Add the EFR32 watchdog to RPC firmware (#33)

* Create a `.gitignore` file

* Add a watchdog Gecko SDK extension

* Trust Gecko SDK extensions when building

* Allow patching the generated project file

* Add watchdog to RCP firmwares

* Ensure `pip` is available

* `yq` is available in Debian, use it directly

* Use correct parameter for `slc signature trust` command

* Ensure extension path is absolute

* Link extensions within the SDK to get slc-cli to actually work

* Revert namespacing for `#define`s hard-coded in the SDK

* [WIP] Simplify extension to bare minimum

* Register watchdog initialization later

* Remove debugging code

* Reset the watchdog timer at 25%

* Pass through `slcp_yaml_changes`

* Feed watchdog timer within the app, not in a timer interrupt handler

* Drop watchdog period to 2 seconds

* Stop running the watchdog when in debugger

.github/workflows/build.yaml

@@ -98,10 +98,16 @@ jobs:
             device: MGM210PA32JIA
             components: simple_led:board_activity,cpc_security_secondary_none,zigbee_mfglib
             patchpath: "RCPMultiPAN/Yellow"
+            slcp_yaml_changes: >
+              . += {"sdk_extension": [{"id": "nc_efr32_watchdog", version: "1.0.0"}]}
+              | .component += [{"from": "nc_efr32_watchdog", "id": "nc_efr32_watchdog"}]
           - target: skyconnect
             device: EFR32MG21A020F512IM32
             components: cpc_security_secondary_none,zigbee_mfglib
             patchpath: "RCPMultiPAN/SkyConnect"
+            slcp_yaml_changes: >
+              . += {"sdk_extension": [{"id": "nc_efr32_watchdog", version: "1.0.0"}]}
+              | .component += [{"from": "nc_efr32_watchdog", "id": "nc_efr32_watchdog"}]
     uses: ./.github/workflows/silabs-firmware-build.yaml
     with:
       image_name: ${{ needs.build-container.outputs.image_name }}
@@ -111,6 +117,7 @@ jobs:
       device: ${{ matrix.device }}
       components: ${{ matrix.components }}
       patchpath: ${{ matrix.patchpath }}
+      slcp_yaml_changes: ${{ matrix.slcp_yaml_changes }}
       sdk_version: ${{ needs.build-container.outputs.sdk_version }}
       metadata_fw_type: "rcp-uart-802154"
       baudrate: 460800

.github/workflows/silabs-firmware-build.yaml

@@ -47,6 +47,9 @@ on:
         required: false
         default: "null"
         type: string
+      slcp_yaml_changes:
+        required: false
+        type: string
 
 jobs:
   firmware-build:
@@ -63,6 +66,19 @@ jobs:
       - name: Adjust permission
         shell: bash
         run: chown builder .
+
+      - name: Link SDK extensions
+        shell: bash
+        run: |
+          # XXX: slc-cli does not actually work when the extensions aren't in the SDK!
+          ln -s $PWD/gecko_sdk_extensions /gecko_sdk/extension
+
+      - name: Trust SDK extensions
+        run: |
+          for ext in /gecko_sdk/extension/*/; do
+            slc signature trust --extension-path="$ext"
+          done
+
       - name: Generate Firmware Project
         run: |
           slc generate \
@@ -110,6 +126,12 @@ jobs:
           sed -i "s/^C_DEFS\s*=.*$/C_DEFS = '-DOPENTHREAD_BUILD_DATETIME=\"$meta_datetime\"' ${{ inputs.extra_c_defs }}/" \
             "${{ inputs.project_name }}.Makefile"
 
+      - name: Patch SLCP project file
+        if: "${{ inputs.slcp_yaml_changes != '' }}"
+        run: |
+          cd ${{ inputs.firmware_name }}
+          yq --in-place --yaml-output '${{ inputs.slcp_yaml_changes }}' "${{ inputs.project_name }}.slcp"
+
       - name: Build Firmware
         run: |
           cd ${{ inputs.firmware_name }}

.gitignore

@@ -0,0 +1 @@
+.DS_Store

Dockerfile

@@ -10,6 +10,7 @@ RUN \
        git \
        git-lfs \
        jq \
+       yq \
        libgl1 \
        make \
        default-jre-headless \

gecko_sdk_extensions/nc_efr32_watchdog_extension/inc/nc_efr32_wdog.h

@@ -0,0 +1,26 @@
+/***************************************************************************//**
+ * @file nc_efr32_wdog.h
+ * @brief Legacy HAL Watchdog
+ *******************************************************************************
+ * # License
+ * <b>Copyright 2022 Silicon Laboratories, Inc, www.silabs.com</b>
+ *******************************************************************************
+ *
+ * The licensor of this software is Silicon Laboratories Inc. Your use of this
+ * software is governed by the terms of Silicon Labs Master Software License
+ * Agreement (MSLA) available at
+ * www.silabs.com/about-us/legal/master-software-license-agreement. This
+ * software is distributed to you in Source Code format and is governed by the
+ * sections of the MSLA applicable to Source Code.
+ *
+ ******************************************************************************/
+
+#include <stdio.h>
+#include "em_cmu.h"
+#include "em_wdog.h"
+#include "em_rmu.h"
+#include "sli_cpc_timer.h"
+#include "sl_component_catalog.h"
+
+void nc_enable_watchdog(void);
+void nc_periodic_timer(sli_cpc_timer_handle_t *handle, void *data);

