Merge pull request #41 from HarkonenBade/down-with-ub

Apply critical sections to uses of registers where exclusivity is not guaranteed

Author: therealprof

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 ### Changed
 
 - Optimize delay implemenation (#42) - @david-sawatzke
+- Enforced more rigorous safety guarentees (#41 - Very breaking change) - @HarkonenBade
 
 ### Fixed
 

examples/adc_values.rs

@@ -29,40 +29,41 @@ fn main() -> ! {
         hal::stm32::Peripherals::take(),
         cortex_m::peripheral::Peripherals::take(),
     ) {
-        let gpioa = p.GPIOA.split();
-        let rcc = p.RCC.constrain();
-        let clocks = rcc.cfgr.sysclk(8.mhz()).freeze();
+        cortex_m::interrupt::free(move |cs| {
+            let mut flash = p.FLASH;
+            let mut rcc = p.RCC.configure().sysclk(8.mhz()).freeze(&mut flash);
 
-        let mut syst = cp.SYST;
+            let gpioa = p.GPIOA.split(&mut rcc);
 
-        // Set source for SysTick counter, here full operating frequency (== 8MHz)
-        syst.set_clock_source(Core);
+            let mut syst = cp.SYST;
 
-        // Set reload value, i.e. timer delay 8 MHz/counts
-        syst.set_reload(8_000_000 - 1);
+            // Set source for SysTick counter, here full operating frequency (== 8MHz)
+            syst.set_clock_source(Core);
 
-        // Start SysTick counter
-        syst.enable_counter();
+            // Set reload value, i.e. timer delay 8 MHz/counts
+            syst.set_reload(8_000_000 - 1);
 
-        // Start SysTick interrupt generation
-        syst.enable_interrupt();
+            // Start SysTick counter
+            syst.enable_counter();
 
-        // USART1 at PA9 (TX) and PA10(RX)
-        let tx = gpioa.pa9.into_alternate_af1();
-        let rx = gpioa.pa10.into_alternate_af1();
+            // Start SysTick interrupt generation
+            syst.enable_interrupt();
 
-        // Initialiase UART
-        let (mut tx, _) =
-            hal::serial::Serial::usart1(p.USART1, (tx, rx), 115_200.bps(), clocks).split();
+            // USART1 at PA9 (TX) and PA10(RX)
+            let tx = gpioa.pa9.into_alternate_af1(cs);
+            let rx = gpioa.pa10.into_alternate_af1(cs);
 
-        // Initialise ADC
-        let adc = hal::adc::Adc::new(p.ADC);
+            // Initialiase UART
+            let (mut tx, _) =
+                hal::serial::Serial::usart1(p.USART1, (tx, rx), 115_200.bps(), &mut rcc).split();
 
-        // Output a friendly greeting
-        tx.write_str("\n\rThis ADC example will read various values using the ADC and print them out to the serial terminal\r\n").ok();
+            // Initialise ADC
+            let adc = hal::adc::Adc::new(p.ADC, &mut rcc);
 
-        // Move all components under Mutex supervision
-        cortex_m::interrupt::free(move |cs| {
+            // Output a friendly greeting
+            tx.write_str("\n\rThis ADC example will read various values using the ADC and print them out to the serial terminal\r\n").ok();
+
+            // Move all components under Mutex supervision
             *SHARED.borrow(cs).borrow_mut() = Some(Shared { adc, tx });
         });
     }

examples/blinky.rs

@@ -14,21 +14,26 @@ use cortex_m_rt::entry;
 #[entry]
 fn main() -> ! {
     if let Some(p) = stm32::Peripherals::take() {
-        let gpioa = p.GPIOA.split();
-
-        /* (Re-)configure PA1 as output */
-        let mut led = gpioa.pa1.into_push_pull_output();
-
-        loop {
-            /* Turn PA1 on a million times in a row */
-            for _ in 0..1_000_000 {
-                led.set_high();
-            }
-            /* Then turn PA1 off a million times in a row */
-            for _ in 0..1_000_000 {
-                led.set_low();
+        cortex_m::interrupt::free(move |cs| {
+            let mut flash = p.FLASH;
+            let mut rcc = p.RCC.configure().sysclk(8.mhz()).freeze(&mut flash);
+
+            let gpioa = p.GPIOA.split(&mut rcc);
+
+            /* (Re-)configure PA1 as output */
+            let mut led = gpioa.pa1.into_push_pull_output(cs);
+
+            loop {
+                /* Turn PA1 on a million times in a row */
+                for _ in 0..1_000_000 {
+                    led.set_high();
+                }
+                /* Then turn PA1 off a million times in a row */
+                for _ in 0..1_000_000 {
+                    led.set_low();
+                }
             }
-        }
+        });
     }
 
     loop {

examples/blinky_adc.rs

@@ -18,36 +18,35 @@ use cortex_m_rt::entry;
 #[entry]
 fn main() -> ! {
     if let (Some(p), Some(cp)) = (stm32::Peripherals::take(), Peripherals::take()) {
-        let gpioa = p.GPIOA.split();
+        cortex_m::interrupt::free(move |cs| {
+            let mut flash = p.FLASH;
+            let mut rcc = p.RCC.configure().sysclk(8.mhz()).freeze(&mut flash);
 
