improve UART impl

Reviewed-on: #32

Cargo.toml

@@ -41,4 +41,4 @@ debug-assertions = false # <-
 lto = true
 opt-level = 'z'            # <-
 overflow-checks = false  # <-
-# strip = true  # Automatically strip symbols from the binary.
+strip = true  # Automatically strip symbols from the binary.

README.md

@@ -99,9 +99,9 @@ example.
 
 ### Using VS Code
 
-Assuming a working debug connection to your VA108xx board, you can debug using VS Code with
-the [`Cortex-Debug` plugin](https://marketplace.visualstudio.com/items?itemName=marus25.cortex-debug). Please make sure that
-[`objdump-multiarch` and `nm-multiarch`](https://forums.raspberrypi.com/viewtopic.php?t=333146)
+Assuming a working debug connection to your VA416xx board, you can debug using VS Code with
+the [`Cortex-Debug` plugin](https://marketplace.visualstudio.com/items?itemName=marus25.cortex-debug).
+Please make sure that [`objdump-multiarch` and `nm-multiarch`](https://forums.raspberrypi.com/viewtopic.php?t=333146)
 are installed as well.
 
 Some sample configuration files for VS code were provided and can be used by running

bootloader/Cargo.toml

@@ -8,8 +8,15 @@ cortex-m = "0.7"
 cortex-m-rt = "0.7"
 embedded-hal = "1"
 panic-rtt-target = { version = "0.1.3" }
+panic-halt = { version = "0.2" }
 rtt-target = { version = "0.5" }
 crc = "3"
+static_assertions = "1"
 
 [dependencies.va416xx-hal]
 path = "../va416xx-hal"
+features = ["va41630"]
+
+[features]
+default = []
+rtt-panic = []

bootloader/README.md

@@ -12,11 +12,11 @@ The bootloader uses the following memory map:
 | 0x0 | Bootloader start | code up to 0x3FFC bytes |
 | 0x3FFC | Bootloader CRC | word |
 | 0x4000 | App image A start | code up to 0x1DFFC (~120K) bytes |
-| 0x21FFC | App image A CRC check length | word |
-| 0x21FFE | App image A CRC check value | word |
+| 0x21FF8 | App image A CRC check length | word |
+| 0x21FFC | App image A CRC check value | word |
 | 0x22000 | App image B start | code up to 0x1DFFC (~120K) bytes |
-| 0x3FFFC | App image B CRC check length | word |
-| 0x3FFFE | App image B CRC check value | word |
+| 0x3FFF8 | App image B CRC check length | word |
+| 0x3FFFC | App image B CRC check value | word |
 | 0x40000 | End of NVM | end  |
 
 ## Additional Information

bootloader/src/main.rs

@@ -1,17 +1,5 @@
 //! Vorago bootloader which can boot from two images.
 //!
-//! Bootloader memory map
-//!
-//! * <0x0>     Bootloader start                         <code up to 0x3FFE bytes>
-//! * <0x3FFE>  Bootloader CRC                           <halfword>
-//! * <0x4000>  App image A start                        <code up to 0x1DFFC (~120K) bytes>
-//! * <0x21FFC> App image A CRC check length             <halfword>
-//! * <0x21FFE> App image A CRC check value              <halfword>
-//! * <0x22000> App image B start                        <code up to 0x1DFFC (~120K) bytes>
-//! * <0x3FFFC> App image B CRC check length             <halfword>
-//! * <0x3FFFE> App image B CRC check value              <halfword>
-//! * <0x40000>                                          <end>
-//!
 //! As opposed to the Vorago example code, this bootloader assumes a 40 MHz external clock
 //! but does not scale that clock up.
 #![no_main]
@@ -19,6 +7,9 @@
 
 use cortex_m_rt::entry;
 use crc::{Crc, CRC_32_ISO_HDLC};
+#[cfg(not(feature = "rtt-panic"))]
+use panic_halt as _;
+#[cfg(feature = "rtt-panic")]
 use panic_rtt_target as _;
 use rtt_target::{rprintln, rtt_init_print};
 use va416xx_hal::{
@@ -42,23 +33,42 @@ const DEBUG_PRINTOUTS: bool = true;
 // self-flash itself. It is recommended that you use a tool like probe-rs, Keil IDE, or a flash
 // loader to boot a bootloader without this feature.
 const FLASH_SELF: bool = false;
+// Useful for debugging and see what the bootloader is doing. Enabled currently, because
+// the binary stays small enough.
+const RTT_PRINTOUT: bool = true;
 
 // Important bootloader addresses and offsets, vector table information.
 
+const NVM_SIZE: u32 = 0x40000;
+
 const BOOTLOADER_START_ADDR: u32 = 0x0;
+const BOOTLOADER_CRC_ADDR: u32 = BOOTLOADER_END_ADDR - 4;
 const BOOTLOADER_END_ADDR: u32 = 0x4000;
-const BOOTLOADER_CRC_ADDR: u32 = 0x3FFC;
-const APP_A_START_ADDR: u32 = 0x4000;
-pub const APP_A_END_ADDR: u32 = 0x22000;
-// The actual size of the image which is relevant for CRC calculation.
-const APP_A_SIZE_ADDR: u32 = 0x21FF8;
-const APP_A_CRC_ADDR: u32 = 0x21FFC;
-const APP_B_START_ADDR: u32 = 0x22000;
-pub const APP_B_END_ADDR: u32 = 0x40000;
-// The actual size of the image which is relevant for CRC calculation.
-const APP_B_SIZE_ADDR: u32 = 0x3FFF8;
-const APP_B_CRC_ADDR: u32 = 0x3FFFC;
-pub const APP_IMG_SZ: u32 = 0x1E000;
+
+// 0x4000
+const APP_A_START_ADDR: u32 = BOOTLOADER_END_ADDR;
+// The actual size of the image which is relevant for CRC calculation will be store at this
+// address.
+// 0x21FF8
+const APP_A_SIZE_ADDR: u32 = APP_B_END_ADDR - 8;
+// 0x21FFC
+const APP_A_CRC_ADDR: u32 = APP_B_END_ADDR - 4;
+pub const APP_A_END_ADDR: u32 = APP_B_END_ADDR - BOOTLOADER_END_ADDR / 2;
+
+//  0x22000
+const APP_B_START_ADDR: u32 = APP_A_END_ADDR;
+// The actual size of the image which is relevant for CRC calculation will be stored at this
+// address.
+// 0x3FFF8
+const APP_B_SIZE_ADDR: u32 = APP_B_END_ADDR - 8;
+// 0x3FFFC
+const APP_B_CRC_ADDR: u32 = APP_B_END_ADDR - 4;
+// 0x40000
+pub const APP_B_END_ADDR: u32 = NVM_SIZE;
+
+pub const APP_IMG_SZ: u32 = APP_B_END_ADDR - APP_A_START_ADDR / 2;
+
+static_assertions::const_assert!((APP_B_END_ADDR - BOOTLOADER_END_ADDR) % 2 == 0);
 
 pub const VECTOR_TABLE_OFFSET: u32 = 0x0;
 pub const VECTOR_TABLE_LEN: u32 = 0x350;
@@ -88,8 +98,10 @@ impl WdtInterface for OptWdt {
 
 #[entry]
 fn main() -> ! {
+    if RTT_PRINTOUT {
         rtt_init_print!();
         rprintln!("-- VA416xx bootloader --");
+    }
     let mut dp = pac::Peripherals::take().unwrap();
     let cp = cortex_m::Peripherals::take().unwrap();
     // Disable ROM protection.
@@ -133,20 +145,26 @@ fn main() -> ! {
         nvm.write_data(0x0, &first_four_bytes);
         nvm.write_data(0x4, bootloader_data);
         if let Err(e) = nvm.verify_data(0x0, &first_four_bytes) {
+            if RTT_PRINTOUT {
                 rprintln!("verification of self-flash to NVM failed: {:?}", e);
             }
+        }
         if let Err(e) = nvm.verify_data(0x4, bootloader_data) {
+            if RTT_PRINTOUT {
                 rprintln!("verification of self-flash to NVM failed: {:?}", e);
             }
+        }
 
         nvm.write_data(BOOTLOADER_CRC_ADDR, &bootloader_crc.to_be_bytes());
         if let Err(e) = nvm.verify_data(BOOTLOADER_CRC_ADDR, &bootloader_crc.to_be_bytes()) {
+            if RTT_PRINTOUT {
                 rprintln!(
                     "error: CRC verification for bootloader self-flash failed: {:?}",
                     e
                 );
             }
         }
+    }
 
     // Check bootloader's CRC (and write it if blank)
     check_own_crc(&opt_wdt, &nvm, &cp);
@@ -156,7 +174,7 @@ fn main() -> ! {
     } else if check_app_crc(AppSel::B, &opt_wdt) {
         boot_app(AppSel::B, &cp)
     } else {
-        if DEBUG_PRINTOUTS {
+        if DEBUG_PRINTOUTS && RTT_PRINTOUT {
             rprintln!("both images corrupt! booting image A");
         }
         // TODO: Shift a CCSDS packet out to inform host/OBC about image corruption.
@@ -184,7 +202,7 @@ fn check_own_crc(wdt: &OptWdt, nvm: &Nvm, cp: &cortex_m::Peripherals) {
     let crc_calc = digest.finalize();
     wdt.feed();
     if crc_exp == 0x0000 || crc_exp == 0xffff {
-        if DEBUG_PRINTOUTS {
+        if DEBUG_PRINTOUTS && RTT_PRINTOUT {
             rprintln!("BL CRC blank - prog new CRC");
         }
         // Blank CRC, write it to NVM.
@@ -194,7 +212,7 @@ fn check_own_crc(wdt: &OptWdt, nvm: &Nvm, cp: &cortex_m::Peripherals) {
         // cortex_m::peripheral::SCB::sys_reset();
     } else if crc_exp != crc_calc {
         // Bootloader is corrupted. Try to run App A.
-        if DEBUG_PRINTOUTS {
+        if DEBUG_PRINTOUTS && RTT_PRINTOUT {
             rprintln!(
                 "bootloader CRC corrupt, read {} and expected {}. booting image A immediately",
                 crc_calc,
@@ -217,7 +235,7 @@ fn read_four_bytes_at_addr_zero(buf: &mut [u8; 4]) {
     }
 }
 fn check_app_crc(app_sel: AppSel, wdt: &OptWdt) -> bool {
-    if DEBUG_PRINTOUTS {
+    if DEBUG_PRINTOUTS && RTT_PRINTOUT {
         rprintln!("Checking image {:?}", app_sel);
     }
     if app_sel == AppSel::A {
@@ -237,7 +255,9 @@ fn check_app_given_addr(
     let image_size = unsafe { (image_size_addr as *const u32).read_unaligned().to_be() };
     // Sanity check.
     if image_size > APP_A_END_ADDR - APP_A_START_ADDR - 8 {
+        if RTT_PRINTOUT {
             rprintln!("detected invalid app size {}", image_size);
+        }
         return false;
     }
     wdt.feed();
@@ -252,7 +272,7 @@ fn check_app_given_addr(
 }
 
 fn boot_app(app_sel: AppSel, cp: &cortex_m::Peripherals) -> ! {
-    if DEBUG_PRINTOUTS {
+    if DEBUG_PRINTOUTS && RTT_PRINTOUT {
         rprintln!("booting app {:?}", app_sel);
     }
     let clkgen = unsafe { pac::Clkgen::steal() };

examples/embassy/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2021"
 cortex-m = { version = "0.7", features = ["critical-section-single-core"] }
 cortex-m-rt = "0.7"
 embedded-hal = "1"
+embedded-io = "0.6"
 
 rtt-target = { version = "0.5" }
 panic-rtt-target = { version = "0.1" }
@@ -16,6 +17,10 @@ embassy-sync = { version = "0.6.0" }
 embassy-time = { version = "0.3.2" }
 embassy-time-driver = { version = "0.1" }
 
