nrf: fix internal flash writes

ports/nrf/bluetooth/ble_drv.c

@@ -39,12 +39,16 @@
 
 nrf_nvic_state_t nrf_nvic_state = { 0 };
 
+// Flag indicating progress of internal flash operation.
+sd_flash_operation_status_t sd_flash_operation_status;
+
 __attribute__((aligned(4)))
 static uint8_t m_ble_evt_buf[sizeof(ble_evt_t) + (BLE_GATT_ATT_MTU_DEFAULT)];
 
 void ble_drv_reset() {
     // Linked list items will be gc'd.
     MP_STATE_VM(ble_drv_evt_handler_entries) = NULL;
+    sd_flash_operation_status = SD_FLASH_OPERATION_DONE;
 }
 
 void ble_drv_add_event_handler(ble_drv_evt_handler_t func, void *param) {
@@ -85,22 +89,29 @@ extern void tusb_hal_nrf_power_event (uint32_t event);
 void SD_EVT_IRQHandler(void) {
     uint32_t evt_id;
     while (sd_evt_get(&evt_id) != NRF_ERROR_NOT_FOUND) {
-//        sd_evt_handler(evt_id);
-
         switch (evt_id) {
             // usb power event
-            case NRF_EVT_POWER_USB_DETECTED:
-            case NRF_EVT_POWER_USB_POWER_READY:
-            case NRF_EVT_POWER_USB_REMOVED: {
-                int32_t usbevt = (evt_id == NRF_EVT_POWER_USB_DETECTED   ) ? NRFX_POWER_USB_EVT_DETECTED:
-                                 (evt_id == NRF_EVT_POWER_USB_POWER_READY) ? NRFX_POWER_USB_EVT_READY   :
-                                 (evt_id == NRF_EVT_POWER_USB_REMOVED    ) ? NRFX_POWER_USB_EVT_REMOVED : -1;
-
-                tusb_hal_nrf_power_event(usbevt);
-            }
+        case NRF_EVT_POWER_USB_DETECTED:
+        case NRF_EVT_POWER_USB_POWER_READY:
+        case NRF_EVT_POWER_USB_REMOVED: {
+            int32_t usbevt = (evt_id == NRF_EVT_POWER_USB_DETECTED   ) ? NRFX_POWER_USB_EVT_DETECTED:
+                (evt_id == NRF_EVT_POWER_USB_POWER_READY) ? NRFX_POWER_USB_EVT_READY   :
+                (evt_id == NRF_EVT_POWER_USB_REMOVED    ) ? NRFX_POWER_USB_EVT_REMOVED : -1;
+
+            tusb_hal_nrf_power_event(usbevt);
+        }
             break;
 
-            default: break;
+            // Set flag indicating that a flash operation has finished.
+        case NRF_EVT_FLASH_OPERATION_SUCCESS:
+            sd_flash_operation_status = SD_FLASH_OPERATION_DONE;
+            break;
+        case NRF_EVT_FLASH_OPERATION_ERROR:
+            sd_flash_operation_status = SD_FLASH_OPERATION_ERROR;
+            break;
+
+        default:
+            break;
         }
     }
 

ports/nrf/bluetooth/ble_drv.h

@@ -50,6 +50,15 @@
 
 typedef void (*ble_drv_evt_handler_t)(ble_evt_t*, void*);
 
+typedef enum {
+    SD_FLASH_OPERATION_DONE,
+    SD_FLASH_OPERATION_IN_PROGRESS,
+    SD_FLASH_OPERATION_ERROR,
+} sd_flash_operation_status_t;
+
+// Flag indicating progress of internal flash operation.
+extern sd_flash_operation_status_t sd_flash_operation_status;
+
 typedef struct ble_drv_evt_handler_entry {
     struct ble_drv_evt_handler_entry *next;
     void *param;

ports/nrf/supervisor/internal_flash.c

@@ -38,6 +38,7 @@
 #include "nrf_nvmc.h"
 
 #ifdef BLUETOOTH_SD
+#include "ble_drv.h"
 #include "nrf_sdm.h"
 #endif
 
@@ -71,26 +72,15 @@ uint32_t supervisor_flash_get_block_count(void) {
 }
 
 #ifdef BLUETOOTH_SD
-STATIC bool wait_for_flash_operation(void) {
-    do {
+STATIC void sd_flash_operation_start(void) {
+    sd_flash_operation_status = SD_FLASH_OPERATION_IN_PROGRESS;
+}
+
+STATIC sd_flash_operation_status_t sd_flash_operation_wait_until_done(void) {
+    while (sd_flash_operation_status == SD_FLASH_OPERATION_IN_PROGRESS) {
         sd_app_evt_wait();
-        uint32_t evt_id;
-        uint32_t result = sd_evt_get(&evt_id);
-        if (result == NRF_SUCCESS) {
-            switch (evt_id) {
-            case NRF_EVT_FLASH_OPERATION_SUCCESS:
-                return true;
-
-            case NRF_EVT_FLASH_OPERATION_ERROR:
-                return false;
-
-            default:
-                // Some other event. Wait for a flash event.
-                continue;
-            }
-        }
-        return false;
-    } while (true);
+    }
+    return sd_flash_operation_status;
 }
 #endif
 
