diff --git a/include/ethosu_driver.h b/include/ethosu_driver.h
index 77a015c..9c9f173 100644
--- a/include/ethosu_driver.h
+++ b/include/ethosu_driver.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2022 Arm Limited. All rights reserved.
+ * SPDX-FileCopyrightText: Copyright 2019-2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: Apache-2.0
  *
@@ -215,7 +215,7 @@
  * @return 0 on success, else negative error code
  */
 int ethosu_init(struct ethosu_driver *drv,
-                const void *base_address,
+                void *const base_address,
                 const void *fast_memory,
                 const size_t fast_memory_size,
                 uint32_t secure_enable,
@@ -285,7 +285,7 @@
 int ethosu_invoke_v3(struct ethosu_driver *drv,
                      const void *custom_data_ptr,
                      const int custom_data_size,
-                     const uint64_t *base_addr,
+                     uint64_t *const base_addr,
                      const size_t *base_addr_size,
                      const int num_base_addr,
                      void *user_arg);
@@ -302,7 +302,7 @@
 int ethosu_invoke_async(struct ethosu_driver *drv,
                         const void *custom_data_ptr,
                         const int custom_data_size,
-                        const uint64_t *base_addr,
+                        uint64_t *const base_addr,
                         const size_t *base_addr_size,
                         const int num_base_addr,
                         void *user_arg);
@@ -340,11 +340,15 @@
  */
 static inline int ethosu_invoke_v2(const void *custom_data_ptr,
                                    const int custom_data_size,
-                                   const uint64_t *base_addr,
+                                   uint64_t *const base_addr,
                                    const size_t *base_addr_size,
                                    const int num_base_addr)
 {
     struct ethosu_driver *drv = ethosu_reserve_driver();
+    if (!drv)
+    {
+        return -1;
+    }
     int result = ethosu_invoke_v3(drv, custom_data_ptr, custom_data_size, base_addr, base_addr_size, num_base_addr, 0);
     ethosu_release_driver(drv);
     return result;
diff --git a/src/ethosu_device.h b/src/ethosu_device.h
index 0b45fd6..02942b1 100644
--- a/src/ethosu_device.h
+++ b/src/ethosu_device.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2022 Arm Limited. All rights reserved.
+ * SPDX-FileCopyrightText: Copyright 2019-2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: Apache-2.0
  *
@@ -59,7 +59,7 @@
 /**
  * Initialize the device.
  */
-struct ethosu_device *ethosu_dev_init(const void *base_address, uint32_t secure_enable, uint32_t privilege_enable);
+struct ethosu_device *ethosu_dev_init(void *const base_address, uint32_t secure_enable, uint32_t privilege_enable);
 
 /**
  * Deinitialize the device.
diff --git a/src/ethosu_device_u55_u65.c b/src/ethosu_device_u55_u65.c
index aec2027..50b78af 100644
--- a/src/ethosu_device_u55_u65.c
+++ b/src/ethosu_device_u55_u65.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2022 Arm Limited. All rights reserved.
+ * SPDX-FileCopyrightText: Copyright 2019-2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: Apache-2.0
  *
@@ -67,7 +67,7 @@
     return address;
 }
 
-struct ethosu_device *ethosu_dev_init(const void *base_address, uint32_t secure_enable, uint32_t privilege_enable)
+struct ethosu_device *ethosu_dev_init(void *const base_address, uint32_t secure_enable, uint32_t privilege_enable)
 {
     struct ethosu_device *dev = malloc(sizeof(struct ethosu_device));
     if (!dev)
@@ -167,7 +167,7 @@
     struct cmd_r cmd;
     uint64_t qbase = ethosu_address_remap((uintptr_t)cmd_stream_ptr, -1);
     assert(qbase <= ADDRESS_MASK);
-    LOG_DEBUG("QBASE=0x%016llx, QSIZE=%u, cmd_stream_ptr=%p", qbase, cms_length, cmd_stream_ptr);
+    LOG_DEBUG("QBASE=0x%016llx, QSIZE=%" PRIu32 ", cmd_stream_ptr=%p", qbase, cms_length, cmd_stream_ptr);
 
     dev->reg->QBASE.word[0] = qbase & 0xffffffff;
 #ifdef ETHOSU65
@@ -190,12 +190,12 @@
     cmd.transition_to_running_state = 1;
 
     dev->reg->CMD.word = cmd.word;
-    LOG_DEBUG("CMD=0x%08x", cmd.word);
+    LOG_DEBUG("CMD=0x%08" PRIx32, cmd.word);
 }
 