+[dependencies.ringbuf]
+version = "0.4"
+default-features = false
+
 [dependencies.once_cell]
 version = "1"
 default-features = false

examples/embassy/src/bin/uart-echo-with-irq.rs

@@ -0,0 +1,161 @@
+//! This is an example of using the UART HAL abstraction with the IRQ support and embassy.
+//!
+//! It uses the UART0 for communication with another MCU or a host computer (recommended).
+//! You can connect a USB-to-Serial converter to the UART0 pins and then use a serial terminal
+//! application like picocom to send data to the microcontroller, which should be echoed
+//! back to the sender.
+//!
+//! This application uses the interrupt support of the VA416xx to read the data arriving
+//! on the UART without requiring polling.
+#![no_std]
+#![no_main]
+use core::cell::RefCell;
+
+use embassy_example::EXTCLK_FREQ;
+use embassy_executor::Spawner;
+use embassy_sync::blocking_mutex::raw::CriticalSectionRawMutex;
+use embassy_sync::blocking_mutex::Mutex;
+use embassy_time::{Duration, Ticker};
+use embedded_hal::digital::StatefulOutputPin;
+use embedded_io::Write;
+use panic_rtt_target as _;
+use ringbuf::{
+    traits::{Consumer, Observer, Producer},
+    StaticRb,
+};
+use rtt_target::{rprintln, rtt_init_print};
+use va416xx_hal::{
+    gpio::{OutputReadablePushPull, Pin, PinsG, PG5},
+    pac::{self, interrupt},
+    prelude::*,
+    time::Hertz,
+    uart,
+};
+
+pub type SharedUart = Mutex<CriticalSectionRawMutex, RefCell<Option<uart::RxWithIrq<pac::Uart0>>>>;
+static RX: SharedUart = Mutex::new(RefCell::new(None));
+
+const BAUDRATE: u32 = 115200;
+
+// Ring buffer size.
+const RING_BUF_SIZE: usize = 2048;
+
+pub type SharedRingBuf =
+    Mutex<CriticalSectionRawMutex, RefCell<Option<StaticRb<u8, RING_BUF_SIZE>>>>;
+// Ring buffers to handling variable sized telemetry
+static RINGBUF: SharedRingBuf = Mutex::new(RefCell::new(None));
+
+// See https://embassy.dev/book/#_sharing_using_a_mutex for background information about sharing
+// a peripheral with embassy.
+#[embassy_executor::main]
+async fn main(spawner: Spawner) {
+    rtt_init_print!();
+    rprintln!("VA416xx UART-Embassy Example");
+
+    let mut dp = pac::Peripherals::take().unwrap();
+
+    // Initialize the systick interrupt & obtain the token to prove that we did
+    // Use the external clock connected to XTAL_N.
+    let clocks = dp
+        .clkgen
+        .constrain()
+        .xtal_n_clk_with_src_freq(Hertz::from_raw(EXTCLK_FREQ))
+        .freeze(&mut dp.sysconfig)
+        .unwrap();
+    // Safety: Only called once here.
+    unsafe {
+        embassy_example::init(
+            &mut dp.sysconfig,
+            &dp.irq_router,
+            dp.tim15,
+            dp.tim14,
+            &clocks,
+        )
+    };
+
+    let portg = PinsG::new(&mut dp.sysconfig, dp.portg);
+
+    let tx = portg.pg0.into_funsel_1();
+    let rx = portg.pg1.into_funsel_1();
+
+    let uart0 = uart::Uart::new(
+        dp.uart0,
+        (tx, rx),
+        Hertz::from_raw(BAUDRATE),
+        &mut dp.sysconfig,
+        &clocks,
+    );
+    let (mut tx, rx) = uart0.split();
+    let mut rx = rx.to_rx_with_irq();
+    rx.start();
+    RX.lock(|static_rx| {
+        static_rx.borrow_mut().replace(rx);
+    });
+    RINGBUF.lock(|static_rb| {
+        static_rb.borrow_mut().replace(StaticRb::default());
+    });
+
+    let led = portg.pg5.into_readable_push_pull_output();
+    let mut ticker = Ticker::every(Duration::from_millis(50));
+    let mut processing_buf: [u8; RING_BUF_SIZE] = [0; RING_BUF_SIZE];
+    let mut read_bytes = 0;
+    spawner.spawn(blinky(led)).expect("failed to spawn blinky");
+    loop {
+        RINGBUF.lock(|static_rb| {
+            let mut rb_borrow = static_rb.borrow_mut();
+            let rb_mut = rb_borrow.as_mut().unwrap();
+            read_bytes = rb_mut.occupied_len();
+            rb_mut.pop_slice(&mut processing_buf[0..read_bytes]);
+        });
+        // Simply send back all received data.
+        tx.write_all(&processing_buf[0..read_bytes])
+            .expect("sending back read data failed");
+        ticker.next().await;
+    }
+}
+
+#[embassy_executor::task]
+async fn blinky(mut led: Pin<PG5, OutputReadablePushPull>) {
+    let mut ticker = Ticker::every(Duration::from_millis(500));
+    loop {
+        led.toggle().ok();
+        ticker.next().await;
+    }
+}
+
+#[interrupt]
+#[allow(non_snake_case)]
+fn UART0_RX() {
+    let mut buf: [u8; 16] = [0; 16];
+    let mut read_len: usize = 0;
+    let mut errors = None;
+    RX.lock(|static_rx| {
+        let mut rx_borrow = static_rx.borrow_mut();
+        let rx_mut_ref = rx_borrow.as_mut().unwrap();
+        let result = rx_mut_ref.irq_handler(&mut buf);
+        read_len = result.bytes_read;
+        if result.errors.is_some() {
+            errors = result.errors;
+        }
+    });
+    let mut ringbuf_full = false;
+    if read_len > 0 {
+        // Send the received buffer to the main thread for processing via a ring buffer.
+        RINGBUF.lock(|static_rb| {
+            let mut rb_borrow = static_rb.borrow_mut();
+            let rb_mut_ref = rb_borrow.as_mut().unwrap();
+            if rb_mut_ref.vacant_len() < read_len {
+                ringbuf_full = true;
+                for _ in rb_mut_ref.pop_iter() {}
+            }
+            rb_mut_ref.push_slice(&buf[0..read_len]);
+        });
+    }
+
+    if errors.is_some() {
+        rprintln!("UART error: {:?}", errors);
+    }
+    if ringbuf_full {
+        rprintln!("ringbuffer is full, deleted oldest data");
+    }
+}

examples/embassy/src/lib.rs

@@ -1,4 +1,6 @@
 #![no_std]
 pub mod time_driver;
 
+pub const EXTCLK_FREQ: u32 = 40_000_000;
+
 pub use time_driver::init;

examples/embassy/src/main.rs

@@ -1,5 +1,6 @@
 #![no_std]
 #![no_main]
+use embassy_example::EXTCLK_FREQ;
 use embassy_executor::Spawner;
 use embassy_time::{Duration, Instant, Ticker};
 use embedded_hal::digital::StatefulOutputPin;
@@ -7,8 +8,6 @@ use panic_rtt_target as _;
 use rtt_target::{rprintln, rtt_init_print};
 use va416xx_hal::{gpio::PinsG, pac, prelude::*, time::Hertz};
 
-const EXTCLK_FREQ: u32 = 40_000_000;
-
 // main is itself an async function.
 #[embassy_executor::main]
 async fn main(_spawner: Spawner) {

examples/embassy/src/time_driver.rs

@@ -17,7 +17,7 @@ use va416xx_hal::{
     enable_interrupt,
     irq_router::enable_and_init_irq_router,
     pac::{self, interrupt},
-    pwm::{assert_tim_reset_for_two_cycles, enable_tim_clk, ValidTim},
+    timer::{assert_tim_reset_for_two_cycles, enable_tim_clk, ValidTim},
 };
 
 pub type TimekeeperClk = pac::Tim15;

examples/rtic/src/main.rs

@@ -2,8 +2,13 @@
 #![no_main]
 #![no_std]
 
+use va416xx_hal::time::Hertz;
+
+const EXTCLK_FREQ: Hertz = Hertz::from_raw(40_000_000);
+
 #[rtic::app(device = pac, dispatchers = [U1, U2, U3])]
 mod app {
+    use super::*;
     use cortex_m::asm;
     use embedded_hal::digital::StatefulOutputPin;
     use panic_rtt_target as _;
@@ -13,6 +18,7 @@ mod app {
     use va416xx_hal::{
         gpio::{OutputReadablePushPull, Pin, PinsG, PG5},
         pac,
+        prelude::*,
     };
 
     #[local]
@@ -23,14 +29,22 @@ mod app {
     #[shared]
     struct Shared {}
 
-    rtic_monotonics::systick_monotonic!(Mono, 10_000);
+    rtic_monotonics::systick_monotonic!(Mono, 1_000);
 
     #[init]
-    fn init(_ctx: init::Context) -> (Shared, Local) {
+    fn init(mut cx: init::Context) -> (Shared, Local) {
         rtt_init_default!();
-        rprintln!("-- Vorago RTIC template --");
-        let mut dp = pac::Peripherals::take().unwrap();
-        let portg = PinsG::new(&mut dp.sysconfig, dp.portg);
+        rprintln!("-- Vorago RTIC example application --");
+        // Use the external clock connected to XTAL_N.
+        let clocks = cx
+            .device
+            .clkgen
+            .constrain()
+            .xtal_n_clk_with_src_freq(EXTCLK_FREQ)
+            .freeze(&mut cx.device.sysconfig)
+            .unwrap();
+        Mono::start(cx.core.SYST, clocks.sysclk().raw());
+        let portg = PinsG::new(&mut cx.device.sysconfig, cx.device.portg);
         let led = portg.pg5.into_readable_push_pull_output();
         blinky::spawn().ok();
         (Shared {}, Local { led })

examples/simple/examples/dma.rs

@@ -12,7 +12,7 @@ use rtt_target::{rprintln, rtt_init_print};
 use simple_examples::peb1;
 use va416xx_hal::dma::{Dma, DmaCfg, DmaChannel, DmaCtrlBlock};
 use va416xx_hal::irq_router::enable_and_init_irq_router;
-use va416xx_hal::pwm::CountdownTimer;
+use va416xx_hal::timer::CountdownTimer;
 use va416xx_hal::{
     pac::{self, interrupt},
     prelude::*,

examples/simple/examples/pwm.rs

@@ -11,7 +11,8 @@ use va416xx_hal::{
     gpio::PinsA,
     pac,
     prelude::*,
-    pwm::{self, get_duty_from_percent, CountdownTimer, PwmA, PwmB, ReducedPwmPin},
+    pwm::{self, get_duty_from_percent, PwmA, PwmB, ReducedPwmPin},
+    timer::CountdownTimer,
 };
 
