README: general update

README.md

@@ -4,60 +4,92 @@ ARTIQ on Zynq
 How to use
 ----------
 
-1. Install the ARTIQ version that corresponds to the artiq-zynq version you are targeting.
-2. To obtain firmware binaries, select the latest successful build on [Hydra](https://nixbld.m-labs.hk/) for the targeted artiq-zynq version, or use AFWS. If using Hydra, search for the job named ``<board>-<variant>-sd`` (for example: ``zc706-nist_clock-sd`` or ``zc706-nist_qc2-sd``).
-3. Place the ``boot.bin`` file, obtained from Hydra's "binary distribution" download link or from AFWS, at the root of a FAT-formatted SD card.
-4. Optionally, create a ``config.txt`` configuration file at the root of the SD card containing ``key=value`` pairs on each line. Use the ``ip``, ``ip6`` and ``mac`` keys to respectively set the IPv4, IPv6 and MAC address of the board. Configuring an IPv6 address is entirely optional. If these keys are not found, the firmware will use default values that may or may not be compatible with your network.
-5. Insert the SD card into the board and set up the board to boot from the SD card. For the ZC706, this is achieved by placing the large DIP switch SW11 in the 00110 position.
-6. Power up the board. After the firmware starts successfully, it should respond to ping at its IP addresses, and boot messages can be observed from its UART at 115200bps.
-7. Create and use an ARTIQ device database as usual, but set ``"target": "cortexa9"`` in the arguments of the core device.
+1. [Install ARTIQ](https://m-labs.hk/artiq/manual/installing.html). Get the corresponding version to the ``artiq-zynq`` version you are targeting.
+2. To obtain firmware binaries, use AFWS or build your own; see [the ARTIQ manual](https://m-labs.hk/artiq/manual/building_developing.html) for detailed instructions or skip to "Development" below. ZC706 variants only can also be downloaded from latest successful build on [Hydra](https://nixbld.m-labs.hk/).
+3. Place ``boot.bin`` file at the root ``/`` of a FAT-formatted SD card.
+4. Optionally, create a ``config.txt`` configuration file containing ``key=value`` pairs on each line and place it at the root of the SD card. See below for valid keys. The ``ip``, ``ip6`` and ``mac`` keys can be used to set networking information. If these keys are not found, the firmware will use default values which may or may not be compatible with your network.
+5. Insert the SD card into the board and set the board to boot from the SD card. For ZC706, this is achieved by placing the large DIP switch SW11 into the 00110 position. On Kasli-SoC, place the BOOT MODE switches to SD.
+6. Power up the board. After successful boot the firmware should respond to ping at its IP addresses. Boot output can be observed from UART at 115200bps 8-N-1.
+7. Create and use an ARTIQ device database as usual.
 
 Configuration
 -------------
 
-Configuring the device is done using the ``config.txt`` text file at the root of the SD card, plus the contents of the ``config`` folder. When searching for a configuration key, the firmware first looks for a file named ``/config/[key].bin`` and, if it exists, returns the contents of that file. If not, it looks into ``/config.txt``, which contains a list of ``key=value`` pairs, one per line. The ``config`` folder allows configuration values that consist in binary data, such as the startup kernel.
+Configuring the device is done using the ``config.txt`` text file at the root of the SD card plus optionally a ``config`` folder. When searching for a configuration key, the firmware first looks for a file named ``/config/[key].bin`` and, if it exists, returns the contents of that file. If not, it looks into ``/config.txt``, which should contain a list of ``key=value`` pairs, one per line. ``config.txt`` should be used for most keys but the ``config`` folder allows for setting configuration values which consist of binary data, such as the startup kernel.
 
-The following configuration keys are available:
+The following configuration keys are available among others:
 
 - ``mac``: Ethernet MAC address.
 - ``ip``: IPv4 address.
 - ``ip6``: IPv6 address.
-- ``startup``: startup kernel in ELF format (as produced by ``artiq_compile``).
+- ``idle_kernel``: idle kernel in ELF format (as produced by ``artiq_compile``).
+- ``startup_kernel``: startup kernel in ELF format (as produced by ``artiq_compile``).
 - ``rtio_clock``: source of RTIO clock; valid values are ``ext0_bypass`` and ``int_125``.
-- ``boot``: SD card "boot.bin" file, for replacing the boot firmware/gateware. Write only.
 
-Configurations can be read/written/removed via ``artiq_coremgmt``. Config erase is
-not implemented as it seems not very useful.
+See [ARTIQ manual](https://m-labs.hk/artiq/manual-beta/core_device.html#configuration-storage) for full list. Configurations can be read/written/removed with ``artiq_coremgmt``. Config erase is not implemented, as it isn't particularly useful.
+
+For convenience, the ``boot`` key can be used with ``artiq_coremgmt`` and a ``boot.bin`` file to replace firmware/gateware in a running system. This key is read-only. When loading ``boot.bin`` onto the SD card directly, place it at the root and not in the ``config`` folder.
 
 Development instructions
 ------------------------
 
-ARTIQ on Zynq is packaged using the [Nix](https://nixos.org) Flakes system. Install Nix 2.8+ and enable flakes by adding ``experimental-features = nix-command flakes`` to ``nix.conf`` (e.g. ``~/.config/nix/nix.conf``).
+ARTIQ on Zynq is packaged using [Nix](https://nixos.org) Flakes. Install Nix 2.8+ and enable flakes by adding ``experimental-features = nix-command flakes`` to ``nix.conf`` (e.g. ``~/.config/nix/nix.conf``).
 
-Pure build with Nix and execution on a remote JTAG server:
+**Pure build with Nix:**
 
 ```shell
-nix build .#zc706-nist_clock-jtag  # or zc706-nist_qc2-jtag or zc706-nist_clock_satellite-jtag etc.
-./remote_run.sh
+nix build .#zc706-nist_clock-jtag  # or zc706-nist_qc2-jtag or zc706-nist_clock-sd or etc
 ```
 
-Impure incremental build and execution on a remote JTAG server:
+Run ``nix flake show`` to see all valid build targets. Targets suffixed with ``-jtag`` produce separate firmware and gateware files, intended for use in booting via JTAG server/Ethernet, e.g. ``./remote_run.sh -i`` with a remote JTAG server. Targets suffixed with ``-sd`` will produce ``boot.bin`` file suitable for SD card boot. ``-firmware`` and ``-gateware`` respectively build firmware and gateware only.
+
+The Kasli-SoC target requires a system description file as input. See ARTIQ manual for exact instructions or use incremental build.
+
+**Impure incremental build:**
+
+For boards with fixed variants, i.e. ZC706, etc. :
 
 ```shell
 nix develop
 cd src
-gateware/zc706.py -g ../build/gateware -V <variant> # build gateware
-make GWARGS="-V <variant>" <runtime/satman>    # build firmware
-cd ..
-./remote_run.sh -i
+gateware/<board>.py -g ../build/gateware -V <variant> # gateware
+make GWARGS="-V <variant>" <runtime/satman>    # firmware
+```
+
+For boards with system descriptions, i.e. Kasli-SoC, etc. :
+
+```shell
+nix develop
+cd src
+gateware/<board>.py -g ../build/gateware <description.json> # gateware
+make TARGET=<board> GWARGS="path/to/description.json" <runtime/satman> # firmware
+```
+
+``szl.elf`` can be obtained with:
+
+```shell
+nix build git+https://git.m-labs.hk/m-labs/zynq-rs#<board>-szl
+```
+
+To generate ``boot.bin`` use ``mkbootimage``, e.g.:
+
+```shell
+echo "the_ROM_image:
+    {
+        [bootloader]result/szl.elf
+        gateware/top.bit
+        firmware/armv7-none-eabihf/release/<runtime/satman>
+    }
+    EOF" >> boot.bif
+mkbootimage boot.bif boot.bin
 ```
 
 Notes:
 
 - The impure build process is also compatible with non-Nix systems.
-- When calling make, you need to specify both the variant and firmware type.
 - Firmware type must be either ``runtime`` for DRTIO-less or DRTIO master variants, or ``satman`` for DRTIO satellite.
-- If the board is connected to the local machine, use the ``local_run.sh`` script.
+- If the board is connected to the local machine by JTAG, use the ``local_run.sh`` script.
+- A known Xilinx hardware bug prevents repeatedly loading the bootloader over JTAG without a POR reset. If booting over JTAG, install a jumper on ``PS_POR_B`` and use the POR reset script [here](https://git.m-labs.hk/M-Labs/zynq-rs/src/branch/master/kasli_soc_por.py).
 
