bootloader/src/main.rs

@@ -45,17 +45,26 @@ const BOOTLOADER_START_ADDR: u32 = 0x0;
 const BOOTLOADER_CRC_ADDR: u32 = BOOTLOADER_END_ADDR - 4;
 const BOOTLOADER_END_ADDR: u32 = 0x4000;
 
-const APP_A_START_ADDR: u32 = BOOTLOADER_END_ADDR; // 0x4000
-// The actual size of the image which is relevant for CRC calculation.
-const APP_A_SIZE_ADDR: u32 = APP_B_END_ADDR - 8; // 0x21FF8
-const APP_A_CRC_ADDR: u32 = APP_B_END_ADDR - 4; // 0x21FFC
+// 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;
 
-const APP_B_START_ADDR: u32 = APP_A_END_ADDR; //  0x22000
-// The actual size of the image which is relevant for CRC calculation.
-const APP_B_SIZE_ADDR: u32 = APP_B_END_ADDR - 8; // 0x3FFF8
-const APP_B_CRC_ADDR: u32 = APP_B_END_ADDR - 4; // 0x3FFFC
-pub const APP_B_END_ADDR: u32 = NVM_SIZE; // 0x40000
+//  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;
 

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/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>,
@@ -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() {
@@ -279,7 +290,7 @@ 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() {
@@ -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

@@ -13,6 +13,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - 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
 

va416xx-hal/src/uart.rs

@@ -1,5 +1,9 @@
 //! # 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)
@@ -198,25 +202,49 @@ 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: IrqUartError,
+}
+
+/// This struct is used to return the default IRQ handler result to the user
+#[derive(Debug, Default)]
+pub struct IrqResultMaxSizeTimeout {
     complete: bool,
     timeout: bool,
     pub errors: IrqUartError,
     pub bytes_read: usize,
 }
 
-impl IrqResult {
+impl IrqResultMaxSizeTimeout {
     pub fn new() -> Self {
-        IrqResult {
+        IrqResultMaxSizeTimeout {
             complete: false,
             timeout: false,
             errors: IrqUartError::default(),
@@ -224,7 +252,7 @@ impl IrqResult {
         }
     }
 }
-impl IrqResult {
+impl IrqResultMaxSizeTimeout {
     #[inline]
     pub fn error(&self) -> bool {
         if self.errors.overflow || self.errors.parity || self.errors.framing {
@@ -259,7 +287,7 @@ impl IrqResult {
     }
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Copy, Clone)]
 enum IrqReceptionMode {
     Idle,
     Pending,
@@ -281,16 +309,14 @@ pub struct Uart<UartInstance, Pins> {
     pins: Pins,
 }
 
-/// Serial receiver
+/// Serial receiver.
+///
+/// Can be created by using the [Uart::split] or [UartBase::split] API.
 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
+///
+/// Can be created by using the [Uart::split] or [UartBase::split] API.
 pub struct Tx<Uart>(Uart);
 
 impl<Uart: Instance> Rx<Uart> {
@@ -551,33 +577,6 @@ 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 +603,6 @@ 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,
@@ -651,6 +641,10 @@ impl<Uart: Instance> Rx<Uart> {
         self.0.enable().modify(|_, w| w.rxenable().clear_bit());
     }
 
+    pub fn to_rx_with_irq(self) -> RxWithIrq<Uart> {
+        RxWithIrq(self)
+    }
+
     pub fn release(self) -> Uart {
         self.0
     }
@@ -691,6 +685,29 @@ 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
     }
@@ -702,35 +719,62 @@ pub enum IrqError {
     Uart(IrqUartError),
 }
 
+/// 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.
+    /// 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.
     ///
-    /// 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(
+    /// 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,
-        max_len: usize,
-        enb_timeout_irq: bool,
+        context: &mut IrqContextTimeoutOrMaxSize,
     ) -> Result<(), Error> {
-        if self.irq_info.mode != IrqReceptionMode::Idle {
+        if context.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);
-        unsafe { enable_interrupt(Uart::IRQ_RX) };
+        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 +785,7 @@ 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 +794,22 @@ 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
-    }
-
-    /// Default IRQ handler which can be used to read the packets arriving on the UART peripheral.
+    /// This function should be called in the user provided UART interrupt handler.
     ///
-    /// 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 {
-                found: buf.len(),
-                expected: self.irq_info.rx_len,
-            });
-        }
-        let mut res = IrqResult::default();
+    /// 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.
+    pub fn irq_handler(&mut self, buf: &mut [u8; 16]) -> Result<IrqResult, IrqUartError> {
+        let mut result = IrqResult::default();
+        let mut current_idx = 0;
 