 #[entry]

examples/simple/examples/spi.rs

@@ -3,13 +3,12 @@
 //! If you do not use the loopback mode, MOSI and MISO need to be tied together on the board.
 #![no_main]
 #![no_std]
-
 use cortex_m_rt::entry;
 use embedded_hal::spi::{Mode, SpiBus, MODE_0};
 use panic_rtt_target as _;
 use rtt_target::{rprintln, rtt_init_print};
 use simple_examples::peb1;
-use va416xx_hal::spi::{clk_div_for_target_clock, Spi, TransferConfig};
+use va416xx_hal::spi::{Spi, SpiClkConfig};
 use va416xx_hal::{
     gpio::{PinsB, PinsC},
     pac,
@@ -22,9 +21,8 @@ use va416xx_hal::{
 pub enum ExampleSelect {
     // Enter loopback mode. It is not necessary to tie MOSI/MISO together for this
     Loopback,
-    // Send a test buffer and print everything received. You need to tie together MOSI/MISO in this
-    // mode.
-    TestBuffer,
+    // You need to tie together MOSI/MISO in this mode.
+    MosiMisoTiedTogether,
 }
 
 const EXAMPLE_SEL: ExampleSelect = ExampleSelect::Loopback;
@@ -50,21 +48,23 @@ fn main() -> ! {
 
     let pins_b = PinsB::new(&mut dp.sysconfig, dp.portb);
     let pins_c = PinsC::new(&mut dp.sysconfig, dp.portc);
-    // Configure SPI1 pins.
+    // Configure SPI0 pins.
     let (sck, miso, mosi) = (
         pins_b.pb15.into_funsel_1(),
         pins_c.pc0.into_funsel_1(),
         pins_c.pc1.into_funsel_1(),
     );
 
-    let mut spi_cfg = SpiConfig::default().clk_div(
-        clk_div_for_target_clock(Hertz::from_raw(SPI_SPEED_KHZ), &clocks)
+    let mut spi_cfg = SpiConfig::default()
+        .clk_cfg(
+            SpiClkConfig::from_clk(Hertz::from_raw(SPI_SPEED_KHZ), &clocks)
                 .expect("invalid target clock"),
-    );
+        )
+        .mode(SPI_MODE)
+        .blockmode(BLOCKMODE);
     if EXAMPLE_SEL == ExampleSelect::Loopback {
         spi_cfg = spi_cfg.loopback(true)
     }
-    let transfer_cfg = TransferConfig::new_no_hw_cs(None, Some(SPI_MODE), BLOCKMODE, false);
     // Create SPI peripheral.
     let mut spi0 = Spi::new(
         &mut dp.sysconfig,
@@ -72,29 +72,27 @@ fn main() -> ! {
         dp.spi0,
         (sck, miso, mosi),
         spi_cfg,
-        Some(&transfer_cfg.downgrade()),
-    )
-    .expect("creating SPI peripheral failed");
+    );
     spi0.set_fill_word(FILL_WORD);
     loop {
-        let mut tx_buf: [u8; 3] = [1, 2, 3];
-        let mut rx_buf: [u8; 3] = [0; 3];
-        // Can't really verify correct reply here.
-        spi0.write(&[0x42]).expect("write failed");
-        // Need small delay.. otherwise we will read back the sent byte (which we don't want here).
-        // The write function will return as soon as all bytes were shifted out, ignoring the
-        // reply bytes.
-        delay_sysclk.delay_us(50);
-        // Because of the loopback mode, we should get back the fill word here.
-        spi0.read(&mut rx_buf[0..1]).unwrap();
-        assert_eq!(rx_buf[0], FILL_WORD);
+        let tx_buf: [u8; 4] = [1, 2, 3, 0];
+        let mut rx_buf: [u8; 4] = [0; 4];
+        // Can't really verify correct behaviour here. Just verify nothing crazy happens or it hangs up.
+        spi0.write(&[0x42, 0x43]).expect("write failed");
 
-        spi0.transfer_in_place(&mut tx_buf)
+        // Can't really verify correct behaviour here. Just verify nothing crazy happens or it hangs up.
+        spi0.read(&mut rx_buf[0..2]).unwrap();
+
+        // If the pins are tied together, we should received exactly what we send.
+
+        let mut inplace_buf = tx_buf;
+        spi0.transfer_in_place(&mut inplace_buf)
             .expect("SPI transfer_in_place failed");
-        assert_eq!([1, 2, 3], tx_buf);
+        assert_eq!([1, 2, 3, 0], inplace_buf);
+
         spi0.transfer(&mut rx_buf, &tx_buf)
             .expect("SPI transfer failed");
-        assert_eq!(rx_buf, tx_buf);
+        assert_eq!(rx_buf, [1, 2, 3, 0]);
         delay_sysclk.delay_ms(500);
     }
 }

flashloader/README.md

@@ -6,12 +6,18 @@ a simple PUS (CCSDS) interface to update the software. It also provides a Python
 called the `image-loader.py` which can be used to upload compiled images to the flashloader
 application to write them to the NVM.
 
+Please note that the both the application and the image loader are tailored towards usage
+with the [bootloader provided by this repository](https://egit.irs.uni-stuttgart.de/rust/va416xx-rs/src/branch/main/bootloader).
+
 The software can quickly be adapted to interface with a real primary on-board software instead of
 the Python script provided here to upload images because it uses a low-level CCSDS based packet
 interface.
 
 ## Using the Python image loader
 
+The Python image loader communicates with the Rust flashload application using a dedicated serial
+port with a baudrate of 115200.
+
 It is recommended to run the script in a dedicated virtual environment. For example, on UNIX
 systems you can use `python3 -m venv venv` and then `source venv/bin/activate` to create
 and activate a virtual environment.

flashloader/image-loader.py

@@ -1,6 +1,8 @@
 #!/usr/bin/env python3
+from typing import List, Tuple
 from spacepackets.ecss.defs import PusService
 from spacepackets.ecss.tm import PusTm
+from tmtccmd.com import ComInterface
 import toml
 import struct
 import logging
@@ -21,20 +23,27 @@ from elftools.elf.elffile import ELFFile
 
 
 BAUD_RATE = 115200
+
 BOOTLOADER_START_ADDR = 0x0
 BOOTLOADER_END_ADDR = 0x4000
-BOOTLOADER_CRC_ADDR = 0x3FFC
+BOOTLOADER_CRC_ADDR = BOOTLOADER_END_ADDR - 4
+BOOTLOADER_MAX_SIZE = BOOTLOADER_END_ADDR - BOOTLOADER_START_ADDR - 4
+
 APP_A_START_ADDR = 0x4000
 APP_A_END_ADDR = 0x22000
 # The actual size of the image which is relevant for CRC calculation.
-APP_A_SIZE_ADDR = 0x21FF8
-APP_A_CRC_ADDR = 0x21FFC
+APP_A_SIZE_ADDR = APP_A_END_ADDR - 8
+APP_A_CRC_ADDR = APP_A_END_ADDR - 4
+APP_A_MAX_SIZE = APP_A_END_ADDR - APP_A_START_ADDR - 8
+
 APP_B_START_ADDR = 0x22000
 APP_B_END_ADDR = 0x40000
 # The actual size of the image which is relevant for CRC calculation.
-APP_B_SIZE_ADDR = 0x3FFF8
-APP_B_CRC_ADDR = 0x3FFFC
-APP_IMG_SZ = 0x1E000
+APP_B_SIZE_ADDR = APP_B_END_ADDR - 8
+APP_B_CRC_ADDR = APP_B_END_ADDR - 4
+APP_B_MAX_SIZE = APP_A_END_ADDR - APP_A_START_ADDR - 8
+
+APP_IMG_SZ = (APP_B_END_ADDR - APP_A_START_ADDR) // 2
 
 CHUNK_SIZE = 896
 
@@ -52,6 +61,7 @@ class ActionId(enum.IntEnum):
 
 
 _LOGGER = logging.getLogger(__name__)
+SEQ_PROVIDER = SeqCountProvider(bit_width=14)
 
 
 @dataclasses.dataclass
@@ -62,7 +72,174 @@ class LoadableSegment:
     data: bytes
 
 
-SEQ_PROVIDER = SeqCountProvider(bit_width=14)
+class Target(enum.Enum):
+    BOOTLOADER = 0
+    APP_A = 1
+    APP_B = 2
+
+
+class ImageLoader:
+    def __init__(self, com_if: ComInterface, verificator: PusVerificator) -> None:
+        self.com_if = com_if
+        self.verificator = verificator
+
+    def handle_ping_cmd(self):
+        _LOGGER.info("Sending ping command")
+        ping_tc = PusTc(
+            apid=0x00,
+            service=PusService.S17_TEST,
+            subservice=1,
+            seq_count=SEQ_PROVIDER.get_and_increment(),
+            app_data=bytes(PING_PAYLOAD_SIZE),
+        )
+        self.verificator.add_tc(ping_tc)
+        self.com_if.send(bytes(ping_tc.pack()))
+
+        data_available = self.com_if.data_available(0.4)
+        if not data_available:
+            _LOGGER.warning("no ping reply received")
+        for reply in self.com_if.receive():
+            result = self.verificator.add_tm(
+                Service1Tm.from_tm(PusTm.unpack(reply, 0), UnpackParams(0))
+            )
+            if result is not None and result.completed:
+                _LOGGER.info("received ping completion reply")
+
+    def handle_corruption_cmd(self, target: Target):
+
+        if target == Target.BOOTLOADER:
+            _LOGGER.error("can not corrupt bootloader")
+        if target == Target.APP_A:
+            self.send_tc(
+                PusTc(
+                    apid=0,
+                    service=ACTION_SERVICE,
+                    subservice=ActionId.CORRUPT_APP_A,
+                ),
+            )
+        if target == Target.APP_B:
+            self.send_tc(
+                PusTc(
+                    apid=0,
+                    service=ACTION_SERVICE,
+                    subservice=ActionId.CORRUPT_APP_B,
+                ),
+            )
+
+    def handle_flash_cmd(self, target: Target, file_path: Path) -> int:
+        loadable_segments = []
+        _LOGGER.info("Parsing ELF file for loadable sections")
+        total_size = 0
+        loadable_segments, total_size = create_loadable_segments(target, file_path)
+        segments_info_str(target, loadable_segments, total_size, file_path)
+        result = self._perform_flashing_algorithm(loadable_segments)
+        if result != 0:
+            return result
+        self._crc_and_app_size_postprocessing(target, total_size, loadable_segments)
+        return 0
+
+    def _perform_flashing_algorithm(
+        self,
+        loadable_segments: List[LoadableSegment],
+    ) -> int:
+        # Perform the flashing algorithm.
+        for segment in loadable_segments:
+            segment_end = segment.offset + segment.size
+            current_addr = segment.offset
+            pos_in_segment = 0
+            while pos_in_segment < segment.size:
+                next_chunk_size = min(segment_end - current_addr, CHUNK_SIZE)
+                data = segment.data[pos_in_segment : pos_in_segment + next_chunk_size]
+                next_packet = pack_memory_write_command(current_addr, data)
+                _LOGGER.info(
+                    f"Sending memory write command for address {current_addr:#08x} and data with "
+                    f"length {len(data)}"
+                )
+                self.verificator.add_tc(next_packet)
+                self.com_if.send(bytes(next_packet.pack()))
+                current_addr += next_chunk_size
+                pos_in_segment += next_chunk_size
+                start_time = time.time()
+                while True:
+                    if time.time() - start_time > 1.0:
+                        _LOGGER.error("Timeout while waiting for reply")
+                        return -1
+                    data_available = self.com_if.data_available(0.1)
+                    done = False
+                    if not data_available:
+                        continue
+                    replies = self.com_if.receive()
+                    for reply in replies:
+                        tm = PusTm.unpack(reply, 0)
+                        if tm.service != 1:
+                            continue
+                        service_1_tm = Service1Tm.from_tm(tm, UnpackParams(0))
+                        check_result = self.verificator.add_tm(service_1_tm)
+                        # We could send after we have received the step reply, but that can
+                        # somehow lead to overrun errors. I think it's okay to do it like
+                        # this as long as the flash loader only uses polling..
+                        if (
+                            check_result is not None
+                            and check_result.status.completed == StatusField.SUCCESS
+                        ):
+                            done = True
+
+                        # This is an optimized variant, but I think the small delay is not an issue.
+                        """
+                        if (
+                            check_result is not None
+                            and check_result.status.step == StatusField.SUCCESS
+                            and len(check_result.status.step_list) == 1
+                        ):
+                            done = True
+                        """
+                    self.verificator.remove_completed_entries()
+                    if done:
+                        break
+        return 0
+
+    def _crc_and_app_size_postprocessing(
+        self,
+        target: Target,
+        total_size: int,
+        loadable_segments: List[LoadableSegment],
+    ):
+        if target == Target.BOOTLOADER:
+            _LOGGER.info("Blanking the bootloader checksum")
+            # Blank the checksum. For the bootloader, the bootloader will calculate the
+            # checksum itself on the initial run.
+            checksum_write_packet = pack_memory_write_command(
+                BOOTLOADER_CRC_ADDR, bytes([0x00, 0x00, 0x00, 0x00])
+            )
+            self.send_tc(checksum_write_packet)
+        else:
+            crc_addr = None
+            size_addr = None
+            if target == Target.APP_A:
+                crc_addr = APP_A_CRC_ADDR
+                size_addr = APP_A_SIZE_ADDR
+            elif target == Target.APP_B:
+                crc_addr = APP_B_CRC_ADDR
+                size_addr = APP_B_SIZE_ADDR
+            assert crc_addr is not None
+            assert size_addr is not None
+            _LOGGER.info(f"Writing app size {total_size} at address {size_addr:#08x}")
+            size_write_packet = pack_memory_write_command(
+                size_addr, struct.pack("!I", total_size)
+            )
+            self.com_if.send(bytes(size_write_packet.pack()))
+            time.sleep(0.2)
+            crc_calc = PredefinedCrc("crc-32")
+            for segment in loadable_segments:
+                crc_calc.update(segment.data)
+            checksum = crc_calc.digest()
+            _LOGGER.info(
+                f"Writing checksum 0x[{checksum.hex(sep=',')}] at address {crc_addr:#08x}"
+            )
+            self.send_tc(pack_memory_write_command(crc_addr, checksum))
+
+    def send_tc(self, tc: PusTc):
+        self.com_if.send(bytes(tc.pack()))
 