 void ethosu_dev_print_err_status(struct ethosu_device *dev)
 {
-    LOG_ERR("NPU status=0x%08" PRIx32 ", qread=%" PRIu32 ", cmd_end_reached=%d",
+    LOG_ERR("NPU status=0x%08" PRIx32 ", qread=%" PRIu32 ", cmd_end_reached=%u",
             dev->reg->STATUS.word,
             dev->reg->QREAD.word,
             dev->reg->STATUS.cmd_end_reached);
@@ -307,7 +307,7 @@
     }
 
     dev->reg->CMD.word = cmd.word;
-    LOG_DEBUG("CMD=0x%08x", cmd.word);
+    LOG_DEBUG("CMD=0x%08" PRIx32, cmd.word);
 
     return ETHOSU_SUCCESS;
 }
@@ -323,35 +323,35 @@
     hw_cfg.word = dev->reg->CONFIG.word;
     hw_id.word  = dev->reg->ID.word;
 
-    LOG_INFO("Optimizer config. product=%d, cmd_stream_version=%d, macs_per_cc=%d, shram_size=%d, custom_dma=%d",
+    LOG_INFO("Optimizer config. product=%u, cmd_stream_version=%u, macs_per_cc=%u, shram_size=%u, custom_dma=%u",
              opt_cfg->product,
              opt_cfg->cmd_stream_version,
              opt_cfg->macs_per_cc,
              opt_cfg->shram_size,
              opt_cfg->custom_dma);
-    LOG_INFO("Optimizer config. arch version: %d.%d.%d",
+    LOG_INFO("Optimizer config. arch version: %u.%u.%u",
              opt_id->arch_major_rev,
              opt_id->arch_minor_rev,
              opt_id->arch_patch_rev);
-    LOG_INFO("Ethos-U config. product=%d, cmd_stream_version=%d, macs_per_cc=%d, shram_size=%d, custom_dma=%d",
+    LOG_INFO("Ethos-U config. product=%u, cmd_stream_version=%u, macs_per_cc=%u, shram_size=%u, custom_dma=%u",
              hw_cfg.product,
              hw_cfg.cmd_stream_version,
              hw_cfg.macs_per_cc,
              hw_cfg.shram_size,
              hw_cfg.custom_dma);
-    LOG_INFO("Ethos-U. arch version=%d.%d.%d", hw_id.arch_major_rev, hw_id.arch_minor_rev, hw_id.arch_patch_rev);
+    LOG_INFO("Ethos-U. arch version=%u.%u.%u", hw_id.arch_major_rev, hw_id.arch_minor_rev, hw_id.arch_patch_rev);
 
     if (opt_cfg->word != hw_cfg.word)
     {
         if (hw_cfg.product != opt_cfg->product)
         {
-            LOG_ERR("NPU config mismatch. npu.product=%d, optimizer.product=%d", hw_cfg.product, opt_cfg->product);
+            LOG_ERR("NPU config mismatch. npu.product=%u, optimizer.product=%u", hw_cfg.product, opt_cfg->product);
             ret = false;
         }
 
         if (hw_cfg.macs_per_cc != opt_cfg->macs_per_cc)
         {
-            LOG_ERR("NPU config mismatch. npu.macs_per_cc=%d, optimizer.macs_per_cc=%d",
+            LOG_ERR("NPU config mismatch. npu.macs_per_cc=%u, optimizer.macs_per_cc=%u",
                     hw_cfg.macs_per_cc,
                     opt_cfg->macs_per_cc);
             ret = false;
@@ -359,7 +359,7 @@
 
         if (hw_cfg.cmd_stream_version != opt_cfg->cmd_stream_version)
         {
-            LOG_ERR("NPU config mismatch. npu.cmd_stream_version=%d, optimizer.cmd_stream_version=%d",
+            LOG_ERR("NPU config mismatch. npu.cmd_stream_version=%u, optimizer.cmd_stream_version=%u",
                     hw_cfg.cmd_stream_version,
                     opt_cfg->cmd_stream_version);
             ret = false;
@@ -367,7 +367,7 @@
 
         if (!hw_cfg.custom_dma && opt_cfg->custom_dma)
         {
-            LOG_ERR("NPU config mismatch. npu.custom_dma=%d, optimizer.custom_dma=%d",
+            LOG_ERR("NPU config mismatch. npu.custom_dma=%u, optimizer.custom_dma=%u",
                     hw_cfg.custom_dma,
                     opt_cfg->custom_dma);
             ret = false;
@@ -376,7 +376,7 @@
 