-        /* (Re-)configure PA1 as output */
-        let mut led = gpioa.pa1.into_push_pull_output();
+            let gpioa = p.GPIOA.split(&mut rcc);
 
-        /* (Re-)configure PA0 as analog in */
-        let mut an_in = gpioa.pa0.into_analog();
+            /* (Re-)configure PA1 as output */
+            let mut led = gpioa.pa1.into_push_pull_output(cs);
 
-        /* Constrain clocking registers */
-        let rcc = p.RCC.constrain();
+            /* (Re-)configure PA0 as analog in */
+            let mut an_in = gpioa.pa0.into_analog(cs);
 
-        /* Configure clock to 8 MHz (i.e. the default) and freeze it */
-        let clocks = rcc.cfgr.sysclk(8.mhz()).freeze();
+            /* Get delay provider */
+            let mut delay = Delay::new(cp.SYST, &rcc);
 
-        /* Get delay provider */
-        let mut delay = Delay::new(cp.SYST, clocks);
+            let mut adc = Adc::new(p.ADC, &mut rcc);
 
-        let mut adc = Adc::new(p.ADC);
+            loop {
+                led.toggle();
 
-        loop {
-            led.toggle();
+                let val: u16 = adc.read(&mut an_in).unwrap();
 
-            let val: u16 = adc.read(&mut an_in).unwrap();
+                /* shift the value right by 3, same as divide by 8, reduces
+                the 0-4095 range into something approximating 1-512 */
+                let time: u16 = (val >> 3) + 1;
 
-            /* shift the value right by 3, same as divide by 8, reduces
-            the 0-4095 range into something approximating 1-512 */
-            let time: u16 = (val >> 3) + 1;
-
-            delay.delay_ms(time);
-        }
+                delay.delay_ms(time);
+            }
+        });
     }
 
     loop {

examples/blinky_delay.rs

@@ -16,24 +16,23 @@ use cortex_m_rt::entry;
 #[entry]
 fn main() -> ! {
     if let (Some(p), Some(cp)) = (stm32::Peripherals::take(), Peripherals::take()) {
-        let gpioa = p.GPIOA.split();
+        cortex_m::interrupt::free(move |cs| {
+            let mut flash = p.FLASH;
+            let mut rcc = p.RCC.configure().sysclk(8.mhz()).freeze(&mut flash);
 
-        /* (Re-)configure PA1 as output */
-        let mut led = gpioa.pa1.into_push_pull_output();
+            let gpioa = p.GPIOA.split(&mut rcc);
 
-        /* Constrain clocking registers */
-        let rcc = p.RCC.constrain();
+            /* (Re-)configure PA1 as output */
+            let mut led = gpioa.pa1.into_push_pull_output(cs);
 
-        /* Configure clock to 8 MHz (i.e. the default) and freeze it */
-        let clocks = rcc.cfgr.sysclk(8.mhz()).freeze();
+            /* Get delay provider */
+            let mut delay = Delay::new(cp.SYST, &rcc);
 
-        /* Get delay provider */
-        let mut delay = Delay::new(cp.SYST, clocks);
-
-        loop {
-            led.toggle();
-            delay.delay_ms(1_000_u16);
-        }
+            loop {
+                led.toggle();
+                delay.delay_ms(1_000_u16);
+            }
+        });
     }
 
     loop {

examples/blinky_multiple.rs

@@ -16,37 +16,36 @@ use cortex_m_rt::entry;
 #[entry]
 fn main() -> ! {
     if let (Some(p), Some(cp)) = (stm32::Peripherals::take(), Peripherals::take()) {
-        let gpioa = p.GPIOA.split();
-        let gpiob = p.GPIOB.split();
-
-        /* (Re-)configure PA1 as output */
-        let led1 = gpioa.pa1.into_push_pull_output();
-
-        /* (Re-)configure PB1 as output */
-        let led2 = gpiob.pb1.into_push_pull_output();
-
-        /* Constrain clocking registers */
-        let rcc = p.RCC.constrain();
-
-        /* Configure clock to 8 MHz (i.e. the default) and freeze it */
-        let clocks = rcc.cfgr.sysclk(8.mhz()).freeze();
-
-        /* Get delay provider */
-        let mut delay = Delay::new(cp.SYST, clocks);
-
-        /* Store them together */
-        let mut leds = [led1.downgrade(), led2.downgrade()];
-        loop {
-            for l in &mut leds {
-                l.set_high();
-            }
-            delay.delay_ms(1_000_u16);
-
-            for l in &mut leds {
-                l.set_low();
+        cortex_m::interrupt::free(move |cs| {
+            let mut flash = p.FLASH;
+            let mut rcc = p.RCC.configure().sysclk(8.mhz()).freeze(&mut flash);
+
+            let gpioa = p.GPIOA.split(&mut rcc);
+            let gpiob = p.GPIOB.split(&mut rcc);
+
+            /* (Re-)configure PA1 as output */
+            let led1 = gpioa.pa1.into_push_pull_output(cs);
+
+            /* (Re-)configure PB1 as output */
+            let led2 = gpiob.pb1.into_push_pull_output(cs);
+
+            /* Get delay provider */
+            let mut delay = Delay::new(cp.SYST, &rcc);
+
+            /* Store them together */
+            let mut leds = [led1.downgrade(), led2.downgrade()];
+            loop {
+                for l in &mut leds {
+                    l.set_high();
+                }
+                delay.delay_ms(1_000_u16);
+
+                for l in &mut leds {
+                    l.set_low();
+                }
+                delay.delay_ms(1_000_u16);
             }
-            delay.delay_ms(1_000_u16);
-        }
+        });
     }
 