 
 def main() -> int:
@@ -102,74 +279,57 @@ def main() -> int:
     verificator = PusVerificator()
     com_if = SerialCobsComIF(serial_cfg)
     com_if.open()
+    target = None
+    if args.target == "bl":
+        target = Target.BOOTLOADER
+    elif args.target == "a":
+        target = Target.APP_A
+    elif args.target == "b":
+        target = Target.APP_B
+    image_loader = ImageLoader(com_if, verificator)
     file_path = None
+    result = -1
     if args.ping:
-        _LOGGER.info("Sending ping command")
-        ping_tc = PusTc(
-            apid=0x00,
-            service=PusService.S17_TEST,
-            subservice=1,
-            seq_count=SEQ_PROVIDER.get_and_increment(),
-            app_data=bytes(PING_PAYLOAD_SIZE),
-        )
-        verificator.add_tc(ping_tc)
-        com_if.send(ping_tc.pack())
-
-        data_available = com_if.data_available(0.4)
-        if not data_available:
-            _LOGGER.warning("no ping reply received")
-        for reply in com_if.receive():
-            result = verificator.add_tm(
-                Service1Tm.from_tm(PusTm.unpack(reply, 0), UnpackParams(0))
-            )
-            if result is not None and result.completed:
-                _LOGGER.info("received ping completion reply")
-        if not args.target:
+        image_loader.handle_ping_cmd()
+        com_if.close()
         return 0
-    if args.target:
+    if target:
         if not args.corrupt:
             if not args.path:
                 _LOGGER.error("App Path needs to be specified for the flash process")
-                return -1
             file_path = Path(args.path)
             if not file_path.exists():
                 _LOGGER.error("File does not exist")
-                return -1
     if args.corrupt:
-        if not args.target:
+        if not target:
             _LOGGER.error("target for corruption command required")
+            com_if.close()
             return -1
-        if args.target == "bl":
-            _LOGGER.error("can not corrupt bootloader")
-        if args.target == "a":
-            packet = PusTc(
-                apid=0,
-                service=ACTION_SERVICE,
-                subservice=ActionId.CORRUPT_APP_A,
-            )
-            com_if.send(packet.pack())
-        if args.target == "b":
-            packet = PusTc(
-                apid=0,
-                service=ACTION_SERVICE,
-                subservice=ActionId.CORRUPT_APP_B,
-            )
-            com_if.send(packet.pack())
+        image_loader.handle_corruption_cmd(target)
     else:
         assert file_path is not None
+        assert target is not None
+        result = image_loader.handle_flash_cmd(target, file_path)
+
+    com_if.close()
+    return result
+
+
+def create_loadable_segments(
+    target: Target, file_path: Path
+) -> Tuple[List[LoadableSegment], int]:
     loadable_segments = []
-        _LOGGER.info("Parsing ELF file for loadable sections")
     total_size = 0
     with open(file_path, "rb") as app_file:
         elf_file = ELFFile(app_file)
 
-            for (idx, segment) in enumerate(elf_file.iter_segments("PT_LOAD")):
+        for idx, segment in enumerate(elf_file.iter_segments("PT_LOAD")):
             if segment.header.p_filesz == 0:
                 continue
             # Basic validity checks of the base addresses.
             if idx == 0:
                 if (
-                        args.target == "bl"
+                    target == Target.BOOTLOADER
                     and segment.header.p_paddr != BOOTLOADER_START_ADDR
                 ):
                     raise ValueError(
@@ -177,7 +337,7 @@ def main() -> int:
                         f"bootloader, expected {BOOTLOADER_START_ADDR}"
                     )
                 if (
-                        args.target == "a"
+                    target == Target.APP_A
                     and segment.header.p_paddr != APP_A_START_ADDR
                 ):
                     raise ValueError(
@@ -185,7 +345,7 @@ def main() -> int:
                         f"App A, expected {APP_A_START_ADDR}"
                     )
                 if (
-                        args.target == "b"
+                    target == Target.APP_B
                     and segment.header.p_paddr != APP_B_START_ADDR
                 ):
                     raise ValueError(
@@ -214,101 +374,39 @@ def main() -> int:
                 )
             )
             total_size += segment.header.p_filesz
-            context_str = None
-            if args.target == "bl":
-                context_str = "Bootloader"
-            elif args.target == "a":
-                context_str = "App Slot A"
-            elif args.target == "b":
-                context_str = "App Slot B"
-            _LOGGER.info(
-                f"Flashing {context_str} with image {file_path} (size {total_size})"
+    return loadable_segments, total_size
+
+
+def segments_info_str(
+    target: Target,
+    loadable_segments: List[LoadableSegment],
+    total_size: int,
+    file_path: Path,
+):
+    # Set context string and perform basic sanity checks.
+    if target == Target.BOOTLOADER:
+        if total_size > BOOTLOADER_MAX_SIZE:
+            _LOGGER.error(
+                f"provided bootloader app larger than allowed {total_size} bytes"
             )
+            return -1
+        context_str = "Bootloader"
+    elif target == Target.APP_A:
+        if total_size > APP_A_MAX_SIZE:
+            _LOGGER.error(f"provided App A larger than allowed {total_size} bytes")
+            return -1
+        context_str = "App Slot A"
+    elif target == Target.APP_B:
+        if total_size > APP_B_MAX_SIZE:
+            _LOGGER.error(f"provided App B larger than allowed {total_size} bytes")
+            return -1
+        context_str = "App Slot B"
+    _LOGGER.info(f"Flashing {context_str} with image {file_path} (size {total_size})")
     for idx, segment in enumerate(loadable_segments):
         _LOGGER.info(
-                    f"Loadable section {idx} {segment.name} with offset {segment.offset:#08x} and size {segment.size}"
+            f"Loadable section {idx} {segment.name} with offset {segment.offset:#08x} and "
+            f"size {segment.size}"
         )
-            for segment in loadable_segments:
-                segment_end = segment.offset + segment.size
-                current_addr = segment.offset
-                pos_in_segment = 0
-                while pos_in_segment < segment.size:
-                    next_chunk_size = min(segment_end - current_addr, CHUNK_SIZE)
-                    data = segment.data[
-                        pos_in_segment : pos_in_segment + next_chunk_size
-                    ]
-                    next_packet = pack_memory_write_command(current_addr, data)
-                    _LOGGER.info(
-                        f"Sending memory write command for address {current_addr:#08x} and data with "
-                        f"length {len(data)}"
-                    )
-                    verificator.add_tc(next_packet)
-                    com_if.send(next_packet.pack())
-                    current_addr += next_chunk_size
-                    pos_in_segment += next_chunk_size
-                    while True:
-                        data_available = com_if.data_available(0.1)
-                        done = False
-                        if not data_available:
-                            continue
-                        replies = com_if.receive()
-                        for reply in replies:
-                            tm = PusTm.unpack(reply, 0)
-                            if tm.service != 1:
-                                continue
-                            service_1_tm = Service1Tm.from_tm(tm, UnpackParams(0))
-                            check_result = verificator.add_tm(service_1_tm)
-                            # We could send after we have received the step reply, but that can
-                            # somehow lead to overrun errors. I think it's okay to do it like
-                            # this as long as the flash loader only uses polling..
-                            if (
-                                check_result is not None
-                                and check_result.status.completed == StatusField.SUCCESS
-                            ):
-                                done = True
-                                # Still keep a small delay
-                                # time.sleep(0.05)
-                        verificator.remove_completed_entries()
-                        if done:
-                            break
-            if args.target == "bl":
-                _LOGGER.info("Blanking the bootloader checksum")
-                # Blank the checksum. For the bootloader, the bootloader will calculate the
-                # checksum itself on the initial run.
-                checksum_write_packet = pack_memory_write_command(
-                    BOOTLOADER_CRC_ADDR, bytes([0x00, 0x00, 0x00, 0x00])
-                )
-                com_if.send(checksum_write_packet.pack())
-            else:
-                crc_addr = None
-                size_addr = None
-                if args.target == "a":
-                    crc_addr = APP_A_CRC_ADDR
-                    size_addr = APP_A_SIZE_ADDR
-                elif args.target == "b":
-                    crc_addr = APP_B_CRC_ADDR
-                    size_addr = APP_B_SIZE_ADDR
-                assert crc_addr is not None
-                assert size_addr is not None
-                _LOGGER.info(
-                    f"Writing app size {total_size} at address {size_addr:#08x}"
-                )
-                size_write_packet = pack_memory_write_command(
-                    size_addr, struct.pack("!I", total_size)
-                )
-                com_if.send(size_write_packet.pack())
-                time.sleep(0.2)
-                crc_calc = PredefinedCrc("crc-32")
-                for segment in loadable_segments:
-                    crc_calc.update(segment.data)
-                checksum = crc_calc.digest()
-                _LOGGER.info(
-                    f"Writing checksum 0x[{checksum.hex(sep=',')}] at address {crc_addr:#08x}"
-                )
-                checksum_write_packet = pack_memory_write_command(crc_addr, checksum)
-                com_if.send(checksum_write_packet.pack())
-    com_if.close()
-    return 0
 
 
 def pack_memory_write_command(addr: int, data: bytes) -> PusTc:
@@ -324,7 +422,7 @@ def pack_memory_write_command(addr: int, data: bytes) -> PusTc:
         service=MEMORY_SERVICE,
         subservice=RAW_MEMORY_WRITE_SUBSERVICE,
         seq_count=SEQ_PROVIDER.get_and_increment(),
-        app_data=app_data,
+        app_data=bytes(app_data),
     )
 