     if ((hw_id.arch_major_rev != opt_id->arch_major_rev) || (hw_id.arch_minor_rev < opt_id->arch_minor_rev))
     {
-        LOG_ERR("NPU arch mismatch. npu.arch=%d.%d.%d, optimizer.arch=%d.%d.%d",
+        LOG_ERR("NPU arch mismatch. npu.arch=%u.%u.%u, optimizer.arch=%u.%u.%u",
                 hw_id.arch_major_rev,
                 hw_id.arch_minor_rev,
                 hw_id.arch_patch_rev,
diff --git a/src/ethosu_driver.c b/src/ethosu_driver.c
index 2a28988..8fac936 100644
--- a/src/ethosu_driver.c
+++ b/src/ethosu_driver.c
@@ -184,7 +184,10 @@
 void *__attribute__((weak)) ethosu_semaphore_create(void)
 {
     struct ethosu_semaphore_t *sem = malloc(sizeof(*sem));
-    sem->count                     = 0;
+    if (sem != NULL)
+    {
+        sem->count = 0;
+    }
     return sem;
 }
 
@@ -284,9 +287,9 @@
     memset(&drv->job, 0, sizeof(struct ethosu_job));
 }
 
-static int handle_optimizer_config(struct ethosu_driver *drv, struct opt_cfg_s *opt_cfg_p)
+static int handle_optimizer_config(struct ethosu_driver *drv, struct opt_cfg_s const *opt_cfg_p)
 {
-    LOG_INFO("Optimizer release nbr: %d patch: %d", opt_cfg_p->da_data.rel_nbr, opt_cfg_p->da_data.patch_nbr);
+    LOG_INFO("Optimizer release nbr: %u patch: %u", opt_cfg_p->da_data.rel_nbr, opt_cfg_p->da_data.patch_nbr);
 
     if (ethosu_dev_verify_optimizer_config(drv->dev, opt_cfg_p->cfg, opt_cfg_p->id) != true)
     {
@@ -375,7 +378,7 @@
  ******************************************************************************/
 
 int ethosu_init(struct ethosu_driver *drv,
-                const void *base_address,
+                void *const base_address,
                 const void *fast_memory,
                 const size_t fast_memory_size,
                 uint32_t secure_enable,
@@ -585,7 +588,7 @@
 int ethosu_invoke_async(struct ethosu_driver *drv,
                         const void *custom_data_ptr,
                         const int custom_data_size,
-                        const uint64_t *base_addr,
+                        uint64_t *const base_addr,
                         const size_t *base_addr_size,
                         const int num_base_addr,
                         void *user_arg)
@@ -619,7 +622,7 @@
     // Custom data length must be a multiple of 32 bits
     if ((custom_data_size % BYTES_IN_32_BITS) != 0)
     {
-        LOG_ERR("custom_data_size=0x%x not a multiple of 4", custom_data_size);
+        LOG_ERR("custom_data_size=0x%x not a multiple of 4", (unsigned)custom_data_size);
         goto err;
     }
 
@@ -628,7 +631,6 @@
     // Adjust base address to fast memory area
     if (drv->fast_memory != 0 && num_base_addr >= FAST_MEMORY_BASE_ADDR_INDEX)
     {
-        uint64_t *fast_memory = (uint64_t *)&base_addr[FAST_MEMORY_BASE_ADDR_INDEX];
 
         if (base_addr_size != NULL && base_addr_size[FAST_MEMORY_BASE_ADDR_INDEX] > drv->fast_memory_size)
         {
@@ -638,7 +640,7 @@
             goto err;
         }
 
-        *fast_memory = drv->fast_memory;
+        base_addr[FAST_MEMORY_BASE_ADDR_INDEX] = drv->fast_memory;
     }
 
     drv->status_error = false;
@@ -650,7 +652,7 @@
         {
         case OPTIMIZER_CONFIG:
             LOG_DEBUG("OPTIMIZER_CONFIG");
-            struct opt_cfg_s *opt_cfg_p = (struct opt_cfg_s *)data_ptr;
+            struct opt_cfg_s const *opt_cfg_p = (const struct opt_cfg_s *)data_ptr;
 
             if (handle_optimizer_config(drv, opt_cfg_p) < 0)
             {
@@ -661,8 +663,8 @@
         case COMMAND_STREAM:
             // Vela only supports putting one COMMAND_STREAM per op
             LOG_DEBUG("COMMAND_STREAM");
-            void *command_stream = (uint8_t *)(data_ptr) + sizeof(struct cop_data_s);
-            int cms_length       = (data_ptr->reserved << 16) | data_ptr->length;
+            const uint8_t *command_stream = (const uint8_t *)(data_ptr + 1);
+            int cms_length                = (data_ptr->reserved << 16) | data_ptr->length;
 
