diff --git a/libraries/AP_HAL_ChibiOS/Device.h b/libraries/AP_HAL_ChibiOS/Device.h
index 9bd218d412..8225e017d9 100644
--- a/libraries/AP_HAL_ChibiOS/Device.h
+++ b/libraries/AP_HAL_ChibiOS/Device.h
@@ -16,7 +16,11 @@
 
 #include <inttypes.h>
 #include <AP_HAL/HAL.h>
+#if !defined(HAL_BOOTLOADER_BUILD)
 #include "Semaphores.h"
+#else
+#include <AP_HAL_Empty/Semaphores.h>
+#endif
 #include "AP_HAL_ChibiOS.h"
 
 #if HAL_USE_I2C == TRUE || HAL_USE_SPI == TRUE || HAL_USE_WSPI == TRUE
@@ -34,7 +38,11 @@ public:
     DeviceBus(uint8_t _thread_priority, bool axi_sram);
 
     struct DeviceBus *next;
+#if defined(HAL_BOOTLOADER_BUILD)
+    Empty::Semaphore semaphore;
+#else
     Semaphore semaphore;
+#endif
     Shared_DMA *dma_handle;
 
     AP_HAL::Device::PeriodicHandle register_periodic_callback(uint32_t period_usec, AP_HAL::Device::PeriodicCb, AP_HAL::Device *hal_device);
diff --git a/libraries/AP_HAL_ChibiOS/QSPIDevice.cpp b/libraries/AP_HAL_ChibiOS/QSPIDevice.cpp
index a4abdd6e52..04ec03ce7e 100644
--- a/libraries/AP_HAL_ChibiOS/QSPIDevice.cpp
+++ b/libraries/AP_HAL_ChibiOS/QSPIDevice.cpp
@@ -25,7 +25,6 @@
 #include <AP_InternalError/AP_InternalError.h>
 #include "Util.h"
 #include "Scheduler.h"
-#include "Semaphores.h"
 #include <stdio.h>
 #include "hwdef/common/stm32_util.h"
 
diff --git a/libraries/AP_HAL_ChibiOS/QSPIDevice.h b/libraries/AP_HAL_ChibiOS/QSPIDevice.h
index e3f8c3469e..5c04845a57 100644
--- a/libraries/AP_HAL_ChibiOS/QSPIDevice.h
+++ b/libraries/AP_HAL_ChibiOS/QSPIDevice.h
@@ -26,7 +26,10 @@
 
 #if HAL_USE_WSPI == TRUE && defined(HAL_QSPI_DEVICE_LIST)
 
+#if !defined(HAL_BOOTLOADER_BUILD)
 #include "Semaphores.h"
+#endif
+
 #include "Scheduler.h"
 #include "Device.h"
 
@@ -99,8 +102,12 @@ public:
 
     AP_HAL::Semaphore* get_semaphore() override
     {
+#if !defined(HAL_BOOTLOADER_BUILD)
         // if asking for invalid bus number use bus 0 semaphore
         return &bus.semaphore;
+#else
+        return nullptr;
+#endif
     }
 
     bool acquire_bus(bool acquire);
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
index 3cc0e66acd..a5ecb13b23 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
@@ -884,19 +884,19 @@ def write_mcu_config(f):
 #define HAL_NO_RCIN_THREAD
 #define HAL_NO_SHARED_DMA FALSE
 #define HAL_NO_ROMFS_SUPPORT TRUE
-''')
-        if not env_vars['EXTERNAL_PROG_FLASH_MB']:
-            f.write('''
 #define CH_CFG_USE_TM FALSE
 #define CH_CFG_USE_REGISTRY FALSE
 #define CH_CFG_USE_WAITEXIT FALSE
 #define CH_CFG_USE_MEMPOOLS FALSE
 #define CH_DBG_FILL_THREADS FALSE
-#define CH_CFG_USE_SEMAPHORES FALSE
-#define CH_CFG_USE_HEAP FALSE
 #define CH_CFG_USE_MUTEXES FALSE
 #define CH_CFG_USE_EVENTS FALSE
 #define CH_CFG_USE_EVENTS_TIMEOUT FALSE
+''')
+        if not env_vars['EXTERNAL_PROG_FLASH_MB']:
+            f.write('''
+#define CH_CFG_USE_HEAP FALSE
+#define CH_CFG_USE_SEMAPHORES FALSE
 #define CH_CFG_USE_MEMCORE FALSE
 ''')
     if env_vars.get('ROMFS_UNCOMPRESSED', False):