 

flashloader/slot-a-blinky/Cargo.toml

@@ -7,11 +7,11 @@ edition = "2021"
 
 [dependencies]
 cortex-m-rt = "0.7"
-va416xx-hal = { path = "../../va416xx-hal" }
 panic-rtt-target = { version = "0.1.3" }
 rtt-target = { version = "0.5" }
 cortex-m = { version = "0.7", features = ["critical-section-single-core"] }
 embedded-hal = "1"
+va416xx-hal = { path = "../../va416xx-hal", features = ["va41630"] }
 
 [profile.dev]
 codegen-units = 1

flashloader/slot-b-blinky/Cargo.toml

@@ -7,11 +7,11 @@ edition = "2021"
 
 [dependencies]
 cortex-m-rt = "0.7"
-va416xx-hal = { path = "../../va416xx-hal" }
 panic-rtt-target = { version = "0.1.3" }
 rtt-target = { version = "0.5" }
 cortex-m = { version = "0.7", features = ["critical-section-single-core"] }
 embedded-hal = "1"
+va416xx-hal = { path = "../../va416xx-hal", features = ["va41630"] }
 
 [profile.dev]
 codegen-units = 1

flashloader/src/main.rs

@@ -109,6 +109,7 @@ mod app {
         tc::PusTcReader, tm::PusTmCreator, EcssEnumU8, PusPacket, WritablePusPacket,
     };
     use va416xx_hal::irq_router::enable_and_init_irq_router;
+    use va416xx_hal::uart::IrqContextTimeoutOrMaxSize;
     use va416xx_hal::{
         clock::ClkgenExt,
         edac,
@@ -132,6 +133,7 @@ mod app {
     struct Local {
         uart_rx: uart::RxWithIrq<pac::Uart0>,
         uart_tx: uart::Tx<pac::Uart0>,
+        rx_context: IrqContextTimeoutOrMaxSize,
         rom_spi: Option<pac::Spi3>,
         // We handle all TM in one task.
         tm_cons: DataConsumer<BUF_RB_SIZE_TM, SIZES_RB_SIZE_TM>,
@@ -167,9 +169,9 @@ mod app {
         enable_and_init_irq_router(&mut cx.device.sysconfig, &cx.device.irq_router);
         setup_edac(&mut cx.device.sysconfig);
 
-        let gpiob = PinsG::new(&mut cx.device.sysconfig, cx.device.portg);
-        let tx = gpiob.pg0.into_funsel_1();
-        let rx = gpiob.pg1.into_funsel_1();
+        let gpiog = PinsG::new(&mut cx.device.sysconfig, cx.device.portg);
+        let tx = gpiog.pg0.into_funsel_1();
+        let rx = gpiog.pg1.into_funsel_1();
 
         let uart0 = Uart::new(
             cx.device.uart0,
@@ -178,7 +180,7 @@ mod app {
             &mut cx.device.sysconfig,
             &clocks,
         );
-        let (tx, mut rx, _) = uart0.split_with_irq();
+        let (tx, rx) = uart0.split();
 
         let verif_reporter = VerificationReportCreator::new(0).unwrap();
 
@@ -191,7 +193,9 @@ mod app {
         Mono::start(cx.core.SYST, clocks.sysclk().raw());
         CLOCKS.set(clocks).unwrap();
 
-        rx.read_fixed_len_using_irq(MAX_TC_FRAME_SIZE, true)
+        let mut rx = rx.to_rx_with_irq();
+        let mut rx_context = IrqContextTimeoutOrMaxSize::new(MAX_TC_FRAME_SIZE);
+        rx.read_fixed_len_or_timeout_based_using_irq(&mut rx_context)
             .expect("initiating UART RX failed");
         pus_tc_handler::spawn().unwrap();
         pus_tm_tx_handler::spawn().unwrap();
@@ -205,6 +209,7 @@ mod app {
             Local {
                 uart_rx: rx,
                 uart_tx: tx,
+                rx_context,
                 rom_spi: Some(cx.device.spi3),
                 tm_cons: DataConsumer {
                     buf_cons: buf_cons_tm,
@@ -231,20 +236,26 @@ mod app {
         }
     }
 
+    // This is the interrupt handler to read all bytes received on the UART0.
     #[task(
         binds = UART0_RX,
         local = [
             cnt: u32 = 0,
             rx_buf: [u8; MAX_TC_FRAME_SIZE] = [0; MAX_TC_FRAME_SIZE],
+            rx_context,
             uart_rx,
             tc_prod
         ],
     )]
     fn uart_rx_irq(cx: uart_rx_irq::Context) {
-        match cx.local.uart_rx.irq_handler(cx.local.rx_buf) {
+        match cx
+            .local
+            .uart_rx
+            .irq_handler_max_size_or_timeout_based(cx.local.rx_context, cx.local.rx_buf)
+        {
             Ok(result) => {
                 if RX_DEBUGGING {
-                    log::debug!("RX Info: {:?}", cx.local.uart_rx.irq_info());
+                    log::debug!("RX Info: {:?}", cx.local.rx_context);
                     log::debug!("RX Result: {:?}", result);
                 }
                 if result.complete() {
@@ -279,11 +290,11 @@ mod app {
                     // Initiate next transfer.
                     cx.local
                         .uart_rx
-                        .read_fixed_len_using_irq(MAX_TC_FRAME_SIZE, true)
+                        .read_fixed_len_or_timeout_based_using_irq(cx.local.rx_context)
                         .expect("read operation failed");
                 }
-                if result.error() {
-                    log::warn!("UART error: {:?}", result.error());
+                if result.has_errors() {
+                    log::warn!("UART error: {:?}", result.errors.unwrap());
                 }
             }
             Err(e) => {
@@ -438,7 +449,12 @@ mod app {
                     return;
                 }
                 let data = &app_data[10..10 + data_len as usize];
-                log::info!("writing {} bytes at offset {} to NVM", data_len, offset);
+                log::info!(
+                    target: "TC Handler",
+                    "writing {} bytes at offset {} to NVM",
+                    data_len,
+                    offset
+                );
                 // Safety: We only use this for NVM handling and we only do NVM
                 // handling here.
                 let mut sys_cfg = unsafe { pac::Sysconfig::steal() };
@@ -455,7 +471,9 @@ mod app {
                     .completion_success(cx.local.src_data_buf, started_token, 0, 0, &[])
                     .expect("completion success failed");
                 write_and_send(&tm);
-                log::info!("NVM operation done");
+                log::info!(
+                    target: "TC Handler",
+                    "NVM operation done");
             }
         }
     }

va416xx-hal/CHANGELOG.md

@@ -8,6 +8,21 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 # [unreleased]
 
+## Changed
+
+- Improve and fix SPI abstractions. Add new low level interface. The primary SPI constructor now
+  only expects a configuration structure and the transfer configuration needs to be applied in a
+  separate step.
+- Added an additional way to read the UART RX with IRQs. The module documentation provides
+  more information.
+- Made the UART with IRQ API more flexible for future additions.
+
+## Fixed
+
+- Fixes for SPI peripheral: Flush implementation was incorrect and should now flush properly.
+- Fixes for SPI example
+- Fixes for RTIC example
+
 # [v0.2.0] 2024-09-18
 
 - Documentation improvements

va416xx-hal/src/gpio/reg.rs

@@ -113,14 +113,6 @@ pub(super) unsafe trait RegisterInterface {
     /// this type.
     fn id(&self) -> DynPinId;
 
-    const PORTA: *const PortRegisterBlock = Porta::ptr();
-    const PORTB: *const PortRegisterBlock = Portb::ptr();
-    const PORTC: *const PortRegisterBlock = Portc::ptr();
-    const PORTD: *const PortRegisterBlock = Portd::ptr();
-    const PORTE: *const PortRegisterBlock = Porte::ptr();
-    const PORTF: *const PortRegisterBlock = Portf::ptr();
-    const PORTG: *const PortRegisterBlock = Portg::ptr();
-
     /// Change the pin mode
     #[inline]
     fn change_mode(&mut self, mode: DynPinMode) {
@@ -155,13 +147,13 @@ pub(super) unsafe trait RegisterInterface {
     #[inline]
     fn port_reg(&self) -> &PortRegisterBlock {
         match self.id().group {
-            DynGroup::A => unsafe { &(*Self::PORTA) },
-            DynGroup::B => unsafe { &(*Self::PORTB) },
-            DynGroup::C => unsafe { &(*Self::PORTC) },
-            DynGroup::D => unsafe { &(*Self::PORTD) },
-            DynGroup::E => unsafe { &(*Self::PORTE) },
-            DynGroup::F => unsafe { &(*Self::PORTF) },
-            DynGroup::G => unsafe { &(*Self::PORTG) },
+            DynGroup::A => unsafe { &(*Porta::ptr()) },
+            DynGroup::B => unsafe { &(*Portb::ptr()) },
+            DynGroup::C => unsafe { &(*Portc::ptr()) },
+            DynGroup::D => unsafe { &(*Portd::ptr()) },
+            DynGroup::E => unsafe { &(*Porte::ptr()) },
+            DynGroup::F => unsafe { &(*Portf::ptr()) },
+            DynGroup::G => unsafe { &(*Portg::ptr()) },
         }
     }
 

va416xx-hal/src/pwm.rs

@@ -9,8 +9,10 @@ use core::convert::Infallible;
 use core::marker::PhantomData;
 
 use crate::pac;
+use crate::time::Hertz;
+pub use crate::timer::ValidTim;
+use crate::timer::{TimAndPinRegister, TimDynRegister, TimPin, TimRegInterface, ValidTimAndPin};
 use crate::{clock::Clocks, gpio::DynPinId};
-pub use crate::{gpio::PinId, time::Hertz, timer::*};
 
 const DUTY_MAX: u16 = u16::MAX;
 

va416xx-hal/src/uart.rs

@@ -1,9 +1,15 @@
 //! # API for the UART peripheral
 //!
+//! The core of this API are the [Uart], [UartBase], [Rx] and [Tx] structures.
+//! The RX structure also has a dedicated [RxWithIrq] variant which allows reading the receiver
+//! using interrupts.
+//!
 //! ## Examples
 //!
 //! - [UART simple example](https://egit.irs.uni-stuttgart.de/rust/va416xx-rs/src/branch/main/examples/simple/examples/uart.rs)
+//! - [UART echo with IRQ and Embassy](https://egit.irs.uni-stuttgart.de/rust/va416xx-rs/src/branch/main/examples/embassy/src/bin/uart-echo-with-irq.rs)
 //! - [Flashloader app using UART with IRQs](https://egit.irs.uni-stuttgart.de/rust/va416xx-rs/src/branch/main/flashloader)
+use core::convert::Infallible;
 use core::ops::Deref;
 
 use embedded_hal_nb::serial::Read;
@@ -64,15 +70,28 @@ impl RxPin<Uart2> for Pin<PF9, AltFunc1> {}
 // Regular Definitions
 //==================================================================================================
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub struct TransferPendingError;
+
+#[derive(Debug, PartialEq, Eq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub enum RxError {
+    Overrun,
+    Framing,
+    Parity,
+}
+#[derive(Debug, PartialEq, Eq)]
 #[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum Error {
-    Overrun,
-    FramingError,
-    ParityError,
+    Rx(RxError),
     BreakCondition,
-    TransferPending,
-    BufferTooShort,
+}
+
+impl From<RxError> for Error {
+    fn from(value: RxError) -> Self {
+        Self::Rx(value)
+    }
 }
 