gecko_sdk_extensions/nc_efr32_watchdog_extension/nc_efr32_watchdog.slcc

@@ -0,0 +1,38 @@
+root_path: ./
+id: nc_efr32_watchdog
+label: EFR32 Watchdog
+package: ext-comp
+category: External Components
+quality: production
+description: >
+  EFR32 Watchdog.
+requires:
+  - name: component_catalog
+  - name: emlib_wdog
+  - name: emlib_wdog
+provides:
+  - name: nc_efr32_watchdog
+
+source:
+  - path: src/nc_efr32_wdog.c
+
+include:
+  - path: inc
+    file_list:
+    - path: nc_efr32_wdog.h
+
+template_contribution:
+  - name: component_catalog
+    value: nc_efr32_watchdog
+  - name: event_handler
+    value:
+      event: service_init
+      include: "nc_efr32_wdog.h"
+      handler: nc_enable_watchdog
+      priority: 9999  # load very very late
+  - name: event_handler
+    value:
+      event: service_process_action
+      include: "nc_efr32_wdog.h"
+      handler: nc_poke_watchdog
+      priority: 9999  # run last

gecko_sdk_extensions/nc_efr32_watchdog_extension/nc_efr32_watchdog.slce

@@ -0,0 +1,8 @@
+id: "nc_efr32_watchdog"
+label: "EFR32 Watchdog"
+version: "1.0.0"
+sdk:
+  id: "gecko_sdk"
+  version: 4.3.2
+component_path:
+  - path: "./"

gecko_sdk_extensions/nc_efr32_watchdog_extension/src/nc_efr32_wdog.c

@@ -0,0 +1,92 @@
+/***************************************************************************//**
+ * @file nc_efr32_wdog.c
+ * @brief Legacy HAL Watchdog
+ *******************************************************************************
+ * # License
+ * <b>Copyright 2022 Silicon Laboratories, Inc, www.silabs.com</b>
+ *******************************************************************************
+ *
+ * The licensor of this software is Silicon Laboratories Inc. Your use of this
+ * software is governed by the terms of Silicon Labs Master Software License
+ * Agreement (MSLA) available at
+ * www.silabs.com/about-us/legal/master-software-license-agreement. This
+ * software is distributed to you in Source Code format and is governed by the
+ * sections of the MSLA applicable to Source Code.
+ *
+ ******************************************************************************/
+
+#include "em_wdog.h"
+#include "nc_efr32_wdog.h"
+
+static bool feed_watchdog_on_warn_interrupt;
+
+
+#if (_SILICON_LABS_32B_SERIES >= 1)
+void WDOG0_IRQHandler(void)
+{
+  uint32_t interrupts;
+
+  interrupts = WDOGn_IntGet(WDOG0);
+  WDOGn_IntClear(WDOG0, interrupts);
+
+  if (feed_watchdog_on_warn_interrupt) {
+    WDOGn_Feed(WDOG0);
+    feed_watchdog_on_warn_interrupt = false;
+  }
+}
+#endif
+
+
+void nc_enable_watchdog(void)
+{
+  // Enable LE interface
+#if !defined(_SILICON_LABS_32B_SERIES_2)
+  CMU_ClockEnable(cmuClock_HFLE, true);
+  CMU_OscillatorEnable(cmuOsc_LFRCO, true, true);
+#endif
+
+#if defined(_SILICON_LABS_32B_SERIES_2) && !defined(_SILICON_LABS_32B_SERIES_2_CONFIG_1)
+  CMU_ClockEnable(cmuClock_WDOG0, true);
+#endif
+
+  // Make sure FULL reset is used on WDOG timeout
+#if defined(_RMU_CTRL_WDOGRMODE_MASK)
+  RMU_ResetControl(rmuResetWdog, rmuResetModeFull);
+#endif
+
+  WDOG_Init_TypeDef init = WDOG_INIT_DEFAULT;
+  init.enable = false;
+  init.debugRun = false;
+  init.perSel = wdogPeriod_64k;  // 2 seconds
+  init.warnSel = wdogWarnTime75pct;
+
+#if defined(_WDOG_CTRL_CLKSEL_MASK)
+  init.clkSel = wdogClkSelLFRCO;
+#else
+  // Series 2 devices select watchdog oscillator with the CMU.
+  CMU_ClockSelectSet(cmuClock_WDOG0, cmuSelect_LFRCO);
+#endif
+
+  WDOGn_Unlock(WDOG0);
+  WDOGn_Init(WDOG0, &init);
+
+  // Enable warning interrupt
+  NVIC_ClearPendingIRQ(WDOG0_IRQn);
+  WDOGn_IntClear(WDOG0, WDOG_IF_WARN);
+  NVIC_EnableIRQ(WDOG0_IRQn);
+  WDOGn_IntEnable(WDOG0, WDOG_IEN_WARN);
+
+  WDOGn_Enable(WDOG0, true);
+  WDOGn_Feed(WDOG0);
+
+  feed_watchdog_on_warn_interrupt = false;
+}
+
+
+void nc_poke_watchdog()
+{
+  CORE_DECLARE_IRQ_STATE;
+  CORE_ENTER_ATOMIC();
+  feed_watchdog_on_warn_interrupt = true;
+  CORE_EXIT_ATOMIC();
+}