 License
 -------

flake.lock

@@ -11,15 +11,16 @@
         "src-pythonparser": "src-pythonparser"
       },
       "locked": {
-        "lastModified": 1717638354,
-        "narHash": "sha256-eyI8OsOrn/j8ChbCpyFpS5VXBW8xSNGGIboFGQj/d4I=",
-        "ref": "refs/heads/master",
-        "rev": "ebc1e3fb767d6c0eac6eac20c3afeaba2ab70d1a",
-        "revCount": 8833,
+        "lastModified": 1724402779,
+        "narHash": "sha256-mWaCa1AMsUbL+1rIfPB359LUAMQea8Krtctbu901rdY=",
+        "ref": "release-8",
+        "rev": "4235309ab75519aee98d06f942c8cb90fba94af7",
+        "revCount": 8954,
         "type": "git",
         "url": "https://github.com/m-labs/artiq.git"
       },
       "original": {
+        "ref": "release-8",
         "type": "git",
         "url": "https://github.com/m-labs/artiq.git"
       }
@@ -37,11 +38,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1717637438,
-        "narHash": "sha256-BXFidNm3Em8iChPGu1L0s2bY+f2yQ0VVid4MuOoTehw=",
+        "lastModified": 1720768567,
+        "narHash": "sha256-3VoK7o5MtHtbHLrc6Pv+eQWFtaz5Gd/YWyV5TD3c5Ss=",
         "owner": "m-labs",
         "repo": "artiq-comtools",
-        "rev": "78d27026efe76a13f7b4698a554f55811369ec4d",
+        "rev": "f93570d8f2ed5a3cfb3e1c16ab00f2540551e994",
         "type": "github"
       },
       "original": {
@@ -118,11 +119,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1717281328,
-        "narHash": "sha256-evZPzpf59oNcDUXxh2GHcxHkTEG4fjae2ytWP85jXRo=",
+        "lastModified": 1722987190,
+        "narHash": "sha256-68hmex5efCiM2aZlAAEcQgmFI4ZwWt8a80vOeB/5w3A=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "b3b2b28c1daa04fe2ae47c21bb76fd226eac4ca1",
+        "rev": "21cc704b5e918c5fbf4f9fff22b4ac2681706d90",
         "type": "github"
       },
       "original": {
@@ -163,11 +164,11 @@
     "src-migen": {
       "flake": false,
       "locked": {
-        "lastModified": 1715484909,
-        "narHash": "sha256-4DCHBUBfc/VA+7NW2Hr0+JP4NnKPru2uVJyZjCCk0Ws=",
+        "lastModified": 1721561053,
+        "narHash": "sha256-z3LRhNmKZrjr6rFD0yxtccSa/SWvFIYmb+G/D5d2Jd8=",
         "owner": "m-labs",
         "repo": "migen",
-        "rev": "4790bb577681a8c3a8d226bc196a4e5deb39e4df",
+        "rev": "9279e8623f8433bc4f23ac51e5e2331bfe544417",
         "type": "github"
       },
       "original": {
@@ -234,11 +235,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1716889070,
-        "narHash": "sha256-w+M5NfukmcMTt73+u6Cmltjn4qpQH8bcoTGskB2IzBE=",
+        "lastModified": 1720537402,
+        "narHash": "sha256-ybvaQ48SVBqYVqgYmGUdefGZkni7PJ90qYQPHnFOwDs=",
         "ref": "refs/heads/master",
-        "rev": "51b8111e799ebe90ca231ae4d02f84ede32632d5",
-        "revCount": 646,
+        "rev": "b2b3e5c933cbc4b7cb14adde480d7561a3ae71ee",
+        "revCount": 648,
         "type": "git",
         "url": "https://git.m-labs.hk/m-labs/zynq-rs"
       },

flake.nix

@@ -1,7 +1,7 @@
 {
   description = "ARTIQ port to the Zynq-7000 platform";
 
-  inputs.artiq.url = git+https://github.com/m-labs/artiq.git;
+  inputs.artiq.url = git+https://github.com/m-labs/artiq.git?ref=release-8;
   inputs.mozilla-overlay = { url = github:mozilla/nixpkgs-mozilla; flake = false; };
   inputs.zynq-rs.url = git+https://git.m-labs.hk/m-labs/zynq-rs;
   inputs.zynq-rs.inputs.nixpkgs.follows = "artiq/nixpkgs";

src/gateware/kasli_soc.py

@@ -560,7 +560,10 @@ class GenericSatellite(SoCCore):
         self.submodules.local_io = SyncRTIO(
             self.rtio_tsc, self.rtio_channels, lane_count=description["sed_lanes"]
         )
-        self.comb += self.drtiosat.async_errors.eq(self.local_io.async_errors)
+        self.comb += [
+            self.drtiosat.async_errors.eq(self.local_io.async_errors),
+            self.local_io.sed_spread_enable.eq(self.drtiosat.sed_spread_enable.storage)
+        ]
 
         self.submodules.cri_con = rtio.CRIInterconnectShared(
             [self.drtiosat.cri, self.rtio_dma.cri, self.rtio.cri],

src/gateware/zc706.py

@@ -487,6 +487,10 @@ class _SatelliteBase(SoCCore):
         self.csr_devices.append("rtio_dma")
 
         self.submodules.local_io = SyncRTIO(self.rtio_tsc, rtio_channels)
+        self.comb += [
+            self.drtiosat.async_errors.eq(self.local_io.async_errors),
+            self.local_io.sed_spread_enable.eq(self.drtiosat.sed_spread_enable.storage)
+        ]
         self.submodules.cri_con = rtio.CRIInterconnectShared(
             [self.drtiosat.cri, self.rtio_dma.cri, self.rtio.cri],
             [self.local_io.cri] + self.drtio_cri,

src/libboard_artiq/src/drtioaux_proto.rs

@@ -255,6 +255,7 @@ pub enum Packet {
         destination: u8,
         id: u32,
         run: bool,
+        timestamp: u64,
     },
     SubkernelLoadRunReply {
         destination: u8,
@@ -267,12 +268,14 @@ pub enum Packet {
         exception_src: u8,
     },
     SubkernelExceptionRequest {
+        source: u8,
         destination: u8,
     },
     SubkernelException {
+        destination: u8,
         last: bool,
         length: u16,
-        data: [u8; SAT_PAYLOAD_MAX_SIZE],
+        data: [u8; MASTER_PAYLOAD_MAX_SIZE],
     },
     SubkernelMessage {
         source: u8,
@@ -512,6 +515,7 @@ impl Packet {
                 destination: reader.read_u8()?,
                 id: reader.read_u32()?,
                 run: reader.read_bool()?,
+                timestamp: reader.read_u64()?,
             },
             0xc5 => Packet::SubkernelLoadRunReply {
                 destination: reader.read_u8()?,
@@ -524,14 +528,17 @@ impl Packet {
                 exception_src: reader.read_u8()?,
             },
             0xc9 => Packet::SubkernelExceptionRequest {
+                source: reader.read_u8()?,
                 destination: reader.read_u8()?,
             },
             0xca => {
+                let destination = reader.read_u8()?;
                 let last = reader.read_bool()?;
                 let length = reader.read_u16()?;
-                let mut data: [u8; SAT_PAYLOAD_MAX_SIZE] = [0; SAT_PAYLOAD_MAX_SIZE];
+                let mut data: [u8; MASTER_PAYLOAD_MAX_SIZE] = [0; MASTER_PAYLOAD_MAX_SIZE];
                 reader.read_exact(&mut data[0..length as usize])?;
                 Packet::SubkernelException {
+                    destination: destination,
                     last: last,
                     length: length,
                     data: data,
@@ -872,12 +879,14 @@ impl Packet {
                 destination,
                 id,
                 run,
+                timestamp,
             } => {
                 writer.write_u8(0xc4)?;
                 writer.write_u8(source)?;
                 writer.write_u8(destination)?;
                 writer.write_u32(id)?;
                 writer.write_bool(run)?;
+                writer.write_u64(timestamp)?;
             }
             Packet::SubkernelLoadRunReply { destination, succeeded } => {
                 writer.write_u8(0xc5)?;
@@ -896,12 +905,19 @@ impl Packet {
                 writer.write_bool(with_exception)?;
                 writer.write_u8(exception_src)?;
             }
-            Packet::SubkernelExceptionRequest { destination } => {
+            Packet::SubkernelExceptionRequest { source, destination } => {
                 writer.write_u8(0xc9)?;
+                writer.write_u8(source)?;
                 writer.write_u8(destination)?;
             }
-            Packet::SubkernelException { last, length, data } => {
+            Packet::SubkernelException {
+                destination,
+                last,
+                length,
+                data,
+            } => {
                 writer.write_u8(0xca)?;
+                writer.write_u8(destination)?;
                 writer.write_bool(last)?;
                 writer.write_u16(length)?;
                 writer.write_all(&data[0..length as usize])?;
@@ -943,6 +959,8 @@ impl Packet {
             Packet::SubkernelLoadRunReply { destination, .. } => Some(*destination),
             Packet::SubkernelMessage { destination, .. } => Some(*destination),
             Packet::SubkernelMessageAck { destination } => Some(*destination),
+            Packet::SubkernelExceptionRequest { destination, .. } => Some(*destination),
+            Packet::SubkernelException { destination, .. } => Some(*destination),
             Packet::DmaPlaybackStatus { destination, .. } => Some(*destination),
             Packet::SubkernelFinished { destination, .. } => Some(*destination),
             _ => None,

src/libksupport/src/eh_artiq.rs

@@ -14,8 +14,10 @@
 
 use core::mem;
 
