at - // runtime. - #[inline(never)] - #[export_name = "ResetTrampoline"] - fn trampoline() -> ! { - unsafe { main() } + extern "C" { + fn FpuTrampoline() -> !; } - trampoline() + FpuTrampoline() } } } |