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
@@ -198,54 +217,75 @@ impl From<Hertz> for Config {
 // IRQ Definitions
 //==================================================================================================
 
-#[derive(Debug)]
-pub struct IrqInfo {
-    rx_len: usize,
+#[derive(Debug, Copy, Clone)]
+pub struct IrqContextTimeoutOrMaxSize {
     rx_idx: usize,
     mode: IrqReceptionMode,
+    pub max_len: usize,
+}
+
+impl IrqContextTimeoutOrMaxSize {
+    pub fn new(max_len: usize) -> Self {
+        IrqContextTimeoutOrMaxSize {
+            rx_idx: 0,
+            max_len,
+            mode: IrqReceptionMode::Idle,
+        }
+    }
+}
+
+impl IrqContextTimeoutOrMaxSize {
+    pub fn reset(&mut self) {
+        self.rx_idx = 0;
+        self.mode = IrqReceptionMode::Idle;
+    }
 }
 
 /// This struct is used to return the default IRQ handler result to the user
 #[derive(Debug, Default)]
 pub struct IrqResult {
+    pub bytes_read: usize,
+    pub errors: Option<IrqUartError>,
+}
+
+/// This struct is used to return the default IRQ handler result to the user
+#[derive(Debug, Default)]
+pub struct IrqResultMaxSizeOrTimeout {
     complete: bool,
     timeout: bool,
-    pub errors: IrqUartError,
+    pub errors: Option<IrqUartError>,
     pub bytes_read: usize,
 }
 
-impl IrqResult {
+impl IrqResultMaxSizeOrTimeout {
     pub fn new() -> Self {
-        IrqResult {
+        IrqResultMaxSizeOrTimeout {
             complete: false,
             timeout: false,
-            errors: IrqUartError::default(),
+            errors: None,
             bytes_read: 0,
         }
     }
 }
-impl IrqResult {
+impl IrqResultMaxSizeOrTimeout {
     #[inline]
-    pub fn error(&self) -> bool {
-        if self.errors.overflow || self.errors.parity || self.errors.framing {
-            return true;
-        }
-        false
+    pub fn has_errors(&self) -> bool {
+        self.errors.is_some()
     }
 
     #[inline]
     pub fn overflow_error(&self) -> bool {
-        self.errors.overflow
+        self.errors.map_or(false, |e| e.overflow)
     }
 
     #[inline]
     pub fn framing_error(&self) -> bool {
-        self.errors.framing
+        self.errors.map_or(false, |e| e.framing)
     }
 
     #[inline]
     pub fn parity_error(&self) -> bool {
-        self.errors.parity
+        self.errors.map_or(false, |e| e.parity)
     }
 
     #[inline]
@@ -259,52 +299,16 @@ impl IrqResult {
     }
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Copy, Clone)]
 enum IrqReceptionMode {
     Idle,
     Pending,
 }
 
 //==================================================================================================
-// UART implementation
+// UART peripheral wrapper
 //==================================================================================================
 
-/// Type erased variant of a UART. Can be created with the [Uart::downgrade] function.
-pub struct UartBase<Uart> {
-    uart: Uart,
-    tx: Tx<Uart>,
-    rx: Rx<Uart>,
-}
-/// Serial abstraction. Entry point to create a new UART
-pub struct Uart<UartInstance, Pins> {
-    inner: UartBase<UartInstance>,
-    pins: Pins,
-}
-
-/// Serial receiver
-pub struct Rx<Uart>(Uart);
-
-// Serial receiver, using interrupts to offload reading to the hardware.
-pub struct RxWithIrq<Uart> {
-    inner: Rx<Uart>,
-    irq_info: IrqInfo,
-}
-
-/// Serial transmitter
-pub struct Tx<Uart>(Uart);
-
-impl<Uart: Instance> Rx<Uart> {
-    fn new(uart: Uart) -> Self {
-        Self(uart)
-    }
-}
-
-impl<Uart> Tx<Uart> {
-    fn new(uart: Uart) -> Self {
-        Self(uart)
-    }
-}
-
 pub trait Instance: Deref<Target = uart_base::RegisterBlock> {
     const IDX: u8;
     const PERIPH_SEL: PeripheralSelect;
@@ -362,6 +366,17 @@ impl Instance for Uart2 {
     }
 }
 
+//==================================================================================================
+// UART implementation
+//==================================================================================================
+
+/// Type erased variant of a UART. Can be created with the [Uart::downgrade] function.
+pub struct UartBase<Uart> {
+    uart: Uart,
+    tx: Tx<Uart>,
+    rx: Rx<Uart>,
+}
+
 impl<Uart: Instance> UartBase<Uart> {
     fn init(self, config: Config, clocks: &Clocks) -> Self {
         if Uart::IDX == 2 {
@@ -495,6 +510,12 @@ impl<Uart: Instance> UartBase<Uart> {
     }
 }
 
+/// Serial abstraction. Entry point to create a new UART
+pub struct Uart<UartInstance, Pins> {
+    inner: UartBase<UartInstance>,
+    pins: Pins,
+}
+
 impl<TxPinInst: TxPin<UartInstance>, RxPinInst: RxPin<UartInstance>, UartInstance: Instance>
     Uart<UartInstance, (TxPinInst, RxPinInst)>
 {
@@ -551,33 +572,6 @@ impl<TxPinInst: TxPin<UartInstance>, RxPinInst: RxPin<UartInstance>, UartInstanc
         self
     }
 
-    /// If the IRQ capabilities of the peripheral are used, the UART needs to be converted
-    /// with this function. Currently, IRQ abstractions are only implemented for the RX part
-    /// of the UART, so this function will release a TX and RX handle as well as the pin
-    /// instances.
-    pub fn split_with_irq(
-        self,
-    ) -> (
-        Tx<UartInstance>,
-        RxWithIrq<UartInstance>,
-        (TxPinInst, RxPinInst),
-    ) {
-        let (inner, pins) = self.downgrade_internal();
-        let (tx, rx) = inner.split();
-        (
-            tx,
-            RxWithIrq {
-                inner: rx,
-                irq_info: IrqInfo {
-                    rx_len: 0,
-                    rx_idx: 0,
-                    mode: IrqReceptionMode::Idle,
-                },
-            },
-            pins,
-        )
-    }
-
     delegate::delegate! {
         to self.inner {
             #[inline]
@@ -604,15 +598,6 @@ impl<TxPinInst: TxPin<UartInstance>, RxPinInst: RxPin<UartInstance>, UartInstanc
         }
     }
 
-    fn downgrade_internal(self) -> (UartBase<UartInstance>, (TxPinInst, RxPinInst)) {
-        let base = UartBase {
-            uart: self.inner.uart,
-            tx: self.inner.tx,
-            rx: self.inner.rx,
-        };
-        (base, self.pins)
-    }
-
     pub fn downgrade(self) -> UartBase<UartInstance> {
         UartBase {
             uart: self.inner.uart,
@@ -626,6 +611,17 @@ impl<TxPinInst: TxPin<UartInstance>, RxPinInst: RxPin<UartInstance>, UartInstanc
     }
 }
 
+/// Serial receiver.
+///
+/// Can be created by using the [Uart::split] or [UartBase::split] API.
+pub struct Rx<Uart>(Uart);
+
+impl<Uart: Instance> Rx<Uart> {
+    fn new(uart: Uart) -> Self {
+        Self(uart)
+    }
+}
+
 impl<Uart: Instance> Rx<Uart> {
     /// Direct access to the peripheral structure.
     ///
@@ -651,11 +647,53 @@ impl<Uart: Instance> Rx<Uart> {
         self.0.enable().modify(|_, w| w.rxenable().clear_bit());
     }
 
+    /// Low level function to read a word from the UART FIFO.
+    ///
+    /// Uses the [nb] API to allow usage in blocking and non-blocking contexts.
+    ///
+    /// Please note that you might have to mask the returned value with 0xff to retrieve the actual
+    /// value if you use the manual parity mode. See chapter 11.4.1 for more information.
+    #[inline(always)]
+    pub fn read_fifo(&self) -> nb::Result<u32, Infallible> {
+        if self.0.rxstatus().read().rdavl().bit_is_clear() {
+            return Err(nb::Error::WouldBlock);
+        }
+        Ok(self.read_fifo_unchecked())
+    }
+
+    /// Low level function to read a word from from the UART FIFO.
+    ///
+    /// This does not necesarily mean there is a word in the FIFO available.
+    /// Use the [Self::read_fifo] function to read a word from the FIFO reliably using the [nb]
+    /// API.
+    ///
+    /// Please note that you might have to mask the returned value with 0xff to retrieve the actual
+    /// value if you use the manual parity mode. See chapter 11.4.1 for more information.
+    #[inline(always)]
+    pub fn read_fifo_unchecked(&self) -> u32 {
+        self.0.data().read().bits()
+    }
+
+    pub fn to_rx_with_irq(self) -> RxWithIrq<Uart> {
+        RxWithIrq(self)
+    }
+
     pub fn release(self) -> Uart {
         self.0
     }
 }
 
+/// Serial transmitter
+///
+/// Can be created by using the [Uart::split] or [UartBase::split] API.
+pub struct Tx<Uart>(Uart);
+
+impl<Uart> Tx<Uart> {
+    fn new(uart: Uart) -> Self {
+        Self(uart)
+    }
+}
+
 impl<Uart: Instance> Tx<Uart> {
     /// Direct access to the peripheral structure.
     ///
@@ -680,9 +718,35 @@ impl<Uart: Instance> Tx<Uart> {
     pub fn disable(&mut self) {
         self.0.enable().modify(|_, w| w.txenable().clear_bit());
     }
+
+    /// Low level function to write a word to the UART FIFO.
+    ///
+    /// Uses the [nb] API to allow usage in blocking and non-blocking contexts.
+    ///
+    /// Please note that you might have to mask the returned value with 0xff to retrieve the actual
+    /// value if you use the manual parity mode. See chapter 11.4.1 for more information.
+    #[inline(always)]
+    pub fn write_fifo(&self, data: u32) -> nb::Result<(), Infallible> {
+        if self.0.txstatus().read().wrrdy().bit_is_clear() {
+            return Err(nb::Error::WouldBlock);
+        }
+        self.write_fifo_unchecked(data);
+        Ok(())
+    }
+
+    /// Low level function to write a word to the UART FIFO.
+    ///
+    /// This does not necesarily mean that the FIFO can process another word because it might be
+    /// full.
+    /// Use the [Self::read_fifo] function to write a word to the FIFO reliably using the [nb]
+    /// API.
+    #[inline(always)]
+    pub fn write_fifo_unchecked(&self, data: u32) {
+        self.0.data().write(|w| unsafe { w.bits(data) });
+    }
 }
 