-use cslice::CSlice;
+use core_io::Error as ReadError;
+use cslice::{AsCSlice, CSlice};
 use dwarf::eh::{self, EHAction, EHContext};
+use io::{Cursor, ProtoRead};
 use libc::{c_int, c_void, uintptr_t};
 use log::{error, trace};
 use unwind as uw;
@@ -220,8 +222,6 @@ pub unsafe fn artiq_personality(
 }
 
 pub unsafe extern "C" fn raise(exception: *const Exception) -> ! {
-    use cslice::AsCSlice;
-
     let count = EXCEPTION_BUFFER.exception_count;
     let stack = &mut EXCEPTION_BUFFER.exception_stack;
     let diff = exception as isize - EXCEPTION_BUFFER.exceptions.as_ptr() as isize;
@@ -295,6 +295,60 @@ pub unsafe extern "C" fn raise(exception: *const Exception) -> ! {
     unreachable!();
 }
 
+fn read_exception_string<'a>(reader: &mut Cursor<&[u8]>) -> Result<CSlice<'a, u8>, ReadError> {
+    let len = reader.read_u32()? as usize;
+    if len == usize::MAX {
+        let data = reader.read_u32()?;
+        Ok(unsafe { CSlice::new(data as *const u8, len) })
+    } else {
+        let pos = reader.position();
+        let slice = unsafe {
+            let ptr = reader.get_ref().as_ptr().offset(pos as isize);
+            CSlice::new(ptr, len)
+        };
+        reader.set_position(pos + len);
+        Ok(slice)
+    }
+}
+
+fn read_exception(raw_exception: &[u8]) -> Result<Exception, ReadError> {
+    let mut reader = Cursor::new(raw_exception);
+
+    let mut byte = reader.read_u8()?;
+    // to sync
+    while byte != 0x5a {
+        byte = reader.read_u8()?;
+    }
+    // skip sync bytes, 0x09 indicates exception
+    while byte != 0x09 {
+        byte = reader.read_u8()?;
+    }
+    let _len = reader.read_u32()?;
+    // ignore the remaining exceptions, stack traces etc. - unwinding from another device would be unwise anyway
+    Ok(Exception {
+        id: reader.read_u32()?,
+        message: read_exception_string(&mut reader)?,
+        param: [
+            reader.read_u64()? as i64,
+            reader.read_u64()? as i64,
+            reader.read_u64()? as i64,
+        ],
+        file: read_exception_string(&mut reader)?,
+        line: reader.read_u32()?,
+        column: reader.read_u32()?,
+        function: read_exception_string(&mut reader)?,
+    })
+}
+
+pub fn raise_raw(raw_exception: &[u8]) -> ! {
+    use crate::artiq_raise;
+    if let Ok(exception) = read_exception(raw_exception) {
+        unsafe { raise(&exception) };
+    } else {
+        artiq_raise!("SubkernelError", "Error passing exception");
+    }
+}
+
 pub unsafe extern "C" fn resume() -> ! {
     trace!("resume");
     assert!(EXCEPTION_BUFFER.exception_count != 0);
@@ -421,7 +475,7 @@ extern "C" fn stop_fn(
     }
 }
 
-// Must be kept in sync with preallocate_runtime_exception_names() in artiq/language/embedding_map.py
+// Must be kept in sync with preallocate_runtime_exception_names() in `artiq.compiler.embedding`
 static EXCEPTION_ID_LOOKUP: [(&str, u32); 12] = [
     ("RuntimeError", 0),
     ("RTIOUnderflow", 1),
@@ -469,3 +523,29 @@ macro_rules! artiq_raise {
     }};
     ($name:expr, $message:expr) => {{ artiq_raise!($name, $message, 0, 0, 0) }};
 }
+
+/// Takes as input exception id from host
+/// Generates a new exception with:
+///   * `id` set to `exn_id`
+///   * `message` set to corresponding exception name from `EXCEPTION_ID_LOOKUP`
+///
+/// The message is matched on host to ensure correct exception is being referred
+/// This test checks the synchronization of exception ids for runtime errors
+#[no_mangle]
+pub extern "C" fn test_exception_id_sync(exn_id: u32) {
+    let message = EXCEPTION_ID_LOOKUP
+        .iter()
+        .find_map(|&(name, id)| if id == exn_id { Some(name) } else { None })
+        .unwrap_or("unallocated internal exception id");
+
+    let exn = Exception {
+        id: exn_id,
+        file: file!().as_c_slice(),
+        line: 0,
+        column: 0,
+        function: "test_exception_id_sync".as_c_slice(),
+        message: message.as_c_slice(),
+        param: [0, 0, 0],
+    };
+    unsafe { raise(&exn) };
+}

src/libksupport/src/kernel/api.rs

@@ -303,6 +303,7 @@ pub fn resolve(required: &[u8]) -> Option<u32> {
         api_libm_f64f64f64!(nextafter),
         api_libm_f64f64f64!(pow),
         api_libm_f64f64!(round),
+        api_libm_f64f64!(rint),
         api_libm_f64f64!(sin),
         api_libm_f64f64!(sinh),
         api_libm_f64f64!(sqrt),
@@ -318,6 +319,13 @@ pub fn resolve(required: &[u8]) -> Option<u32> {
             }
             api!(yn = yn)
         },
+        /*
+         * syscall for unit tests
+         * Used in `artiq.tests.coredevice.test_exceptions.ExceptionTest.test_raise_exceptions_kernel`
+         * This syscall checks that the exception IDs used in the Python `EmbeddingMap` (in `artiq.language.embedding`)
+         * match the `EXCEPTION_ID_LOOKUP` defined in the firmware (`libksupport::src::eh_artiq`)
+         */
+        api!(test_exception_id_sync = eh_artiq::test_exception_id_sync)
     ];
     api.iter()
         .find(|&&(exported, _)| exported.as_bytes() == required)

src/libksupport/src/kernel/mod.rs

@@ -23,6 +23,7 @@ pub enum SubkernelStatus {
     Timeout,
     IncorrectState,
     CommLost,
+    Exception(Vec<u8>),
     OtherError,
 }
 
@@ -79,6 +80,7 @@ pub enum Message {
         id: u32,
         destination: u8,
         run: bool,
+        timestamp: u64,
     },
     #[cfg(has_drtio)]
     SubkernelLoadRunReply {
@@ -90,9 +92,7 @@ pub enum Message {
         timeout: i64,
     },
     #[cfg(has_drtio)]
-    SubkernelAwaitFinishReply {
-        status: SubkernelStatus,
-    },
+    SubkernelAwaitFinishReply,
     #[cfg(has_drtio)]
     SubkernelMsgSend {
         id: u32,
@@ -109,9 +109,10 @@ pub enum Message {
     },
     #[cfg(has_drtio)]
     SubkernelMsgRecvReply {
-        status: SubkernelStatus,
         count: u8,
     },
+    #[cfg(has_drtio)]
+    SubkernelError(SubkernelStatus),
 }
 
 static CHANNEL_0TO1: Mutex<Option<sync_channel::Sender<'static, Message>>> = Mutex::new(None);

src/libksupport/src/kernel/subkernel.rs

@@ -3,7 +3,7 @@ use alloc::vec::Vec;
 use cslice::CSlice;
 
 use super::{Message, SubkernelStatus, KERNEL_CHANNEL_0TO1, KERNEL_CHANNEL_1TO0};
-use crate::{artiq_raise, rpc::send_args};
+use crate::{artiq_raise, eh_artiq, rpc::send_args, rtio::now_mu};
 
