diff --git a/bl1/bl1_fwu.c b/bl1/bl1_fwu.c
index 57a86ae..c233016 100644
--- a/bl1/bl1_fwu.c
+++ b/bl1/bl1_fwu.c
@@ -52,9 +52,6 @@
  */
 static unsigned int sec_exec_image_id = INVALID_IMAGE_ID;
 
-/* Authentication status of each image. */
-extern unsigned int auth_img_flags[MAX_NUMBER_IDS];
-
 /*******************************************************************************
  * Top level handler for servicing FWU SMCs.
  ******************************************************************************/
diff --git a/drivers/arm/css/scmi/scmi_ap_core_proto.c b/drivers/arm/css/scmi/scmi_ap_core_proto.c
index 2caccc2..5941b87 100644
--- a/drivers/arm/css/scmi/scmi_ap_core_proto.c
+++ b/drivers/arm/css/scmi/scmi_ap_core_proto.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -18,7 +18,8 @@
 int scmi_ap_core_set_reset_addr(void *p, uint64_t reset_addr, uint32_t attr)
 {
 	mailbox_mem_t *mbx_mem;
-	int token = 0, ret;
+	unsigned int token = 0;
+	int ret;
 	scmi_channel_t *ch = (scmi_channel_t *)p;
 
 	validate_scmi_channel(ch);
@@ -51,7 +52,8 @@
 int scmi_ap_core_get_reset_addr(void *p, uint64_t *reset_addr, uint32_t *attr)
 {
 	mailbox_mem_t *mbx_mem;
-	int token = 0, ret;
+	unsigned int token = 0;
+	int ret;
 	scmi_channel_t *ch = (scmi_channel_t *)p;
 	uint32_t lo_addr, hi_addr;
 
diff --git a/drivers/arm/css/scmi/scmi_common.c b/drivers/arm/css/scmi/scmi_common.c
index e2c353d..5b3724a 100644
--- a/drivers/arm/css/scmi/scmi_common.c
+++ b/drivers/arm/css/scmi/scmi_common.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -90,7 +90,8 @@
 int scmi_proto_version(void *p, uint32_t proto_id, uint32_t *version)
 {
 	mailbox_mem_t *mbx_mem;
-	int token = 0, ret;
+	unsigned int token = 0;
+	int ret;
 	scmi_channel_t *ch = (scmi_channel_t *)p;
 
 	validate_scmi_channel(ch);
@@ -122,7 +123,8 @@
 		uint32_t command_id, uint32_t *attr)
 {
 	mailbox_mem_t *mbx_mem;
-	int token = 0, ret;
+	unsigned int token = 0;
+	int ret;
 	scmi_channel_t *ch = (scmi_channel_t *)p;
 
 	validate_scmi_channel(ch);
diff --git a/drivers/arm/css/scmi/scmi_pwr_dmn_proto.c b/drivers/arm/css/scmi/scmi_pwr_dmn_proto.c
index 70165de..a342aa8 100644
--- a/drivers/arm/css/scmi/scmi_pwr_dmn_proto.c
+++ b/drivers/arm/css/scmi/scmi_pwr_dmn_proto.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -19,7 +19,8 @@
 					uint32_t scmi_pwr_state)
 {
 	mailbox_mem_t *mbx_mem;
-	int token = 0, ret;
+	unsigned int token = 0;
+	int ret;
 
 	/*
 	 * Only asynchronous mode of `set power state` command is allowed on
@@ -59,7 +60,8 @@
 					uint32_t *scmi_pwr_state)
 {
 	mailbox_mem_t *mbx_mem;
-	int token = 0, ret;
+	unsigned int token = 0;
+	int ret;
 	scmi_channel_t *ch = (scmi_channel_t *)p;
 
 	validate_scmi_channel(ch);
diff --git a/drivers/arm/css/scmi/scmi_sys_pwr_proto.c b/drivers/arm/css/scmi/scmi_sys_pwr_proto.c
index a27c4a5..c8e62d1 100644
--- a/drivers/arm/css/scmi/scmi_sys_pwr_proto.c
+++ b/drivers/arm/css/scmi/scmi_sys_pwr_proto.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -18,7 +18,8 @@
 int scmi_sys_pwr_state_set(void *p, uint32_t flags, uint32_t system_state)
 {
 	mailbox_mem_t *mbx_mem;
-	int token = 0, ret;
+	unsigned int token = 0;
+	int ret;
 	scmi_channel_t *ch = (scmi_channel_t *)p;
 
 	validate_scmi_channel(ch);
@@ -50,7 +51,8 @@
 int scmi_sys_pwr_state_get(void *p, uint32_t *system_state)
 {
 	mailbox_mem_t *mbx_mem;
-	int token = 0, ret;
+	unsigned int token = 0;
+	int ret;
 	scmi_channel_t *ch = (scmi_channel_t *)p;
 
 	validate_scmi_channel(ch);
diff --git a/drivers/arm/css/scp/css_pm_scmi.c b/drivers/arm/css/scp/css_pm_scmi.c
index 1966c44..8dbefa1 100644
--- a/drivers/arm/css/scp/css_pm_scmi.c
+++ b/drivers/arm/css/scp/css_pm_scmi.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -99,7 +99,7 @@
 		return;
 	}
 #if !HW_ASSISTED_COHERENCY
-	int lvl;
+	unsigned int lvl;
 	uint32_t scmi_pwr_state = 0;
 	/*
 	 * If we reach here, then assert that power down at system power domain
@@ -145,7 +145,8 @@
  */
 void css_scp_off(const struct psci_power_state *target_state)
 {
-	int lvl = 0, ret;
+	unsigned int lvl = 0;
+	int ret;
 	uint32_t scmi_pwr_state = 0;
 
