diff --git a/ports/stm32/boards/NUCLEO_WB55/rfcore.py b/ports/stm32/boards/NUCLEO_WB55/rfcore.py
index e612499a78..cfe315605e 100644
--- a/ports/stm32/boards/NUCLEO_WB55/rfcore.py
+++ b/ports/stm32/boards/NUCLEO_WB55/rfcore.py
@@ -34,10 +34,15 @@
 # to print out SRAM2A, register state and FUS/WS info.
 
 from machine import mem8, mem16, mem32
-import time, struct, uctypes
+import time, struct
 import stm
 
 
+def addressof(buf):
+    assert type(buf) is bytearray
+    return mem32[id(buf) + 12]
+
+
 class Flash:
     FLASH_KEY1 = 0x45670123
     FLASH_KEY2 = 0xCDEF89AB
@@ -68,7 +73,7 @@ class Flash:
         self.wait_not_busy()
         cr = 1 << 0  # PG
         mem32[stm.FLASH + stm.FLASH_CR] = cr
-        buf_addr = uctypes.addressof(buf)
+        buf_addr = addressof(buf)
         off = 0
         while off < len(buf):
             mem32[addr + off] = mem32[buf_addr + off]
@@ -111,13 +116,6 @@ OCF_FUS_FW_DELETE = const(0x55)
 OCF_FUS_START_WS = const(0x5A)
 OCF_BLE_INIT = const(0x66)
 
-
-@micropython.asm_thumb
-def asm_sev_wfe():
-    data(2, 0xBF40)  # sev
-    data(2, 0xBF20)  # wfe
-
-
 TABLE_DEVICE_INFO = const(0)
 TABLE_BLE = const(1)
 TABLE_SYS = const(3)
@@ -199,6 +197,9 @@ def ipcc_init():
     BLE_EVT_QUEUE = get_ipcc_table_word(TABLE_BLE, 2)
     BLE_HCI_ACL_DATA_BUF = get_ipcc_table_word(TABLE_BLE, 3)
 
+    # Disable interrupts, the code here uses polling
+    mem32[stm.IPCC + stm.IPCC_C1CR] = 0
+
     print("IPCC initialised")
     print("SYS: 0x%08x 0x%08x" % (SYS_CMD_BUF, SYS_SYS_QUEUE))
     print("BLE: 0x%08x 0x%08x 0x%08x" % (BLE_CMD_BUF, BLE_CS_BUF, BLE_EVT_QUEUE))
diff --git a/ports/stm32/rfcore.c b/ports/stm32/rfcore.c
index ca2ad747c4..dc23bbe0b2 100644
--- a/ports/stm32/rfcore.c
+++ b/ports/stm32/rfcore.c
@@ -94,15 +94,35 @@ typedef struct _parse_hci_info_t {
 // [16:23] = SRAM2b (Number of 1k sectors)
 // [24:31] = SRAM2a (Number of 1k sectors)
 
-typedef struct __attribute__((packed)) _ipcc_device_info_table_t {
-    uint32_t safeboot_version;
-    uint32_t fus_version;
-    uint32_t fus_memorysize;
-    uint32_t fus_info;
-    uint32_t fw_version;
-    uint32_t fw_memorysize;
-    uint32_t fw_infostack;
-    uint32_t fw_reserved;
+typedef union __attribute__((packed)) _ipcc_device_info_table_t {
+    struct {
+        uint32_t table_state;
+        uint8_t reserved0;
+        uint8_t last_fus_state;
+        uint8_t last_ws_state;
+        uint8_t ws_type;
+        uint32_t safeboot_version;
+        uint32_t fus_version;
+        uint32_t fus_memorysize;
+        uint32_t ws_version;
+        uint32_t ws_memorysize;
+        uint32_t ws_ble_info;
+        uint32_t ws_thread_info;
+        uint32_t reserved1;
+        uint64_t uid64;
+        uint16_t device_id;
+        uint16_t pad;
+    } fus;
+    struct {
+        uint32_t safeboot_version;
+        uint32_t fus_version;
+        uint32_t fus_memorysize;
+        uint32_t fus_info;
+        uint32_t fw_version;
+        uint32_t fw_memorysize;
+        uint32_t fw_infostack;
+        uint32_t fw_reserved;
+    } ws;
 } ipcc_device_info_table_t;
 
 typedef struct __attribute__((packed)) _ipcc_ble_table_t {