 pub extern "C" fn load_run(id: u32, destination: u8, run: bool) {
     unsafe {
@@ -14,6 +14,7 @@ pub extern "C" fn load_run(id: u32, destination: u8, run: bool) {
                 id: id,
                 destination: destination,
                 run: run,
+                timestamp: now_mu() as u64,
             });
     }
     match unsafe { KERNEL_CHANNEL_0TO1.as_mut().unwrap() }.recv() {
@@ -36,21 +37,18 @@ pub extern "C" fn await_finish(id: u32, timeout: i64) {
             });
     }
     match unsafe { KERNEL_CHANNEL_0TO1.as_mut().unwrap() }.recv() {
-        Message::SubkernelAwaitFinishReply {
-            status: SubkernelStatus::NoError,
-        } => (),
-        Message::SubkernelAwaitFinishReply {
-            status: SubkernelStatus::IncorrectState,
-        } => artiq_raise!("SubkernelError", "Subkernel not running"),
-        Message::SubkernelAwaitFinishReply {
-            status: SubkernelStatus::Timeout,
-        } => artiq_raise!("SubkernelError", "Subkernel timed out"),
-        Message::SubkernelAwaitFinishReply {
-            status: SubkernelStatus::CommLost,
-        } => artiq_raise!("SubkernelError", "Lost communication with satellite"),
-        Message::SubkernelAwaitFinishReply {
-            status: SubkernelStatus::OtherError,
-        } => artiq_raise!("SubkernelError", "An error occurred during subkernel operation"),
+        Message::SubkernelAwaitFinishReply => (),
+        Message::SubkernelError(SubkernelStatus::IncorrectState) => {
+            artiq_raise!("SubkernelError", "Subkernel not running")
+        }
+        Message::SubkernelError(SubkernelStatus::Timeout) => artiq_raise!("SubkernelError", "Subkernel timed out"),
+        Message::SubkernelError(SubkernelStatus::CommLost) => {
+            artiq_raise!("SubkernelError", "Lost communication with satellite")
+        }
+        Message::SubkernelError(SubkernelStatus::OtherError) => {
+            artiq_raise!("SubkernelError", "An error occurred during subkernel operation")
+        }
+        Message::SubkernelError(SubkernelStatus::Exception(raw_exception)) => eh_artiq::raise_raw(&raw_exception),
         _ => panic!("expected SubkernelAwaitFinishReply after SubkernelAwaitFinishRequest"),
     }
 }
@@ -92,30 +90,22 @@ pub extern "C" fn await_message(id: i32, timeout: i64, tags: &CSlice<u8>, min: u
             });
     }
     match unsafe { KERNEL_CHANNEL_0TO1.as_mut().unwrap() }.recv() {
-        Message::SubkernelMsgRecvReply {
-            status: SubkernelStatus::NoError,
-            count,
-        } => {
+        Message::SubkernelMsgRecvReply { count } => {
             if min > count || count > max {
                 artiq_raise!("SubkernelError", "Received more or less arguments than required")
             }
         }
-        Message::SubkernelMsgRecvReply {
-            status: SubkernelStatus::IncorrectState,
-            ..
-        } => artiq_raise!("SubkernelError", "Subkernel not running"),
-        Message::SubkernelMsgRecvReply {
-            status: SubkernelStatus::Timeout,
-            ..
-        } => artiq_raise!("SubkernelError", "Subkernel timed out"),
-        Message::SubkernelMsgRecvReply {
-            status: SubkernelStatus::CommLost,
-            ..
-        } => artiq_raise!("SubkernelError", "Lost communication with satellite"),
-        Message::SubkernelMsgRecvReply {
-            status: SubkernelStatus::OtherError,
-            ..
-        } => artiq_raise!("SubkernelError", "An error occurred during subkernel operation"),
+        Message::SubkernelError(SubkernelStatus::IncorrectState) => {
+            artiq_raise!("SubkernelError", "Subkernel not running")
+        }
+        Message::SubkernelError(SubkernelStatus::Timeout) => artiq_raise!("SubkernelError", "Subkernel timed out"),
+        Message::SubkernelError(SubkernelStatus::CommLost) => {
+            artiq_raise!("SubkernelError", "Lost communication with satellite")
+        }
+        Message::SubkernelError(SubkernelStatus::OtherError) => {
+            artiq_raise!("SubkernelError", "An error occurred during subkernel operation")
+        }
+        Message::SubkernelError(SubkernelStatus::Exception(raw_exception)) => eh_artiq::raise_raw(&raw_exception),
         _ => panic!("expected SubkernelMsgRecvReply after SubkernelMsgRecvRequest"),
     }
     // RpcRecvRequest should be called after this to receive message data

src/runtime/src/comms.rs

@@ -405,8 +405,9 @@ async fn handle_run_kernel(
                 id,
                 destination: _,
                 run,
+                timestamp,
             } => {
-                let succeeded = match subkernel::load(aux_mutex, routing_table, timer, id, run).await {
+                let succeeded = match subkernel::load(aux_mutex, routing_table, timer, id, run, timestamp).await {
                     Ok(()) => true,
                     Err(e) => {
                         error!("Error loading subkernel: {:?}", e);
@@ -422,33 +423,23 @@ async fn handle_run_kernel(
             #[cfg(has_drtio)]
             kernel::Message::SubkernelAwaitFinishRequest { id, timeout } => {
                 let res = subkernel::await_finish(aux_mutex, routing_table, timer, id, timeout).await;
-                let status = match res {
-                    Ok(ref res) => {
+                let response = match res {
+                    Ok(res) => {
                         if res.status == subkernel::FinishStatus::CommLost {
-                            kernel::SubkernelStatus::CommLost
-                        } else if let Some(exception) = &res.exception {
-                            error!("Exception in subkernel");
-                            match stream {
-                                None => (),
-                                Some(stream) => {
-                                    write_chunk(stream, exception).await?;
-                                }
-                            }
-                            // will not be called after exception is served
-                            kernel::SubkernelStatus::OtherError
+                            kernel::Message::SubkernelError(kernel::SubkernelStatus::CommLost)
+                        } else if let Some(exception) = res.exception {
+                            kernel::Message::SubkernelError(kernel::SubkernelStatus::Exception(exception))
                         } else {
-                            kernel::SubkernelStatus::NoError
+                            kernel::Message::SubkernelAwaitFinishReply
                         }
                     }
-                    Err(SubkernelError::Timeout) => kernel::SubkernelStatus::Timeout,
-                    Err(SubkernelError::IncorrectState) => kernel::SubkernelStatus::IncorrectState,
-                    Err(_) => kernel::SubkernelStatus::OtherError,
+                    Err(SubkernelError::Timeout) => kernel::Message::SubkernelError(kernel::SubkernelStatus::Timeout),
+                    Err(SubkernelError::IncorrectState) => {
+                        kernel::Message::SubkernelError(kernel::SubkernelStatus::IncorrectState)
+                    }
+                    Err(_) => kernel::Message::SubkernelError(kernel::SubkernelStatus::OtherError),
                 };
-                control
-                    .borrow_mut()
-                    .tx
-                    .async_send(kernel::Message::SubkernelAwaitFinishReply { status: status })
-                    .await;
+                control.borrow_mut().tx.async_send(response).await;
             }
             #[cfg(has_drtio)]
             kernel::Message::SubkernelMsgSend { id, destination, data } => {
@@ -469,35 +460,23 @@ async fn handle_run_kernel(
             #[cfg(has_drtio)]
             kernel::Message::SubkernelMsgRecvRequest { id, timeout, tags } => {
                 let message_received = subkernel::message_await(id as u32, timeout, timer).await;
-                let (status, count) = match message_received {
-                    Ok(ref message) => (kernel::SubkernelStatus::NoError, message.count),
-                    Err(SubkernelError::Timeout) => (kernel::SubkernelStatus::Timeout, 0),
-                    Err(SubkernelError::IncorrectState) => (kernel::SubkernelStatus::IncorrectState, 0),
-                    Err(SubkernelError::CommLost) => (kernel::SubkernelStatus::CommLost, 0),
+                let response = match message_received {
+                    Ok(ref message) => kernel::Message::SubkernelMsgRecvReply { count: message.count },
+                    Err(SubkernelError::Timeout) => kernel::Message::SubkernelError(kernel::SubkernelStatus::Timeout),
+                    Err(SubkernelError::IncorrectState) => {
+                        kernel::Message::SubkernelError(kernel::SubkernelStatus::IncorrectState)
+                    }
+                    Err(SubkernelError::CommLost) => kernel::Message::SubkernelError(kernel::SubkernelStatus::CommLost),
                     Err(SubkernelError::SubkernelException) => {
-                        error!("Exception in subkernel");
                         // just retrieve the exception
                         let status = subkernel::await_finish(aux_mutex, routing_table, timer, id as u32, timeout)
                             .await
                             .unwrap();
-                        match stream {
-                            None => (),
-                            Some(stream) => {
-                                write_chunk(stream, &status.exception.unwrap()).await?;
-                            }
-                        }
-                        (kernel::SubkernelStatus::OtherError, 0)
+                        kernel::Message::SubkernelError(kernel::SubkernelStatus::Exception(status.exception.unwrap()))
                     }
-                    Err(_) => (kernel::SubkernelStatus::OtherError, 0),
+                    Err(_) => kernel::Message::SubkernelError(kernel::SubkernelStatus::OtherError),
                 };
-                control
-                    .borrow_mut()
-                    .tx
-                    .async_send(kernel::Message::SubkernelMsgRecvReply {
-                        status: status,
-                        count: count,
-                    })
-                    .await;
+                control.borrow_mut().tx.async_send(response).await;
                 if let Ok(message) = message_received {
                     // receive code almost identical to RPC recv, except we are not reading from a stream
                     let mut reader = Cursor::new(message.data);
@@ -529,7 +508,7 @@ async fn handle_run_kernel(
                             .async_send(kernel::Message::RpcRecvReply(Ok(0)))
                             .await;
                         i += 1;
-                        if i < count {
+                        if i < message.count {
                             current_tags = remaining_tags;
                         } else {
                             break;
@@ -718,6 +697,27 @@ async fn handle_connection(
     }
 }
 