 	/* At-least the CPU level should be specified to be OFF */
@@ -184,7 +185,8 @@
  */
 void css_scp_on(u_register_t mpidr)
 {
-	int lvl = 0, ret, core_pos;
+	unsigned int lvl = 0;
+	int ret, core_pos;
 	uint32_t scmi_pwr_state = 0;
 
 	for (; lvl <= PLAT_MAX_PWR_LVL; lvl++)
diff --git a/drivers/arm/sp804/sp804_delay_timer.c b/drivers/arm/sp804/sp804_delay_timer.c
index 5313fbd..9c5e762 100644
--- a/drivers/arm/sp804/sp804_delay_timer.c
+++ b/drivers/arm/sp804/sp804_delay_timer.c
@@ -1,11 +1,12 @@
 /*
- * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
 #include <assert.h>
 
+#include <drivers/arm/sp804_delay_timer.h>
 #include <drivers/delay_timer.h>
 #include <lib/mmio.h>
 
diff --git a/drivers/auth/auth_mod.c b/drivers/auth/auth_mod.c
index 1b8ff82..97e1220 100644
--- a/drivers/auth/auth_mod.c
+++ b/drivers/auth/auth_mod.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -30,10 +30,6 @@
 
 #pragma weak plat_set_nv_ctr2
 
-/* Pointer to CoT */
-extern const auth_img_desc_t *const cot_desc_ptr;
-extern unsigned int auth_img_flags[MAX_NUMBER_IDS];
-
 static int cmp_auth_param_type_desc(const auth_param_type_desc_t *a,
 		const auth_param_type_desc_t *b)
 {
diff --git a/drivers/console/multi_console.c b/drivers/console/multi_console.c
index a135959..b5ff88b 100644
--- a/drivers/console/multi_console.c
+++ b/drivers/console/multi_console.c
@@ -13,11 +13,11 @@
 console_t *console_list;
 uint8_t console_state = CONSOLE_FLAG_BOOT;
 
+IMPORT_SYM(console_t *, __STACKS_START__, stacks_start)
+IMPORT_SYM(console_t *, __STACKS_END__, stacks_end)
+
 int console_register(console_t *console)
 {
-	IMPORT_SYM(console_t *, __STACKS_START__, stacks_start)
-	IMPORT_SYM(console_t *, __STACKS_END__, stacks_end)
-
 	/* Assert that the struct is not on the stack (common mistake). */
 	assert((console < stacks_start) || (console >= stacks_end));
 	/* Assert that we won't make a circle in the list. */
diff --git a/lib/semihosting/semihosting.c b/lib/semihosting/semihosting.c
index ee48dbc..051dd00 100644
--- a/lib/semihosting/semihosting.c
+++ b/lib/semihosting/semihosting.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -160,7 +160,7 @@
 long semihosting_get_flen(const char *file_name)
 {
 	long file_handle;
-	size_t length;
+	long length;
 
 	assert(semihosting_connection_supported());
 
diff --git a/plat/arm/board/juno/juno_bl1_setup.c b/plat/arm/board/juno/juno_bl1_setup.c
index f72a6ff..33f5c47 100644
--- a/plat/arm/board/juno/juno_bl1_setup.c
+++ b/plat/arm/board/juno/juno_bl1_setup.c
@@ -61,7 +61,7 @@
  ******************************************************************************/
 int plat_arm_bl1_fwu_needed(void)
 {
-	const uint32_t *nv_flags_ptr = (const uint32_t *)V2M_SYS_NVFLAGS_ADDR;
+	const int32_t *nv_flags_ptr = (const int32_t *)V2M_SYS_NVFLAGS_ADDR;
 
 	/* Check if TOC is invalid or watchdog reset happened. */
 	if ((arm_io_is_toc_valid() != 1) ||
diff --git a/services/std_svc/spm/spm_buffers.c b/services/std_svc/spm/spm_buffers.c
index 736b230..3e0c949 100644
--- a/services/std_svc/spm/spm_buffers.c
+++ b/services/std_svc/spm/spm_buffers.c
@@ -42,7 +42,7 @@
 		}
 	}
 
-	for (int i = 0; i < ARRAY_SIZE(responses); i++) {
+	for (unsigned int i = 0U; i < ARRAY_SIZE(responses); i++) {
 		struct sprt_response *resp = &(responses[i]);
 
 		if (resp->is_valid == 0) {