//! examples/lock_cost.rs #![deny(unsafe_code)] #![deny(warnings)] #![no_main] #![no_std] use panic_semihosting as _; #[rtic::app(device = lm3s6965)] mod app { #[shared] struct Shared { shared: u32, } #[local] struct Local {} #[init] fn init(_: init::Context) -> (Shared, Local, init::Monotonics) { (Shared { shared: 0 }, Local {}, init::Monotonics()) } #[idle(shared = [shared])] #[inline(never)] fn idle(mut cx: idle::Context) -> ! { cx.shared.shared.lock(|shared| *shared += 1); loop { cortex_m::asm::nop(); } } #[task(binds = UART0, shared = [shared])] fn uart0(mut cx: uart0::Context) { cx.shared.shared.lock(|shared| *shared += 1); } } // cargo objdump --example lock_cost --target thumbv7m-none-eabi --release --features inline-asm -- --disassemble > lock_cost.objdump // 0000016c : // 16c: 80 b5 push {r7, lr} // 16e: 6f 46 mov r7, sp // 170: 01 78 ldrb r1, [r0] // 172: 39 b1 cbz r1, 0x184 @ imm = #14 // 174: 40 f2 00 00 movw r0, #0 // 178: c2 f2 00 00 movt r0, #8192 // 17c: 01 68 ldr r1, [r0] // 17e: 01 31 adds r1, #1 // 180: 01 60 str r1, [r0] // 182: 0f e0 b 0x1a4 @ imm = #30 // 184: 01 21 movs r1, #1 // 186: 01 70 strb r1, [r0] // 188: e0 21 movs r1, #224 // 18a: 81 f3 11 88 msr basepri, r1 // 18e: 40 f2 00 01 movw r1, #0 // 192: c2 f2 00 01 movt r1, #8192 // 196: 0a 68 ldr r2, [r1] // 198: 01 32 adds r2, #1 // 19a: 0a 60 str r2, [r1] // 19c: 00 21 movs r1, #0 // 19e: 81 f3 11 88 msr basepri, r1 // 1a2: 01 70 strb r1, [r0] // 1a4: 00 bf nop // 1a6: fd e7 b 0x1a4 @ imm = #-6 // 000001a8 : // 1a8: 80 b5 push {r7, lr} // 1aa: 6f 46 mov r7, sp // 1ac: 40 f2 00 00 movw r0, #0 // 1b0: c2 f2 00 00 movt r0, #8192 // 1b4: 01 68 ldr r1, [r0] // 1b6: 01 31 adds r1, #1 // 1b8: 01 60 str r1, [r0] // 1ba: 00 20 movs r0, #0 // 1bc: 80 f3 11 88 msr basepri, r0 // 1c0: 80 bd pop {r7, pc}