+async fn load_and_run_idle_kernel(
+    buffer: &Vec<u8>,
+    control: &Rc<RefCell<kernel::Control>>,
+    up_destinations: &Rc<RefCell<[bool; drtio_routing::DEST_COUNT]>>,
+    aux_mutex: &Rc<Mutex<bool>>,
+    routing_table: &drtio_routing::RoutingTable,
+    timer: GlobalTimer,
+) {
+    info!("Loading idle kernel");
+    let res = handle_flash_kernel(buffer, control, up_destinations, aux_mutex, routing_table, timer).await;
+    match res {
+        Err(_) => warn!("error loading idle kernel"),
+        _ => (),
+    }
+    info!("Running idle kernel");
+    let _ = handle_run_kernel(None, control, up_destinations, aux_mutex, routing_table, timer)
+        .await
+        .map_err(|_| warn!("error running idle kernel"));
+    info!("Idle kernel terminated");
+}
+
 pub fn main(timer: GlobalTimer, cfg: Config) {
     let net_addresses = net_settings::get_addresses(&cfg);
     info!("network addresses: {}", net_addresses);
@@ -771,7 +771,7 @@ pub fn main(timer: GlobalTimer, cfg: Config) {
     #[cfg(has_drtio_routing)]
     drtio_routing::interconnect_disable_all();
 
-    rtio_mgt::startup(&aux_mutex, &drtio_routing_table, &up_destinations, timer);
+    rtio_mgt::startup(&aux_mutex, &drtio_routing_table, &up_destinations, &cfg, timer);
     ksupport::setup_device_map(&cfg);
 
     analyzer::start(&aux_mutex, &drtio_routing_table, &up_destinations, timer);
@@ -808,8 +808,30 @@ pub fn main(timer: GlobalTimer, cfg: Config) {
     mgmt::start(cfg);
 
     task::spawn(async move {
-        let connection = Rc::new(Semaphore::new(1, 1));
+        let connection = Rc::new(Semaphore::new(0, 1));
         let terminate = Rc::new(Semaphore::new(0, 1));
+        {
+            let control = control.clone();
+            let idle_kernel = idle_kernel.clone();
+            let connection = connection.clone();
+            let terminate = terminate.clone();
+            let up_destinations = up_destinations.clone();
+            let aux_mutex = aux_mutex.clone();
+            let routing_table = drtio_routing_table.clone();
+            task::spawn(async move {
+                let routing_table = routing_table.borrow();
+                select_biased! {
+                    _ = (async {
+                        if let Some(buffer) = &*idle_kernel {
+                            load_and_run_idle_kernel(&buffer, &control, &up_destinations, &aux_mutex, &routing_table, timer).await;
+                        }
+                    }).fuse() => (),
+                    _ = terminate.async_wait().fuse() => ()
+                }
+                connection.signal();
+            });
+        }
+
         loop {
             let mut stream = TcpStream::accept(1381, 0x10_000, 0x10_000).await.unwrap();
 
@@ -837,22 +859,7 @@ pub fn main(timer: GlobalTimer, cfg: Config) {
                             .await
                             .map_err(|e| warn!("connection terminated: {}", e));
                         if let Some(buffer) = &*idle_kernel {
-                            info!("Loading idle kernel");
-                            let res = handle_flash_kernel(&buffer, &control, &up_destinations,  &aux_mutex, &routing_table, timer)
-                                .await;
-                            match res {
-                                #[cfg(has_drtio)]
-                                Err(Error::DestinationDown) => {
-                                    let mut countdown = timer.countdown();
-                                    delay(&mut countdown, Milliseconds(500)).await;
-                                }
-                                Err(_) => warn!("error loading idle kernel"),
-                                _ => (),
-                            }
-                            info!("Running idle kernel");
-                            let _ = handle_run_kernel(None, &control, &up_destinations, &aux_mutex, &routing_table, timer)
-                                .await.map_err(|_| warn!("error running idle kernel"));
-                            info!("Idle kernel terminated");
+                            load_and_run_idle_kernel(&buffer, &control, &up_destinations, &aux_mutex, &routing_table, timer).await;
                         }
                     }).fuse() => (),
                     _ = terminate.async_wait().fuse() => ()

src/runtime/src/moninj.rs

@@ -102,7 +102,7 @@ mod remote_moninj {
         overrd: i8,
         value: i8,
     ) {
-        let _lock = aux_mutex.lock();
+        let _lock = aux_mutex.async_lock().await;
         drtioaux_async::send(
             linkno,
             &drtioaux_async::Packet::InjectionRequest {

src/runtime/src/rtio_mgt.rs

@@ -3,7 +3,9 @@ use core::cell::RefCell;
 
 use libboard_artiq::{drtio_routing, drtio_routing::RoutingTable, pl::csr};
 use libboard_zynq::timer::GlobalTimer;
+use libconfig::Config;
 use libcortex_a9::mutex::Mutex;
+use log::{info, warn};
 
 #[cfg(has_drtio)]
 pub mod drtio {
@@ -127,6 +129,8 @@ pub mod drtio {
             | Packet::SubkernelLoadRunReply { destination, .. }
             | Packet::SubkernelMessage { destination, .. }
             | Packet::SubkernelMessageAck { destination, .. }
+            | Packet::SubkernelException { destination, .. }
+            | Packet::SubkernelExceptionRequest { destination, .. }
             | Packet::DmaPlaybackStatus { destination, .. }
             | Packet::SubkernelFinished { destination, .. } => {
                 if destination == 0 {
@@ -181,10 +185,7 @@ pub mod drtio {
 
     async fn drain_buffer(linkno: u8, draining_time: Milliseconds, timer: GlobalTimer) {
         let max_time = timer.get_time() + draining_time;
-        loop {
-            if timer.get_time() > max_time {
-                return;
-            }
+        while timer.get_time() < max_time {
             let _ = drtioaux_async::recv(linkno).await;
         }
     }
@@ -791,6 +792,7 @@ pub mod drtio {
         id: u32,
         destination: u8,
         run: bool,
+        timestamp: u64,
     ) -> Result<(), Error> {
         let linkno = routing_table.0[destination as usize][0] - 1;
         let reply = aux_transact(
@@ -802,6 +804,7 @@ pub mod drtio {
                 source: 0,
                 destination: destination,
                 run: run,
+                timestamp,
             },
             timer,
         )
@@ -833,13 +836,19 @@ pub mod drtio {
                 linkno,
                 routing_table,
                 &Packet::SubkernelExceptionRequest {
+                    source: 0,
                     destination: destination,
                 },
                 timer,
             )
             .await?;
             match reply {
-                Packet::SubkernelException { last, length, data } => {
+                Packet::SubkernelException {
+                    destination: 0,
+                    last,
+                    length,
+                    data,
+                } => {
                     remote_data.extend(&data[0..length as usize]);
                     if last {
                         return Ok(remote_data);
@@ -898,12 +907,36 @@ pub mod drtio {
     pub fn reset(_aux_mutex: Rc<Mutex<bool>>, _routing_table: &RoutingTable, mut _timer: GlobalTimer) {}
 }
 
+fn toggle_sed_spread(val: u8) {
+    unsafe {
+        csr::rtio_core::sed_spread_enable_write(val);
+    }
+}
+
+fn setup_sed_spread(cfg: &Config) {
+    if let Ok(spread_enable) = cfg.read_str("sed_spread_enable") {
+        match spread_enable.as_ref() {
+            "1" => toggle_sed_spread(1),
+            "0" => toggle_sed_spread(0),
+            _ => {
+                warn!("sed_spread_enable value not supported (only 1, 0 allowed), disabling by default");
+                toggle_sed_spread(0)
+            }
+        };
+    } else {
+        info!("SED spreading disabled by default");
+        toggle_sed_spread(0);
+    }
+}
+
 pub fn startup(
     aux_mutex: &Rc<Mutex<bool>>,
     routing_table: &Rc<RefCell<RoutingTable>>,
     up_destinations: &Rc<RefCell<[bool; drtio_routing::DEST_COUNT]>>,
+    cfg: &Config,
     timer: GlobalTimer,
 ) {
+    setup_sed_spread(cfg);
     drtio::startup(aux_mutex, routing_table, up_destinations, timer);
     unsafe {
         csr::rtio_core::reset_phy_write(1);