     loop {

examples/blinky_timer.rs

@@ -17,22 +17,21 @@ use nb::block;
 #[entry]
 fn main() -> ! {
     if let Some(p) = stm32::Peripherals::take() {
-        let gpioa = p.GPIOA.split();
-        /* (Re-)configure PA1 as output */
-        let mut led = gpioa.pa1.into_push_pull_output();
+        cortex_m::interrupt::free(move |cs| {
+            let mut flash = p.FLASH;
+            let mut rcc = p.RCC.configure().sysclk(8.mhz()).freeze(&mut flash);
 
-        /* Constrain clocking registers */
-        let rcc = p.RCC.constrain();
+            let gpioa = p.GPIOA.split(&mut rcc);
+            /* (Re-)configure PA1 as output */
+            let mut led = gpioa.pa1.into_push_pull_output(cs);
 
-        /* Configure clock to 8 MHz (i.e. the default) and freeze it */
-        let clocks = rcc.cfgr.sysclk(8.mhz()).freeze();
+            let mut timer = Timer::tim1(p.TIM1, Hertz(1), &mut rcc);
 
-        let mut timer = Timer::tim1(p.TIM1, Hertz(1), clocks);
-
-        loop {
-            led.toggle();
-            block!(timer.wait()).ok();
-        }
+            loop {
+                led.toggle();
+                block!(timer.wait()).ok();
+            }
+        });
     }
 
     loop {

examples/flash_systick.rs

@@ -23,32 +23,34 @@ static GPIO: Mutex<RefCell<Option<gpioa::PA1<Output<PushPull>>>>> = Mutex::new(R
 #[entry]
 fn main() -> ! {
     if let (Some(p), Some(cp)) = (stm32::Peripherals::take(), Peripherals::take()) {
-        let gpioa = p.GPIOA.split();
-        let rcc = p.RCC.constrain();
-        let _ = rcc.cfgr.sysclk(48.mhz()).freeze();
-        let mut syst = cp.SYST;
+        cortex_m::interrupt::free(move |cs| {
+            let mut flash = p.FLASH;
+            let mut rcc = p.RCC.configure().sysclk(48.mhz()).freeze(&mut flash);
 
-        /* (Re-)configure PA1 as output */
-        let led = gpioa.pa1.into_push_pull_output();
+            let gpioa = p.GPIOA.split(&mut rcc);
+
+            let mut syst = cp.SYST;
+
+            /* (Re-)configure PA1 as output */
+            let led = gpioa.pa1.into_push_pull_output(cs);
 
-        cortex_m::interrupt::free(move |cs| {
             *GPIO.borrow(cs).borrow_mut() = Some(led);
-        });
 
-        /* Initialise SysTick counter with a defined value */
-        unsafe { syst.cvr.write(1) };
+            /* Initialise SysTick counter with a defined value */
+            unsafe { syst.cvr.write(1) };
 
-        /* Set source for SysTick counter, here full operating frequency (== 8MHz) */
-        syst.set_clock_source(Core);
+            /* Set source for SysTick counter, here full operating frequency (== 8MHz) */
+            syst.set_clock_source(Core);
 
-        /* Set reload value, i.e. timer delay 48 MHz/4 Mcounts == 12Hz or 83ms */
-        syst.set_reload(4_000_000 - 1);
+            /* Set reload value, i.e. timer delay 48 MHz/4 Mcounts == 12Hz or 83ms */
+            syst.set_reload(4_000_000 - 1);
 
-        /* Start counter */
-        syst.enable_counter();
+            /* Start counter */
+            syst.enable_counter();
 
-        /* Start interrupt generation */
-        syst.enable_interrupt();
+            /* Start interrupt generation */
+            syst.enable_interrupt();
+        });
     }
 
     loop {