-#[derive(Default, Debug)]
+#[derive(Default, Debug, Copy, Clone)]
 pub struct IrqUartError {
     overflow: bool,
     framing: bool,
@@ -691,46 +755,97 @@ pub struct IrqUartError {
 }
 
 impl IrqUartError {
+    #[inline(always)]
+    pub fn overflow(&self) -> bool {
+        self.overflow
+    }
+
+    #[inline(always)]
+    pub fn framing(&self) -> bool {
+        self.framing
+    }
+
+    #[inline(always)]
+    pub fn parity(&self) -> bool {
+        self.parity
+    }
+
+    #[inline(always)]
+    pub fn other(&self) -> bool {
+        self.other
+    }
+}
+
+impl IrqUartError {
+    #[inline(always)]
     pub fn error(&self) -> bool {
         self.overflow || self.framing || self.parity
     }
 }
 
-#[derive(Debug)]
-pub enum IrqError {
-    BufferTooShort { found: usize, expected: usize },
-    Uart(IrqUartError),
+#[derive(Debug, PartialEq, Eq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
+pub struct BufferTooShortError {
+    found: usize,
+    expected: usize,
 }
 
+/// Serial receiver, using interrupts to offload reading to the hardware.
+///
+/// You can use [Rx::to_rx_with_irq] to convert a normal [Rx] structure into this structure.
+/// This structure provides two distinct ways to read the UART RX using interrupts. It should
+/// be noted that the interrupt service routine (ISR) still has to be provided by the user. However,
+/// this structure provides API calls which can be used inside the ISRs to simplify the reading
+/// of the UART.
+///
+///  1. The first way simply empties the FIFO on an interrupt into a user provided buffer. You
+///     can simply use [Self::start] to prepare the peripheral and then call the
+///     [Self::irq_handler] in the interrupt service routine.
+///  2. The second way reads packets bounded by a maximum size or a baudtick based timeout. You
+///     can use [Self::read_fixed_len_or_timeout_based_using_irq] to prepare the peripheral and
+///     then call the [Self::irq_handler_max_size_or_timeout_based] in the interrupt service
+///     routine. You have to call [Self::read_fixed_len_or_timeout_based_using_irq] in the ISR to
+///     start reading the next packet.
+pub struct RxWithIrq<Uart>(Rx<Uart>);
+
 impl<Uart: Instance> RxWithIrq<Uart> {
-    /// This initializes a non-blocking read transfer using the IRQ capabilities of the UART
-    /// peripheral.
-    ///
-    /// The only required information is the maximum length for variable sized reception
-    /// or the expected length for fixed length reception. If variable sized packets are expected,
-    /// the timeout functionality of the IRQ should be enabled as well. After calling this function,
-    /// the [`irq_handler`](Self::irq_handler) function should be called in the user interrupt
-    /// handler to read the received packets and reinitiate another transfer if desired.
-    pub fn read_fixed_len_using_irq(
-        &mut self,
-        max_len: usize,
-        enb_timeout_irq: bool,
-    ) -> Result<(), Error> {
-        if self.irq_info.mode != IrqReceptionMode::Idle {
-            return Err(Error::TransferPending);
-        }
-        self.irq_info.mode = IrqReceptionMode::Pending;
-        self.irq_info.rx_idx = 0;
-        self.irq_info.rx_len = max_len;
-        self.inner.enable();
-        self.enable_rx_irq_sources(enb_timeout_irq);
+    /// This function should be called once at initialization time if the regular
+    /// [Self::irq_handler] is used to read the UART receiver to enable and start the receiver.
+    pub fn start(&mut self) {
+        self.0.enable();
+        self.enable_rx_irq_sources(true);
         unsafe { enable_interrupt(Uart::IRQ_RX) };
+    }
+
+    #[inline(always)]
+    pub fn uart(&self) -> &Uart {
+        &self.0 .0
+    }
+
+    /// This function is used together with the [Self::irq_handler_max_size_or_timeout_based]
+    /// function to read packets with a maximum size or variable sized packets by using the
+    /// receive timeout of the hardware.
+    ///
+    /// This function should be called once at initialization to initiate the context state
+    /// and to [Self::start] the receiver. After that, it should be called after each
+    /// completed [Self::irq_handler_max_size_or_timeout_based] call to restart the reception
+    /// of a packet.
+    pub fn read_fixed_len_or_timeout_based_using_irq(
+        &mut self,
+        context: &mut IrqContextTimeoutOrMaxSize,
+    ) -> Result<(), TransferPendingError> {
+        if context.mode != IrqReceptionMode::Idle {
+            return Err(TransferPendingError);
+        }
+        context.mode = IrqReceptionMode::Pending;
+        context.rx_idx = 0;
+        self.start();
         Ok(())
     }
 
     #[inline]
     fn enable_rx_irq_sources(&mut self, timeout: bool) {
-        self.inner.0.irq_enb().modify(|_, w| {
+        self.uart().irq_enb().modify(|_, w| {
             if timeout {
                 w.irq_rx_to().set_bit();
             }
@@ -741,7 +856,7 @@ impl<Uart: Instance> RxWithIrq<Uart> {
 
     #[inline]
     fn disable_rx_irq_sources(&mut self) {
-        self.inner.0.irq_enb().modify(|_, w| {
+        self.uart().irq_enb().modify(|_, w| {
             w.irq_rx_to().clear_bit();
             w.irq_rx_status().clear_bit();
             w.irq_rx().clear_bit()
@@ -750,30 +865,89 @@ impl<Uart: Instance> RxWithIrq<Uart> {
 
     pub fn cancel_transfer(&mut self) {
         self.disable_rx_irq_sources();
-        self.inner.clear_fifo();
-        self.irq_info.rx_idx = 0;
-        self.irq_info.rx_len = 0;
+        self.0.clear_fifo();
     }
 
-    pub fn uart(&self) -> &Uart {
-        &self.inner.0
+    /// This function should be called in the user provided UART interrupt handler.
+    ///
+    /// It simply empties any bytes in the FIFO into the user provided buffer and returns the
+    /// result of the operation.
+    ///
+    /// This function will not disable the RX interrupts, so you don't need to call any other
+    /// API after calling this function to continue emptying the FIFO. RX errors are handled
+    /// as partial errors and are returned as part of the [IrqResult].
+    pub fn irq_handler(&mut self, buf: &mut [u8; 16]) -> IrqResult {
+        let mut result = IrqResult::default();
+
+        let irq_end = self.uart().irq_end().read();
+        let enb_status = self.uart().enable().read();
+        let rx_enabled = enb_status.rxenable().bit_is_set();
+
+        // Half-Full interrupt. We have a guaranteed amount of data we can read.
+        if irq_end.irq_rx().bit_is_set() {
+            let available_bytes = self.uart().rxfifoirqtrg().read().bits() as usize;
+
+            // If this interrupt bit is set, the trigger level is available at the very least.
+            // Read everything as fast as possible
+            for _ in 0..available_bytes {
+                buf[result.bytes_read] = (self.uart().data().read().bits() & 0xff) as u8;
+                result.bytes_read += 1;
+            }
         }
 
-    /// Default IRQ handler which can be used to read the packets arriving on the UART peripheral.
+        // Timeout, empty the FIFO completely.
+        if irq_end.irq_rx_to().bit_is_set() {
+            loop {
+                // While there is data in the FIFO, write it into the reception buffer
+                let read_result = self.0.read();
+                if let Some(byte) = self.read_handler(&mut result.errors, &read_result) {
+                    buf[result.bytes_read] = byte;
+                    result.bytes_read += 1;
+                } else {
+                    break;
+                }
+            }
+        }
+
+        // RX transfer not complete, check for RX errors
+        if rx_enabled {
+            self.check_for_errors(&mut result.errors);
+        }
+
+        // Clear the interrupt status bits
+        self.uart()
+            .irq_clr()
+            .write(|w| unsafe { w.bits(irq_end.bits()) });
+        result
+    }
+
+    /// This function should be called in the user provided UART interrupt handler.
+    ///
+    /// This function is used to read packets which either have a maximum size or variable sized
+    /// packet which are bounded by sufficient delays between them, triggering a hardware timeout.
+    ///
+    /// If either the maximum number of packets have been read or a timeout occured, the transfer
+    /// will be deemed completed. The state information of the transfer is tracked in the
+    /// [IrqContextTimeoutOrMaxSize] structure.
     ///
     /// If passed buffer is equal to or larger than the specified maximum length, an
-    /// [`Error::BufferTooShort`] will be returned
-    pub fn irq_handler(&mut self, buf: &mut [u8]) -> Result<IrqResult, IrqError> {
-        if buf.len() < self.irq_info.rx_len {
-            return Err(IrqError::BufferTooShort {
+    /// [BufferTooShortError] will be returned. Other RX errors are treated as partial errors
+    /// and returned inside the [IrqResultMaxSizeOrTimeout] structure.
+    pub fn irq_handler_max_size_or_timeout_based(
+        &mut self,
+        context: &mut IrqContextTimeoutOrMaxSize,
+        buf: &mut [u8],
+    ) -> Result<IrqResultMaxSizeOrTimeout, BufferTooShortError> {
+        if buf.len() < context.max_len {
+            return Err(BufferTooShortError {
                 found: buf.len(),
-                expected: self.irq_info.rx_len,
+                expected: context.max_len,
             });
         }
-        let mut res = IrqResult::default();
+        let mut result = IrqResultMaxSizeOrTimeout::default();
 
-        let irq_end = self.inner.0.irq_end().read();
-        let enb_status = self.inner.0.enable().read();
+        let irq_end = self.uart().irq_end().read();
+        let enb_status = self.uart().enable().read();
         let rx_enabled = enb_status.rxenable().bit_is_set();
 
         // Half-Full interrupt. We have a guaranteed amount of data we can read.
@@ -782,18 +956,18 @@ impl<Uart: Instance> RxWithIrq<Uart> {
             // We use this trick/hack because the timeout feature of the peripheral relies on data
             // being in the RX FIFO. If data continues arriving, another half-full IRQ will fire.
             // If not, the last byte(s) is/are emptied by the timeout interrupt.
-            let available_bytes = self.inner.0.rxfifoirqtrg().read().bits() as usize;
+            let available_bytes = self.uart().rxfifoirqtrg().read().bits() as usize;
 
             let bytes_to_read = core::cmp::min(
                 available_bytes.saturating_sub(1),
-                self.irq_info.rx_len - self.irq_info.rx_idx,
+                context.max_len - context.rx_idx,
             );
 
             // If this interrupt bit is set, the trigger level is available at the very least.
             // Read everything as fast as possible
             for _ in 0..bytes_to_read {
-                buf[self.irq_info.rx_idx] = (self.inner.0.data().read().bits() & 0xff) as u8;
-                self.irq_info.rx_idx += 1;
+                buf[context.rx_idx] = (self.uart().data().read().bits() & 0xff) as u8;
+                context.rx_idx += 1;
             }
 