             if (handle_command_stream(drv, command_stream, cms_length) < 0)
             {
@@ -675,7 +677,7 @@
             data_ptr += DRIVER_ACTION_LENGTH_32_BIT_WORD;
             break;
         default:
-            LOG_ERR("UNSUPPORTED driver_action_command: %d", data_ptr->driver_action_command);
+            LOG_ERR("UNSUPPORTED driver_action_command: %u", data_ptr->driver_action_command);
             goto err;
             break;
         }
@@ -691,7 +693,7 @@
 int ethosu_invoke_v3(struct ethosu_driver *drv,
                      const void *custom_data_ptr,
                      const int custom_data_size,
-                     const uint64_t *base_addr,
+                     uint64_t *const base_addr,
                      const size_t *base_addr_size,
                      const int num_base_addr,
                      void *user_arg)
diff --git a/src/ethosu_log.h b/src/ethosu_log.h
index 76fe292..582b91d 100644
--- a/src/ethosu_log.h
+++ b/src/ethosu_log.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Arm Limited. All rights reserved.
+ * SPDX-FileCopyrightText: Copyright 2021-2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: Apache-2.0
  *
@@ -42,29 +42,29 @@
 #endif
 
 // Log formatting
-
-#define LOG(f, ...) fprintf(stdout, f, ##__VA_ARGS__)
+#define LOG(f, ...) (void)fprintf(stdout, f, ##__VA_ARGS__)
 
 #if ETHOSU_LOG_SEVERITY >= ETHOSU_LOG_ERR
-#define LOG_ERR(f, ...) fprintf(stderr, "E: " f " (%s:%d)\n", ##__VA_ARGS__, strrchr("/" __FILE__, '/') + 1, __LINE__)
+#define LOG_ERR(f, ...)                                                                                                \
+    (void)fprintf(stderr, "E: " f " (%s:%d)\n", ##__VA_ARGS__, strrchr("/" __FILE__, '/') + 1, __LINE__)
 #else
 #define LOG_ERR(f, ...)
 #endif
 
 #if ETHOSU_LOG_SEVERITY >= ETHOSU_LOG_WARN
-#define LOG_WARN(f, ...) fprintf(stdout, "W: " f "\n", ##__VA_ARGS__)
+#define LOG_WARN(f, ...) (void)fprintf(stdout, "W: " f "\n", ##__VA_ARGS__)
 #else
 #define LOG_WARN(f, ...)
 #endif
 
 #if ETHOSU_LOG_SEVERITY >= ETHOSU_LOG_INFO
-#define LOG_INFO(f, ...) fprintf(stdout, "I: " f "\n", ##__VA_ARGS__)
+#define LOG_INFO(f, ...) (void)fprintf(stdout, "I: " f "\n", ##__VA_ARGS__)
 #else
 #define LOG_INFO(f, ...)
 #endif
 
 #if ETHOSU_LOG_SEVERITY >= ETHOSU_LOG_DEBUG
-#define LOG_DEBUG(f, ...) fprintf(stdout, "D: %s(): " f "\n", __FUNCTION__, ##__VA_ARGS__)
+#define LOG_DEBUG(f, ...) (void)fprintf(stdout, "D: %s(): " f "\n", __FUNCTION__, ##__VA_ARGS__)
 #else
 #define LOG_DEBUG(f, ...)
 #endif
diff --git a/src/ethosu_pmu.c b/src/ethosu_pmu.c
index af4e503..b5925c4 100644
--- a/src/ethosu_pmu.c
+++ b/src/ethosu_pmu.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2022 Arm Limited.
+ * SPDX-FileCopyrightText: Copyright 2019-2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
  *
  * SPDX-License-Identifier: Apache-2.0
  *
@@ -110,7 +110,7 @@
 {
     assert(num < ETHOSU_PMU_NCOUNTERS);
     uint32_t val = pmu_event_value(type);
-    LOG_DEBUG("num=%u, type=%d, val=%u", num, type, val);
+    LOG_DEBUG("num=%" PRIu32 ", type=%d, val=%" PRIu32, num, type, val);
     drv->dev->reg->PMEVTYPER[num].word = val;
 }
 