@@ -101,27 +91,55 @@ void supervisor_flash_flush(void) {
     if (memcmp(_flash_cache, (void *)_flash_page_addr, FL_PAGE_SZ) != 0) {
 
 #ifdef BLUETOOTH_SD
-    uint8_t sd_en = 0;
-    (void) sd_softdevice_is_enabled(&sd_en);
-
-    if (sd_en) {
-        sd_flash_page_erase(_flash_page_addr / FL_PAGE_SZ);
-        wait_for_flash_operation();    // TODO: handle error return.
-        sd_flash_write((uint32_t *)_flash_page_addr, (uint32_t *)_flash_cache, FL_PAGE_SZ / sizeof(uint32_t));
-        wait_for_flash_operation();
-    } else {
+        uint8_t sd_en = 0;
+        (void) sd_softdevice_is_enabled(&sd_en);
+
+        if (sd_en) {
+            uint32_t err_code;
+            sd_flash_operation_status_t status;
+
+            sd_flash_operation_start();
+            err_code = sd_flash_page_erase(_flash_page_addr / FL_PAGE_SZ);
+            if (err_code != NRF_SUCCESS) {
+                mp_raise_OSError_msg_varg(translate("Flash erase failed to start, err 0x%04x"), err_code);
+            }
+            status = sd_flash_operation_wait_until_done();
+            if (status == SD_FLASH_OPERATION_ERROR) {
+                mp_raise_OSError_msg(translate("Flash erase failed"));
+            }
+
+            // Divide a full page into parts, because writing a full page causes an assertion failure.
+            // See https://devzone.nordicsemi.com/f/nordic-q-a/40088/sd_flash_write-cause-nrf_fault_id_sd_assert/
+            const size_t BLOCK_PARTS = 2;
+            size_t words_to_write = FL_PAGE_SZ / sizeof(uint32_t) / BLOCK_PARTS;
+            for (size_t i = 0; i < BLOCK_PARTS; i++) {
+                sd_flash_operation_start();
+                err_code = sd_flash_write(((uint32_t *)_flash_page_addr) + i * words_to_write,
+                                          (uint32_t *)_flash_cache + i * words_to_write,
+                                          words_to_write);
+                if (err_code != NRF_SUCCESS) {
+                    mp_raise_OSError_msg_varg(translate("Flash write failed to start, err 0x%04x"), err_code);
+                }
+                status = sd_flash_operation_wait_until_done();
+                if (status == SD_FLASH_OPERATION_ERROR) {
+                    mp_raise_OSError_msg(translate("Flash write failed"));
+                }
+            }
+        } else {
 #endif
-        nrf_nvmc_page_erase(_flash_page_addr);
-        nrf_nvmc_write_words(_flash_page_addr, (uint32_t *)_flash_cache, FL_PAGE_SZ / sizeof(uint32_t));
+            nrf_nvmc_page_erase(_flash_page_addr);
+            nrf_nvmc_write_words(_flash_page_addr, (uint32_t *)_flash_cache, FL_PAGE_SZ / sizeof(uint32_t));
 #ifdef BLUETOOTH_SD
-    }
+        }
 #endif
 
-    _flash_page_addr = NO_CACHE;
     }
+    _flash_page_addr = NO_CACHE;
 }
 
 mp_uint_t supervisor_flash_read_blocks(uint8_t *dest, uint32_t block, uint32_t num_blocks) {
+    // Must write out anything in cache before trying to read.
+    supervisor_flash_flush();
     uint32_t src = lba2addr(block);
     memcpy(dest, (uint8_t*) src, FILESYSTEM_BLOCK_SIZE*num_blocks);
     return 0; // success
@@ -139,9 +157,11 @@ mp_uint_t supervisor_flash_write_blocks(const uint8_t *src, uint32_t lba, uint32
             supervisor_flash_flush();
 
             _flash_page_addr = page_addr;
+            // Copy the current contents of the entire page into the cache.
             memcpy(_flash_cache, (void *)page_addr, FL_PAGE_SZ);
         }
 
+        // Overwrite part or all of the page cache with the src data.
         memcpy(_flash_cache + (addr & (FL_PAGE_SZ - 1)), src, count * FILESYSTEM_BLOCK_SIZE);
 
         // adjust for next run