src/runtime/src/subkernel.rs

@@ -100,12 +100,22 @@ pub async fn load(
     timer: GlobalTimer,
     id: u32,
     run: bool,
+    timestamp: u64,
 ) -> Result<(), Error> {
     if let Some(subkernel) = SUBKERNELS.async_lock().await.get_mut(&id) {
         if subkernel.state != SubkernelState::Uploaded {
             return Err(Error::IncorrectState);
         }
-        drtio::subkernel_load(aux_mutex, routing_table, timer, id, subkernel.destination, run).await?;
+        drtio::subkernel_load(
+            aux_mutex,
+            routing_table,
+            timer,
+            id,
+            subkernel.destination,
+            run,
+            timestamp,
+        )
+        .await?;
         if run {
             subkernel.state = SubkernelState::Running;
         }

src/satman/src/main.rs

@@ -12,6 +12,7 @@ extern crate io;
 extern crate ksupport;
 extern crate libboard_artiq;
 extern crate libboard_zynq;
+extern crate libconfig;
 extern crate libcortex_a9;
 extern crate libregister;
 extern crate libsupport_zynq;
@@ -38,6 +39,7 @@ use libboard_artiq::{drtio_routing, drtioaux,
 #[cfg(feature = "target_kasli_soc")]
 use libboard_zynq::error_led::ErrorLED;
 use libboard_zynq::{i2c::I2c, print, println, time::Milliseconds, timer::GlobalTimer};
+use libconfig::Config;
 use libcortex_a9::{l2c::enable_l2_cache, regs::MPIDR};
 use libregister::RegisterR;
 use libsupport_zynq::{exception_vectors, ram};
@@ -81,15 +83,37 @@ fn drtiosat_tsc_loaded() -> bool {
     }
 }
 
+fn toggle_sed_spread(val: u8) {
+    unsafe {
+        csr::drtiosat::sed_spread_enable_write(val);
+    }
+}
+
 #[cfg(has_drtio_routing)]
 macro_rules! forward {
-    ($routing_table:expr, $destination:expr, $rank:expr, $repeaters:expr, $packet:expr, $timer:expr) => {{
+    (
+        $router:expr,
+        $routing_table:expr,
+        $destination:expr,
+        $rank:expr,
+        $self_destination:expr,
+        $repeaters:expr,
+        $packet:expr,
+        $timer:expr
+    ) => {{
         let hop = $routing_table.0[$destination as usize][$rank as usize];
         if hop != 0 {
             let repno = (hop - 1) as usize;
             if repno < $repeaters.len() {
                 if $packet.expects_response() {
-                    return $repeaters[repno].aux_forward($packet, $timer);
+                    return $repeaters[repno].aux_forward(
+                        $packet,
+                        $router,
+                        $routing_table,
+                        $rank,
+                        $self_destination,
+                        $timer,
+                    );
                 } else {
                     return $repeaters[repno].aux_send($packet);
                 }
@@ -102,7 +126,16 @@ macro_rules! forward {
 
 #[cfg(not(has_drtio_routing))]
 macro_rules! forward {
-    ($routing_table:expr, $destination:expr, $rank:expr, $repeaters:expr, $packet:expr, $timer:expr) => {};
+    (
+        $router:expr,
+        $routing_table:expr,
+        $destination:expr,
+        $rank:expr,
+        $self_destination:expr,
+        $repeaters:expr,
+        $packet:expr,
+        $timer:expr
+    ) => {};
 }
 
 fn process_aux_packet(
@@ -183,6 +216,10 @@ fn process_aux_packet(
                             &drtioaux::Packet::DestinationStatusRequest {
                                 destination: destination,
                             },
+                            router,
+                            _routing_table,
+                            *rank,
+                            *self_destination,
                             timer,
                         ) {
                             Ok(()) => (),
@@ -244,7 +281,16 @@ fn process_aux_packet(
             channel,
             probe,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             let value;
             #[cfg(has_rtio_moninj)]
             unsafe {
@@ -266,7 +312,16 @@ fn process_aux_packet(
             overrd,
             value,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             #[cfg(has_rtio_moninj)]
             unsafe {
                 csr::rtio_moninj::inj_chan_sel_write(channel as _);
@@ -280,7 +335,16 @@ fn process_aux_packet(
             channel,
             overrd,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             let value;
             #[cfg(has_rtio_moninj)]
             unsafe {
@@ -299,7 +363,16 @@ fn process_aux_packet(
             destination: _destination,
             busno: _busno,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             let succeeded = i2c.start().is_ok();
             drtioaux::send(0, &drtioaux::Packet::I2cBasicReply { succeeded: succeeded })
         }
@@ -307,7 +380,16 @@ fn process_aux_packet(
             destination: _destination,
             busno: _busno,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             let succeeded = i2c.restart().is_ok();
             drtioaux::send(0, &drtioaux::Packet::I2cBasicReply { succeeded: succeeded })
         }
@@ -315,7 +397,16 @@ fn process_aux_packet(
             destination: _destination,
             busno: _busno,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             let succeeded = i2c.stop().is_ok();
             drtioaux::send(0, &drtioaux::Packet::I2cBasicReply { succeeded: succeeded })
         }
@@ -324,7 +415,16 @@ fn process_aux_packet(
             busno: _busno,
             data,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             match i2c.write(data) {
                 Ok(ack) => drtioaux::send(
                     0,
@@ -347,7 +447,16 @@ fn process_aux_packet(
             busno: _busno,
             ack,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             match i2c.read(ack) {
                 Ok(data) => drtioaux::send(
                     0,
@@ -371,7 +480,16 @@ fn process_aux_packet(
             address,
             mask,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             let ch = match mask {
                 //decode from mainline, PCA9548-centric API
                 0x00 => None,
@@ -397,7 +515,16 @@ fn process_aux_packet(
             div: _div,
             cs: _cs,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             // todo: reimplement when/if SPI is available
             //let succeeded = spi::set_config(busno, flags, length, div, cs).is_ok();
             drtioaux::send(0, &drtioaux::Packet::SpiBasicReply { succeeded: false })
@@ -407,7 +534,16 @@ fn process_aux_packet(
             busno: _busno,
             data: _data,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             // todo: reimplement when/if SPI is available
             //let succeeded = spi::write(busno, data).is_ok();
             drtioaux::send(0, &drtioaux::Packet::SpiBasicReply { succeeded: false })
@@ -416,7 +552,16 @@ fn process_aux_packet(
             destination: _destination,
             busno: _busno,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             // todo: reimplement when/if SPI is available
             // match spi::read(busno) {
             //     Ok(data) => drtioaux::send(0,
@@ -436,7 +581,16 @@ fn process_aux_packet(
         drtioaux::Packet::AnalyzerHeaderRequest {
             destination: _destination,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             let header = analyzer.get_header();
             drtioaux::send(
                 0,
@@ -450,7 +604,16 @@ fn process_aux_packet(
         drtioaux::Packet::AnalyzerDataRequest {
             destination: _destination,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             let mut data_slice: [u8; SAT_PAYLOAD_MAX_SIZE] = [0; SAT_PAYLOAD_MAX_SIZE];
             let meta = analyzer.get_data(&mut data_slice);
             drtioaux::send(
@@ -471,7 +634,16 @@ fn process_aux_packet(
             length,
             trace,
         } => {
-            forward!(_routing_table, destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             *self_destination = destination;
             let succeeded = dma_manager.add(source, id, status, &trace, length as usize).is_ok();
             router.send(
@@ -492,7 +664,16 @@ fn process_aux_packet(
             id,
             succeeded,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             dma_manager.ack_upload(
                 kernel_manager,
                 source,
@@ -510,7 +691,16 @@ fn process_aux_packet(
             destination: _destination,
             id,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             let succeeded = dma_manager.erase(source, id).is_ok();
             router.send(
                 drtioaux::Packet::DmaRemoveTraceReply {
@@ -526,7 +716,16 @@ fn process_aux_packet(
             destination: _destination,
             succeeded: _,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             Ok(())
         }
         drtioaux::Packet::DmaPlaybackRequest {
@@ -535,7 +734,16 @@ fn process_aux_packet(
             id,
             timestamp,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             let succeeded = if !kernel_manager.running() {
                 dma_manager.playback(source, id, timestamp).is_ok()
             } else {
@@ -555,7 +763,16 @@ fn process_aux_packet(
             destination: _destination,
             succeeded,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             if !succeeded {
                 kernel_manager.ddma_nack();
             }
@@ -569,7 +786,16 @@ fn process_aux_packet(
             channel,
             timestamp,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             dma_manager.remote_finished(kernel_manager, id, error, channel, timestamp);
             Ok(())
         }
@@ -581,7 +807,16 @@ fn process_aux_packet(
             length,
             data,
         } => {
-            forward!(_routing_table, destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             *self_destination = destination;
             let succeeded = kernel_manager.add(id, status, &data, length as usize).is_ok();
             drtioaux::send(0, &drtioaux::Packet::SubkernelAddDataReply { succeeded: succeeded })
@@ -591,8 +826,18 @@ fn process_aux_packet(
             destination: _destination,
             id,
             run,
+            timestamp,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             let mut succeeded = kernel_manager.load(id).is_ok();
             // allow preloading a kernel with delayed run
             if run {
@@ -600,7 +845,7 @@ fn process_aux_packet(
                     // cannot run kernel while DDMA is running
                     succeeded = false;
                 } else {
-                    succeeded |= kernel_manager.run(source, id).is_ok();
+                    succeeded |= kernel_manager.run(source, id, timestamp).is_ok();
                 }
             }
             router.send(
@@ -617,7 +862,16 @@ fn process_aux_packet(
             destination: _destination,
             succeeded,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             // received if local subkernel started another, remote subkernel
             kernel_manager.subkernel_load_run_reply(succeeded);
             Ok(())
@@ -628,25 +882,73 @@ fn process_aux_packet(
             with_exception,
             exception_src,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             kernel_manager.remote_subkernel_finished(id, with_exception, exception_src);
             Ok(())
         }
         drtioaux::Packet::SubkernelExceptionRequest {
+            source,
             destination: _destination,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
-            let mut data_slice: [u8; SAT_PAYLOAD_MAX_SIZE] = [0; SAT_PAYLOAD_MAX_SIZE];
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
+            let mut data_slice: [u8; MASTER_PAYLOAD_MAX_SIZE] = [0; MASTER_PAYLOAD_MAX_SIZE];
             let meta = kernel_manager.exception_get_slice(&mut data_slice);
-            drtioaux::send(
-                0,
-                &drtioaux::Packet::SubkernelException {
+            router.send(
+                drtioaux::Packet::SubkernelException {
+                    destination: source,
                     last: meta.status.is_last(),
                     length: meta.len,
                     data: data_slice,
                 },
+                _routing_table,
+                *rank,
+                *self_destination,
             )
         }
+        drtioaux::Packet::SubkernelException {
+            destination: _destination,
+            last,
+            length,
+            data,
+        } => {
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
+            kernel_manager.received_exception(
+                &data[..length as usize],
+                last,
+                router,
+                _routing_table,
+                *rank,
+                *self_destination,
+            );
+            Ok(())
+        }
         drtioaux::Packet::SubkernelMessage {
             source,
             destination: _destination,
@@ -655,7 +957,16 @@ fn process_aux_packet(
             length,
             data,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             kernel_manager.message_handle_incoming(status, id, length as usize, &data);
             router.send(
                 drtioaux::Packet::SubkernelMessageAck { destination: source },
@@ -667,7 +978,16 @@ fn process_aux_packet(
         drtioaux::Packet::SubkernelMessageAck {
             destination: _destination,
         } => {
-            forward!(_routing_table, _destination, *rank, _repeaters, &packet, timer);
+            forward!(
+                router,
+                _routing_table,
+                _destination,
+                *rank,
+                *self_destination,
+                _repeaters,
+                &packet,
+                timer
+            );
             if kernel_manager.message_ack_slice() {
                 let mut data_slice: [u8; MASTER_PAYLOAD_MAX_SIZE] = [0; MASTER_PAYLOAD_MAX_SIZE];
                 if let Some(meta) = kernel_manager.message_get_slice(&mut data_slice) {
@@ -920,6 +1240,28 @@ pub extern "C" fn main_core0() -> i32 {
     #[cfg(has_si549)]
     si549::helper_setup(&mut timer, &SI549_SETTINGS).expect("cannot initialize helper Si549");
 