@@ -119,7 +119,7 @@
     assert(num < ETHOSU_PMU_NCOUNTERS);
     uint32_t val                    = drv->dev->reg->PMEVTYPER[num].word;
     enum ethosu_pmu_event_type type = pmu_event_type(val);
-    LOG_DEBUG("num=%u, type=%d, val=%u", num, type, val);
+    LOG_DEBUG("num=%" PRIu32 ", type=%d, val=%" PRIu32, num, type, val);
     return type;
 }
 
@@ -143,20 +143,20 @@
 
 void ETHOSU_PMU_CNTR_Enable(struct ethosu_driver *drv, uint32_t mask)
 {
-    LOG_DEBUG("mask=0x%08x", mask);
+    LOG_DEBUG("mask=0x%08" PRIx32, mask);
     drv->dev->reg->PMCNTENSET.word = mask;
 }
 
 void ETHOSU_PMU_CNTR_Disable(struct ethosu_driver *drv, uint32_t mask)
 {
-    LOG_DEBUG("mask=0x%08x", mask);
+    LOG_DEBUG("mask=0x%08" PRIx32, mask);
     drv->dev->reg->PMCNTENCLR.word = mask;
 }
 
 uint32_t ETHOSU_PMU_CNTR_Status(struct ethosu_driver *drv)
 {
     uint32_t pmcntenset = drv->dev->reg->PMCNTENSET.word;
-    LOG_DEBUG("mask=0x%08x", pmcntenset);
+    LOG_DEBUG("mask=0x%08" PRIx32, pmcntenset);
     return pmcntenset;
 }
 
@@ -194,7 +194,7 @@
 {
     assert(num < ETHOSU_PMU_NCOUNTERS);
     uint32_t val = drv->dev->reg->PMEVCNTR[num].word;
-    LOG_DEBUG("num=%u, val=%u", num, val);
+    LOG_DEBUG("num=%" PRIu32 ", val=%" PRIu32, num, val);
 
     return val;
 }
@@ -202,7 +202,7 @@
 void ETHOSU_PMU_Set_EVCNTR(struct ethosu_driver *drv, uint32_t num, uint32_t val)
 {
     assert(num < ETHOSU_PMU_NCOUNTERS);
-    LOG_DEBUG("num=%u, val=%u", num, val);
+    LOG_DEBUG("num=%" PRIu32 ", val=%" PRIu32, num, val);
     drv->dev->reg->PMEVCNTR[num].word = val;
 }
 
@@ -220,20 +220,20 @@
 
 void ETHOSU_PMU_Set_CNTR_IRQ_Enable(struct ethosu_driver *drv, uint32_t mask)
 {
-    LOG_DEBUG("mask=0x%08x", mask);
+    LOG_DEBUG("mask=0x%08" PRIx32, mask);
     drv->dev->reg->PMINTSET.word = mask;
 }
 
 void ETHOSU_PMU_Set_CNTR_IRQ_Disable(struct ethosu_driver *drv, uint32_t mask)
 {
-    LOG_DEBUG("mask=0x%08x", mask);
+    LOG_DEBUG("mask=0x%08" PRIx32, mask);
     drv->dev->reg->PMINTCLR.word = mask;
 }
 
 uint32_t ETHOSU_PMU_Get_IRQ_Enable(struct ethosu_driver *drv)
 {
     uint32_t pmint = drv->dev->reg->PMINTSET.word;
-    LOG_DEBUG("mask=0x%08x", pmint);
+    LOG_DEBUG("mask=0x%08" PRIx32, pmint);
     return pmint;
 }
 
@@ -255,7 +255,7 @@
 
     for (int i = 0; i < ETHOSU_PMU_NCOUNTERS; i++)
     {
-        if (mask & (1 << i))
+        if (mask & (1u << i))
         {
             uint32_t val                    = ETHOSU_PMU_Get_EVCNTR(drv, i);
             drv->dev->reg->PMEVCNTR[i].word = val + 1;
@@ -289,13 +289,13 @@
 uint32_t ETHOSU_PMU_Get_QREAD(struct ethosu_driver *drv)
 {
     uint32_t val = drv->dev->reg->QREAD.word;
-    LOG_DEBUG("qread=%u", val);
+    LOG_DEBUG("qread=%" PRIu32, val);
     return val;
 }
 
 uint32_t ETHOSU_PMU_Get_STATUS(struct ethosu_driver *drv)
 {
     uint32_t val = drv->dev->reg->STATUS.word;
-    LOG_DEBUG("status=0x%x", val);
+    LOG_DEBUG("status=0x%" PRIx32, val);
     return val;
 }