-        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 +818,84 @@ 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;
+
+            // 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[current_idx] = (self.uart().data().read().bits() & 0xff) as u8;
+                current_idx += 1;
+            }
+        }
+
+        // Timeout, empty the FIFO completely.
+        if irq_end.irq_rx_to().bit_is_set() {
+            let read_result = self.0.read();
+            // While there is data in the FIFO, write it into the reception buffer
+            while let Some(byte) = self.read_handler(&mut result.errors, &read_result) {
+                buf[current_idx] = byte;
+                current_idx += 1;
+            }
+        }
+
+        // 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()) });
+        Ok(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_max_size_or_timeout_based(
+        &mut self,
+        context: &mut IrqContextTimeoutOrMaxSize,
+        buf: &mut [u8],
+    ) -> Result<IrqResultMaxSizeTimeout, IrqError> {
+        if buf.len() < context.max_len {
+            return Err(IrqError::BufferTooShort {
+                found: buf.len(),
+                expected: context.max_len,
+            });
+        }
+        let mut result = IrqResultMaxSizeTimeout::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() {
+            // Determine the number of bytes to read, ensuring we leave 1 byte in the FIFO.
+            // 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.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 +903,94 @@ 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> {
+        // 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 context.rx_idx == context.max_len {
+                    break;
+                }
+                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_max_size_timeout(&mut result, context);
+            return Ok(result);
+        }
+
+        // RX transfer not complete, check for RX errors
+        if (context.rx_idx < context.max_len) && 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()) });
+        Ok(result)
+    }
+
+    fn read_handler(
+        &self,
+        errors: &mut IrqUartError,
+        read_res: &nb::Result<u8, Error>,
+    ) -> Option<u8> {
         match read_res {
-                    Ok(byte) => Some(byte),
+            Ok(byte) => Some(*byte),
             Err(nb::Error::WouldBlock) => None,
             Err(nb::Error::Other(e)) => {
                 match e {
                     Error::Overrun => {
-                                possible_error.overflow = true;
+                        errors.overflow = true;
                     }
                     Error::FramingError => {
-                                possible_error.framing = true;
+                        errors.framing = true;
                     }
                     Error::ParityError => {
-                                possible_error.parity = true;
+                        errors.parity = true;
                     }
                     _ => {
-                                possible_error.other = true;
+                        errors.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 {
-                    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;
-                } else {
-                    break;
-                }
-            }
-            self.irq_completion_handler(&mut res);
-            return Ok(res);
     }
 
-        // RX transfer not complete, check for RX errors
-        if (self.irq_info.rx_idx < self.irq_info.rx_len) && rx_enabled {
+    fn check_for_errors(&self, errors: &mut IrqUartError) {
         // Read status register again, might have changed since reading received data
-            let rx_status = self.inner.0.rxstatus().read();
+        let rx_status = self.uart().rxstatus().read();
         if rx_status.rxovr().bit_is_set() {
-                res.errors.overflow = true;
+            errors.overflow = true;
         }
         if rx_status.rxfrm().bit_is_set() {
-                res.errors.framing = true;
+            errors.framing = true;
         }
         if rx_status.rxpar().bit_is_set() {
-                res.errors.parity = true;
+            errors.parity = true;
+        }
     }
 
-            // If it is not a timeout, it's an error
-            if res.error() {
+    fn irq_completion_handler_max_size_timeout(
+        &mut self,
+        res: &mut IrqResultMaxSizeTimeout,
+        context: &mut IrqContextTimeoutOrMaxSize,
+    ) {
         self.disable_rx_irq_sources();
-                return Err(IrqError::Uart(res.errors));
-            }
-        }
-
-        // Clear the interrupt status bits
-        self.inner
-            .0
-            .irq_clr()
-            .write(|w| unsafe { w.bits(irq_end.bits()) });
-        Ok(res)
-    }
-
-    fn irq_completion_handler(&mut self, res: &mut IrqResult) {
-        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()
     }
 }