+    let cfg = match Config::new() {
+        Ok(cfg) => cfg,
+        Err(err) => {
+            warn!("config initialization failed: {}", err);
+            Config::new_dummy()
+        }
+    };
+
+    if let Ok(spread_enable) = cfg.read_str("sed_spread_enable") {
+        match spread_enable.as_ref() {
+            "1" => toggle_sed_spread(1),
+            "0" => toggle_sed_spread(0),
+            _ => {
+                warn!("sed_spread_enable value not supported (only 1, 0 allowed), disabling by default");
+                toggle_sed_spread(0)
+            }
+        };
+    } else {
+        info!("SED spreading disabled by default");
+        toggle_sed_spread(0);
+    }
+
     #[cfg(has_drtio_routing)]
     let mut repeaters = [repeater::Repeater::default(); csr::DRTIOREP.len()];
     #[cfg(not(has_drtio_routing))]

src/satman/src/repeater.rs

@@ -87,6 +87,10 @@ impl Repeater {
                 if rep_link_rx_up(self.repno) {
                     if let Ok(Some(drtioaux::Packet::EchoReply)) = drtioaux::recv(self.auxno) {
                         info!("[REP#{}] remote replied after {} packets", self.repno, ping_count);
+                        let max_time = timer.get_time() + Milliseconds(200);
+                        while timer.get_time() < max_time {
+                            let _ = drtioaux::recv(self.auxno);
+                        }
                         self.state = RepeaterState::Up;
                         if let Err(e) = self.sync_tsc(timer) {
                             error!("[REP#{}] failed to sync TSC ({:?})", self.repno, e);
@@ -204,10 +208,37 @@ impl Repeater {
         }
     }
 
-    pub fn aux_forward(&self, request: &drtioaux::Packet, timer: &mut GlobalTimer) -> Result<(), drtioaux::Error> {
+    pub fn aux_forward(
+        &self,
+        request: &drtioaux::Packet,
+        router: &mut Router,
+        routing_table: &drtio_routing::RoutingTable,
+        rank: u8,
+        self_destination: u8,
+        timer: &mut GlobalTimer,
+    ) -> Result<(), drtioaux::Error> {
         self.aux_send(request)?;
-        let reply = self.recv_aux_timeout(200, timer)?;
-        drtioaux::send(0, &reply).unwrap();
+        loop {
+            let reply = self.recv_aux_timeout(200, timer)?;
+            match reply {
+                // async/locally requested packets to be consumed or routed
+                // these may come while a packet would be forwarded
+                drtioaux::Packet::DmaPlaybackStatus { .. }
+                | drtioaux::Packet::SubkernelFinished { .. }
+                | drtioaux::Packet::SubkernelMessage { .. }
+                | drtioaux::Packet::SubkernelMessageAck { .. }
+                | drtioaux::Packet::SubkernelLoadRunReply { .. }
+                | drtioaux::Packet::SubkernelException { .. }
+                | drtioaux::Packet::DmaAddTraceReply { .. }
+                | drtioaux::Packet::DmaPlaybackReply { .. } => {
+                    router.route(reply, routing_table, rank, self_destination);
+                }
+                _ => {
+                    drtioaux::send(0, &reply).unwrap();
+                    break;
+                }
+            }
+        }
         Ok(())
     }
 

src/satman/src/routing.rs

@@ -4,7 +4,7 @@ use core::cmp::min;
 #[cfg(has_drtio_routing)]
 use libboard_artiq::pl::csr;
 use libboard_artiq::{drtio_routing, drtioaux,
-                     drtioaux_proto::{PayloadStatus, MASTER_PAYLOAD_MAX_SIZE, SAT_PAYLOAD_MAX_SIZE}};
+                     drtioaux_proto::{PayloadStatus, MASTER_PAYLOAD_MAX_SIZE}};
 
 pub struct SliceMeta {
     pub destination: u8,
@@ -57,7 +57,6 @@ impl Sliceable {
         self.data.extend(data);
     }
 
-    get_slice_fn!(get_slice_sat, SAT_PAYLOAD_MAX_SIZE);
     get_slice_fn!(get_slice_master, MASTER_PAYLOAD_MAX_SIZE);
 }
 

src/satman/src/subkernel.rs

@@ -8,10 +8,10 @@ use core_io::{Error as IoError, Write};
 use cslice::AsCSlice;
 use dma::{Error as DmaError, Manager as DmaManager};
 use io::{Cursor, ProtoWrite};
-use ksupport::{eh_artiq, kernel, rpc};
+use ksupport::{eh_artiq, kernel, rpc, rtio};
 use libboard_artiq::{drtio_routing::RoutingTable,
                      drtioaux,
-                     drtioaux_proto::{PayloadStatus, MASTER_PAYLOAD_MAX_SIZE, SAT_PAYLOAD_MAX_SIZE},
+                     drtioaux_proto::{PayloadStatus, MASTER_PAYLOAD_MAX_SIZE},
                      pl::csr};
 use libboard_zynq::{time::Milliseconds, timer::GlobalTimer};
 use libcortex_a9::sync_channel::Receiver;
@@ -47,6 +47,9 @@ enum KernelState {
     DmaAwait {
         max_time: Milliseconds,
     },
+    SubkernelRetrievingException {
+        destination: u8,
+    },
 }
 