             // On high-baudrates, data might be available immediately, and we possible have to
@@ -801,93 +975,96 @@ impl<Uart: Instance> RxWithIrq<Uart> {
             // rely on the hardware firing another IRQ. I have not tried baudrates higher than
             // 115200 so far.
         }
-        let read_handler =
-            |possible_error: &mut IrqUartError, read_res: nb::Result<u8, Error>| -> Option<u8> {
-                match read_res {
-                    Ok(byte) => Some(byte),
-                    Err(nb::Error::WouldBlock) => None,
-                    Err(nb::Error::Other(e)) => {
-                        match e {
-                            Error::Overrun => {
-                                possible_error.overflow = true;
-                            }
-                            Error::FramingError => {
-                                possible_error.framing = true;
-                            }
-                            Error::ParityError => {
-                                possible_error.parity = true;
-                            }
-                            _ => {
-                                possible_error.other = true;
-                            }
-                        }
-                        None
-                    }
-                }
-            };
         // Timeout, empty the FIFO completely.
         if irq_end.irq_rx_to().bit_is_set() {
             // While there is data in the FIFO, write it into the reception buffer
             loop {
-                if self.irq_info.rx_idx == self.irq_info.rx_len {
+                if context.rx_idx == context.max_len {
                     break;
                 }
-                if let Some(byte) = read_handler(&mut res.errors, self.inner.read()) {
-                    buf[self.irq_info.rx_idx] = byte;
-                    self.irq_info.rx_idx += 1;
+                let read_result = self.0.read();
+                if let Some(byte) = self.read_handler(&mut result.errors, &read_result) {
+                    buf[context.rx_idx] = byte;
+                    context.rx_idx += 1;
                 } else {
                     break;
                 }
             }
-            self.irq_completion_handler(&mut res);
-            return Ok(res);
+            self.irq_completion_handler_max_size_timeout(&mut result, context);
+            return Ok(result);
         }
 
         // RX transfer not complete, check for RX errors
-        if (self.irq_info.rx_idx < self.irq_info.rx_len) && rx_enabled {
-            // Read status register again, might have changed since reading received data
-            let rx_status = self.inner.0.rxstatus().read();
-            if rx_status.rxovr().bit_is_set() {
-                res.errors.overflow = true;
-            }
-            if rx_status.rxfrm().bit_is_set() {
-                res.errors.framing = true;
-            }
-            if rx_status.rxpar().bit_is_set() {
-                res.errors.parity = true;
-            }
-
-            // If it is not a timeout, it's an error
-            if res.error() {
-                self.disable_rx_irq_sources();
-                return Err(IrqError::Uart(res.errors));
-            }
+        if (context.rx_idx < context.max_len) && rx_enabled {
+            self.check_for_errors(&mut result.errors);
         }
 
         // Clear the interrupt status bits
-        self.inner
-            .0
+        self.uart()
             .irq_clr()
             .write(|w| unsafe { w.bits(irq_end.bits()) });
-        Ok(res)
+        Ok(result)
     }
 
-    fn irq_completion_handler(&mut self, res: &mut IrqResult) {
+    fn read_handler(
+        &self,
+        errors: &mut Option<IrqUartError>,
+        read_res: &nb::Result<u8, RxError>,
+    ) -> Option<u8> {
+        match read_res {
+            Ok(byte) => Some(*byte),
+            Err(nb::Error::WouldBlock) => None,
+            Err(nb::Error::Other(e)) => {
+                // Ensure `errors` is Some(IrqUartError), initializing if it's None
+                let err = errors.get_or_insert(IrqUartError::default());
+
+                // Now we can safely modify fields inside `err`
+                match e {
+                    RxError::Overrun => err.overflow = true,
+                    RxError::Framing => err.framing = true,
+                    RxError::Parity => err.parity = true,
+                }
+                None
+            }
+        }
+    }
+
+    fn check_for_errors(&self, errors: &mut Option<IrqUartError>) {
+        let rx_status = self.uart().rxstatus().read();
+
+        if rx_status.rxovr().bit_is_set()
+            || rx_status.rxfrm().bit_is_set()
+            || rx_status.rxpar().bit_is_set()
+        {
+            let err = errors.get_or_insert(IrqUartError::default());
+
+            if rx_status.rxovr().bit_is_set() {
+                err.overflow = true;
+            }
+            if rx_status.rxfrm().bit_is_set() {
+                err.framing = true;
+            }
+            if rx_status.rxpar().bit_is_set() {
+                err.parity = true;
+            }
+        }
+    }
+
+    fn irq_completion_handler_max_size_timeout(
+        &mut self,
+        res: &mut IrqResultMaxSizeOrTimeout,
+        context: &mut IrqContextTimeoutOrMaxSize,
+    ) {
         self.disable_rx_irq_sources();
-        self.inner.disable();
-        res.bytes_read = self.irq_info.rx_idx;
+        self.0.disable();
+        res.bytes_read = context.rx_idx;
         res.complete = true;
-        self.irq_info.mode = IrqReceptionMode::Idle;
-        self.irq_info.rx_idx = 0;
-        self.irq_info.rx_len = 0;
-    }
-
-    pub fn irq_info(&self) -> &IrqInfo {
-        &self.irq_info
+        context.mode = IrqReceptionMode::Idle;
+        context.rx_idx = 0;
     }
 
     pub fn release(self) -> Uart {
-        self.inner.release()
+        self.0.release()
     }
 }
 
@@ -897,18 +1074,34 @@ impl embedded_io::Error for Error {
     }
 }
 
+impl embedded_io::Error for RxError {
+    fn kind(&self) -> embedded_io::ErrorKind {
+        embedded_io::ErrorKind::Other
+    }
+}
+
 impl embedded_hal_nb::serial::Error for Error {
     fn kind(&self) -> embedded_hal_nb::serial::ErrorKind {
         embedded_hal_nb::serial::ErrorKind::Other
     }
 }
 
+impl embedded_hal_nb::serial::Error for RxError {
+    fn kind(&self) -> embedded_hal_nb::serial::ErrorKind {
+        match self {
+            RxError::Overrun => embedded_hal_nb::serial::ErrorKind::Overrun,
+            RxError::Framing => embedded_hal_nb::serial::ErrorKind::FrameFormat,
+            RxError::Parity => embedded_hal_nb::serial::ErrorKind::Parity,
+        }
+    }
+}
+
 impl<Uart> embedded_io::ErrorType for Rx<Uart> {
-    type Error = Error;
+    type Error = RxError;
 }
 
 impl<Uart> embedded_hal_nb::serial::ErrorType for Rx<Uart> {
-    type Error = Error;
+    type Error = RxError;
 }
 
 impl<Uart: Instance> embedded_hal_nb::serial::Read<u8> for Rx<Uart> {
@@ -916,11 +1109,11 @@ impl<Uart: Instance> embedded_hal_nb::serial::Read<u8> for Rx<Uart> {
         let uart = unsafe { &(*Uart::ptr()) };
         let status_reader = uart.rxstatus().read();
         let err = if status_reader.rxovr().bit_is_set() {
-            Some(Error::Overrun)
+            Some(RxError::Overrun)
         } else if status_reader.rxfrm().bit_is_set() {
-            Some(Error::FramingError)
+            Some(RxError::Framing)
         } else if status_reader.rxpar().bit_is_set() {
-            Some(Error::ParityError)
+            Some(RxError::Parity)
         } else {
             None
         };
@@ -929,14 +1122,15 @@ impl<Uart: Instance> embedded_hal_nb::serial::Read<u8> for Rx<Uart> {
             // and parity status bits. We have to read the DATA register
             // so that the next status reflects the next DATA word
             // For overrun error, we read as well to clear the peripheral
-            uart.data().read().bits();
-            Err(err.into())
-        } else if status_reader.rdavl().bit_is_set() {
-            let data = uart.data().read().bits();
-            Ok((data & 0xff) as u8)
-        } else {
-            Err(nb::Error::WouldBlock)
+            self.read_fifo_unchecked();
+            return Err(err.into());
         }
+        self.read_fifo().map(|val| (val & 0xff) as u8).map_err(|e| {
+            if let nb::Error::Other(_) = e {
+                unreachable!()
+            }
+            nb::Error::WouldBlock
+        })
     }
 }
 
@@ -956,28 +1150,16 @@ impl<Uart: Instance> embedded_io::Read for Rx<Uart> {
 }
 
 impl<Uart> embedded_io::ErrorType for Tx<Uart> {
-    type Error = Error;
+    type Error = Infallible;
 }
 
 impl<Uart> embedded_hal_nb::serial::ErrorType for Tx<Uart> {
-    type Error = Error;
+    type Error = Infallible;
 }
 
 impl<Uart: Instance> embedded_hal_nb::serial::Write<u8> for Tx<Uart> {
     fn write(&mut self, word: u8) -> nb::Result<(), Self::Error> {
-        let reader = unsafe { &(*Uart::ptr()) }.txstatus().read();
-        if reader.wrrdy().bit_is_clear() {
-            return Err(nb::Error::WouldBlock);
-        } else {
-            // DPARITY bit not supported yet
-            unsafe {
-                // NOTE(unsafe) atomic write to data register
-                // NOTE(write_volatile) 8-bit write that's not
-                // possible through the svd2rust API
-                (*Uart::ptr()).data().write(|w| w.bits(word as u32));
-            }
-        }
-        Ok(())
+        self.write_fifo(word as u32)
     }
 
     fn flush(&mut self) -> nb::Result<(), Self::Error> {
@@ -1020,16 +1202,26 @@ impl<UartInstance> embedded_hal_nb::serial::ErrorType for UartBase<UartInstance>
 
 impl<Uart: Instance> embedded_hal_nb::serial::Read<u8> for UartBase<Uart> {
     fn read(&mut self) -> nb::Result<u8, Self::Error> {
-        self.rx.read()
+        self.rx.read().map_err(|e| e.map(Error::Rx))
     }
 }
 
 impl<Uart: Instance> embedded_hal_nb::serial::Write<u8> for UartBase<Uart> {
     fn write(&mut self, word: u8) -> nb::Result<(), Self::Error> {
-        self.tx.write(word)
+        self.tx.write(word).map_err(|e| {
+            if let nb::Error::Other(_) = e {
+                unreachable!()
+            }
+            nb::Error::WouldBlock
+        })
     }
 
     fn flush(&mut self) -> nb::Result<(), Self::Error> {
-        self.tx.flush()
+        self.tx.flush().map_err(|e| {
+            if let nb::Error::Other(_) = e {
+                unreachable!()
+            }
+            nb::Error::WouldBlock
+        })
     }
 }

vscode/launch.json

@@ -350,6 +350,36 @@
                 ]
             }
         },
+        {
+            "type": "cortex-debug",
+            "request": "launch",
+            "name": "UART Echo with IRQ",
+            "servertype": "jlink",
+            "jlinkscript": "${workspaceFolder}/jlink/JLinkSettings.JLinkScript",
+            "cwd": "${workspaceRoot}",
+            "device": "Cortex-M4",
+            "svdFile": "${workspaceFolder}/va416xx/svd/va416xx.svd.patched",
+            "preLaunchTask": "uart-echo-with-irq",
+            "overrideLaunchCommands": [
+                "monitor halt",
+                "monitor reset",
+                "load",
+            ],
+            "executable": "${workspaceFolder}/target/thumbv7em-none-eabihf/debug/uart-echo-with-irq",
+            "interface": "swd",
+            "runToEntryPoint": "main",
+            "rttConfig": {
+                "enabled": true,
+                "address": "auto",
+                "decoders": [
+                    {
+                        "port": 0,
+                        "timestamp": true,
+                        "type": "console"
+                    }
+                ]
+            }
+        },
         {
             "type": "cortex-debug",
             "request": "launch",

vscode/tasks.json

@@ -95,6 +95,19 @@
                 "kind": "build",
             }
         },
+        {
+            "label": "uart-echo-with-irq",
+            "type": "shell",
+            "command": "~/.cargo/bin/cargo", // note: full path to the cargo
+            "args": [
+                "build",
+                "--bin",
+                "uart-echo-with-irq"
+            ],
+            "group": {
+                "kind": "build",
+            }
+        },
         {
             "label": "pwm-example",
             "type": "shell",