 #[derive(Debug)]
@@ -123,10 +126,11 @@ struct MessageManager {
 struct Session {
     id: u32,
     kernel_state: KernelState,
-    last_exception: Option<Sliceable>,
+    last_exception: Option<Sliceable>,   // exceptions raised locally
+    external_exception: Option<Vec<u8>>, // exceptions from sub-subkernels
     messages: MessageManager,
     source: u8, // which destination requested running the kernel
-    subkernels_finished: Vec<u32>,
+    subkernels_finished: Vec<(u32, Option<u8>)>,
 }
 
 impl Session {
@@ -135,6 +139,7 @@ impl Session {
             id: id,
             kernel_state: KernelState::Absent,
             last_exception: None,
+            external_exception: None,
             messages: MessageManager::new(),
             source: 0,
             subkernels_finished: Vec::new(),
@@ -344,7 +349,7 @@ impl<'a> Manager<'_> {
         }
     }
 
-    pub fn run(&mut self, source: u8, id: u32) -> Result<(), Error> {
+    pub fn run(&mut self, source: u8, id: u32, timestamp: u64) -> Result<(), Error> {
         if self.session.kernel_state != KernelState::Loaded || self.session.id != id {
             self.load(id)?;
         }
@@ -354,6 +359,7 @@ impl<'a> Manager<'_> {
             csr::cri_con::selected_write(2);
         }
 
+        rtio::at_mu(timestamp as i64);
         self.control.tx.send(kernel::Message::StartRequest);
         Ok(())
     }
@@ -410,9 +416,9 @@ impl<'a> Manager<'_> {
         }
     }
 
-    pub fn exception_get_slice(&mut self, data_slice: &mut [u8; SAT_PAYLOAD_MAX_SIZE]) -> SliceMeta {
+    pub fn exception_get_slice(&mut self, data_slice: &mut [u8; MASTER_PAYLOAD_MAX_SIZE]) -> SliceMeta {
         match self.session.last_exception.as_mut() {
-            Some(exception) => exception.get_slice_sat(data_slice),
+            Some(exception) => exception.get_slice_master(data_slice),
             None => SliceMeta {
                 destination: 0,
                 len: 0,
@@ -540,7 +546,7 @@ impl<'a> Manager<'_> {
             return;
         }
 
-        match self.process_external_messages(timer) {
+        match self.process_external_messages(router, routing_table, rank, destination, timer) {
             Ok(()) => (),
             Err(Error::AwaitingMessage) => return, // kernel still waiting, do not process kernel messages
             Err(Error::KernelException(exception)) => {
@@ -596,6 +602,41 @@ impl<'a> Manager<'_> {
         }
     }
 
+    fn check_finished_kernels(
+        &mut self,
+        id: u32,
+        router: &mut Router,
+        routing_table: &RoutingTable,
+        rank: u8,
+        self_destination: u8,
+    ) {
+        for (i, (status, exception_source)) in self.session.subkernels_finished.iter().enumerate() {
+            if *status == id {
+                if exception_source.is_none() {
+                    self.control.tx.send(kernel::Message::SubkernelAwaitFinishReply);
+                    self.session.kernel_state = KernelState::Running;
+                    self.session.subkernels_finished.swap_remove(i);
+                } else {
+                    let destination = exception_source.unwrap();
+                    self.session.external_exception = Some(Vec::new());
+                    self.session.kernel_state = KernelState::SubkernelRetrievingException {
+                        destination: destination,
+                    };
+                    router.route(
+                        drtioaux::Packet::SubkernelExceptionRequest {
+                            source: self_destination,
+                            destination: destination,
+                        },
+                        &routing_table,
+                        rank,
+                        self_destination,
+                    );
+                }
+                break;
+            }
+        }
+    }
+
     pub fn subkernel_load_run_reply(&mut self, succeeded: bool) {
         if self.session.kernel_state == KernelState::SubkernelAwaitLoad {
             self.control
@@ -608,16 +649,46 @@ impl<'a> Manager<'_> {
     }
 
     pub fn remote_subkernel_finished(&mut self, id: u32, with_exception: bool, exception_source: u8) {
-        if with_exception {
-            self.kernel_stop();
-            self.last_finished = Some(SubkernelFinished {
-                source: self.session.source,
-                id: self.session.id,
-                with_exception: true,
-                exception_source: exception_source,
-            })
+        let exception_src = if with_exception { Some(exception_source) } else { None };
+        self.session.subkernels_finished.push((id, exception_src));
+    }
+
+    pub fn received_exception(
+        &mut self,
+        exception_data: &[u8],
+        last: bool,
+        router: &mut Router,
+        routing_table: &RoutingTable,
+        rank: u8,
+        self_destination: u8,
+    ) {
+        if let KernelState::SubkernelRetrievingException { destination } = self.session.kernel_state {
+            self.session
+                .external_exception
+                .as_mut()
+                .unwrap()
+                .extend_from_slice(exception_data);
+            if last {
+                self.control
+                    .tx
+                    .send(kernel::Message::SubkernelError(kernel::SubkernelStatus::Exception(
+                        self.session.external_exception.take().unwrap(),
+                    )));
+                self.session.kernel_state = KernelState::Running;
+            } else {
+                /* fetch another slice */
+                router.route(
+                    drtioaux::Packet::SubkernelExceptionRequest {
+                        source: self_destination,
+                        destination: destination,
+                    },
+                    routing_table,
+                    rank,
+                    self_destination,
+                );
+            }
         } else {
-            self.session.subkernels_finished.push(id);
+            warn!("Received unsolicited exception data");
         }
     }
 
@@ -742,6 +813,7 @@ impl<'a> Manager<'_> {
                 id,
                 destination: sk_destination,
                 run,
+                timestamp,
             } => {
                 self.session.kernel_state = KernelState::SubkernelAwaitLoad;
                 router.route(
@@ -750,6 +822,7 @@ impl<'a> Manager<'_> {
                         destination: sk_destination,
                         id: id,
                         run: run,
+                        timestamp,
                     },
                     routing_table,
                     rank,
@@ -780,28 +853,35 @@ impl<'a> Manager<'_> {
         Ok(false)
     }
 
-    fn process_external_messages(&mut self, timer: &GlobalTimer) -> Result<(), Error> {
+    fn process_external_messages(
+        &mut self,
+        router: &mut Router,
+        routing_table: &RoutingTable,
+        rank: u8,
+        self_destination: u8,
+        timer: &GlobalTimer,
+    ) -> Result<(), Error> {
         match &self.session.kernel_state {
             KernelState::MsgAwait { max_time, id, tags } => {
                 if let Some(max_time) = *max_time {
                     if timer.get_time() > max_time {
-                        self.control.tx.send(kernel::Message::SubkernelMsgRecvReply {
-                            status: kernel::SubkernelStatus::Timeout,
-                            count: 0,
-                        });
+                        self.control
+                            .tx
+                            .send(kernel::Message::SubkernelError(kernel::SubkernelStatus::Timeout));
                         self.session.kernel_state = KernelState::Running;
                         return Ok(());
                     }
                 }
                 if let Some(message) = self.session.messages.get_incoming(*id) {
-                    self.control.tx.send(kernel::Message::SubkernelMsgRecvReply {
-                        status: kernel::SubkernelStatus::NoError,
-                        count: message.count,
-                    });
+                    self.control
+                        .tx
+                        .send(kernel::Message::SubkernelMsgRecvReply { count: message.count });
                     let tags = tags.clone();
                     self.session.kernel_state = KernelState::Running;
                     self.pass_message_to_kernel(&message, tags, timer)
                 } else {
+                    let id = *id;
+                    self.check_finished_kernels(id, router, routing_table, rank, self_destination);
                     Err(Error::AwaitingMessage)
                 }
             }
@@ -817,27 +897,18 @@ impl<'a> Manager<'_> {
             KernelState::SubkernelAwaitFinish { max_time, id } => {
                 if let Some(max_time) = *max_time {
                     if timer.get_time() > max_time {
-                        self.control.tx.send(kernel::Message::SubkernelAwaitFinishReply {
-                            status: kernel::SubkernelStatus::Timeout,
-                        });
+                        self.control
+                            .tx
+                            .send(kernel::Message::SubkernelError(kernel::SubkernelStatus::Timeout));
                         self.session.kernel_state = KernelState::Running;
                         return Ok(());
                     }
                 }
-                let mut i = 0;
-                for status in &self.session.subkernels_finished {
-                    if *status == *id {
-                        self.control.tx.send(kernel::Message::SubkernelAwaitFinishReply {
-                            status: kernel::SubkernelStatus::NoError,
-                        });
-                        self.session.kernel_state = KernelState::Running;
-                        self.session.subkernels_finished.swap_remove(i);
-                        break;
-                    }
-                    i += 1;
-                }
+                let id = *id;
+                self.check_finished_kernels(id, router, routing_table, rank, self_destination);
                 Ok(())
             }
+            KernelState::SubkernelRetrievingException { .. } => Err(Error::AwaitingMessage),
             KernelState::DmaAwait { max_time } | KernelState::DmaPendingAwait { max_time, .. } => {
                 if timer.get_time() > *max_time {
                     self.control.tx.send(kernel::Message::DmaAwaitRemoteReply {