diff --git a/plat/intel/soc/common/include/socfpga_mailbox.h b/plat/intel/soc/common/include/socfpga_mailbox.h
index 38f4696..7d725b0 100644
--- a/plat/intel/soc/common/include/socfpga_mailbox.h
+++ b/plat/intel/soc/common/include/socfpga_mailbox.h
@@ -126,21 +126,21 @@
 void mailbox_set_qspi_close(void);
 void mailbox_set_qspi_open(void);
 void mailbox_set_qspi_direct(void);
-int mailbox_send_cmd(int job_id, unsigned int cmd, uint32_t *args,
+int mailbox_send_cmd(int job_id, unsigned int cmd, uint64_t *args,
 			int len, int urgent, uint32_t *response, int resp_len);
-int mailbox_send_cmd_async(int job_id, unsigned int cmd, uint32_t *args,
+int mailbox_send_cmd_async(int job_id, unsigned int cmd, uint64_t *args,
 				int len, int urgent);
 int mailbox_read_response(int job_id, uint32_t *response, int resp_len);
 int mailbox_get_qspi_clock(void);
 void mailbox_reset_cold(void);
 void mailbox_clear_response(void);
 
-uint32_t intel_mailbox_get_config_status(uint32_t cmd);
+int intel_mailbox_get_config_status(uint32_t cmd);
 int intel_mailbox_is_fpga_not_ready(void);
 
 int mailbox_rsu_get_spt_offset(uint32_t *resp_buf, uint32_t resp_buf_len);
 int mailbox_rsu_status(uint32_t *resp_buf, uint32_t resp_buf_len);
-int mailbox_rsu_update(uint32_t *flash_offset);
-int mailbox_hps_stage_notify(uint32_t execution_stage);
+int mailbox_rsu_update(uint64_t *flash_offset);
+int mailbox_hps_stage_notify(uint64_t execution_stage);
 
 #endif /* SOCFPGA_MBOX_H */
diff --git a/plat/intel/soc/common/soc/socfpga_mailbox.c b/plat/intel/soc/common/soc/socfpga_mailbox.c
index 673c2d5..8ce40a7 100644
--- a/plat/intel/soc/common/soc/socfpga_mailbox.c
+++ b/plat/intel/soc/common/soc/socfpga_mailbox.c
@@ -11,7 +11,7 @@
 #include "socfpga_mailbox.h"
 #include "socfpga_sip_svc.h"
 
-static int fill_mailbox_circular_buffer(uint32_t header_cmd, uint32_t *args,
+static int fill_mailbox_circular_buffer(uint32_t header_cmd, uint64_t *args,
 					int len)
 {
 	uint32_t cmd_free_offset;
@@ -167,7 +167,7 @@
 	}
 }
 
-int mailbox_send_cmd_async(int job_id, unsigned int cmd, uint32_t *args,
+int mailbox_send_cmd_async(int job_id, unsigned int cmd, uint64_t *args,
 			  int len, int urgent)
 {
 	if (urgent)
@@ -184,7 +184,7 @@
 	return 0;
 }
 
-int mailbox_send_cmd(int job_id, unsigned int cmd, uint32_t *args,
+int mailbox_send_cmd(int job_id, unsigned int cmd, uint64_t *args,
 			int len, int urgent, uint32_t *response, int resp_len)
 {
 	int status = 0;
@@ -252,7 +252,7 @@
 
 void mailbox_qspi_set_cs(int device_select)
 {
-	uint32_t cs_setting = device_select;
+	uint64_t cs_setting = device_select;
 
 	/* QSPI device select settings at 31:28 */
 	cs_setting = (cs_setting << 28);
@@ -304,13 +304,13 @@
 	return ret;
 }
 
-int mailbox_rsu_update(uint32_t *flash_offset)
+int mailbox_rsu_update(uint64_t *flash_offset)
 {
 	return mailbox_send_cmd(MBOX_JOB_ID, MBOX_RSU_UPDATE,
-				(uint32_t *)flash_offset, 2, 0, NULL, 0);
+				flash_offset, 2, 0, NULL, 0);
 }
 
-int mailbox_hps_stage_notify(uint32_t execution_stage)
+int mailbox_hps_stage_notify(uint64_t execution_stage)
 {
 	return mailbox_send_cmd(MBOX_JOB_ID, MBOX_HPS_STAGE_NOTIFY,
 				&execution_stage, 1, 0, NULL, 0);
@@ -336,10 +336,10 @@
 	return 0;
 }
 
-uint32_t intel_mailbox_get_config_status(uint32_t cmd)
+int intel_mailbox_get_config_status(uint32_t cmd)
 {
-	uint32_t status, res;
-	uint32_t response[6];
+	int status;
+	uint32_t res, response[6];
 
 	status = mailbox_send_cmd(1, cmd, NULL, 0, 0, response,
 		sizeof(response) / sizeof(response[0]));
diff --git a/plat/intel/soc/common/socfpga_psci.c b/plat/intel/soc/common/socfpga_psci.c
index d27ab9f..d48fb5d 100644
--- a/plat/intel/soc/common/socfpga_psci.c
+++ b/plat/intel/soc/common/socfpga_psci.c
@@ -135,7 +135,7 @@
 static void __dead2 socfpga_system_reset(void)
 {
 	if (intel_rsu_update_address)
-		mailbox_rsu_update((uint32_t *)&intel_rsu_update_address);
+		mailbox_rsu_update(&intel_rsu_update_address);
 	else
 		mailbox_reset_cold();
 
diff --git a/plat/intel/soc/common/socfpga_sip_svc.c b/plat/intel/soc/common/socfpga_sip_svc.c
index 5b600e5..1c3d45b 100644
--- a/plat/intel/soc/common/socfpga_sip_svc.c
+++ b/plat/intel/soc/common/socfpga_sip_svc.c
@@ -61,7 +61,7 @@
 
 static int intel_fpga_sdm_write_buffer(struct fpga_config_info *buffer)
 {
-	uint32_t args[3];
+	uint64_t args[3];
 
 	while (max_blocks > 0 && buffer->size > buffer->size_written) {
 		args[0] = (1<<8);
@@ -256,7 +256,7 @@
 {
 	if (size > (UINT64_MAX - addr))
 		return false;
-	if (addr < DRAM_BASE)
+	if (addr < BL31_LIMIT)
 		return false;
 	if (addr + size > DRAM_BASE + DRAM_SIZE)
 		return false;
@@ -387,7 +387,7 @@
 
 static uint32_t intel_rsu_notify(uint64_t execution_stage)
 {
-	if (mailbox_hps_stage_notify((uint32_t)execution_stage) < 0)
+	if (mailbox_hps_stage_notify(execution_stage) < 0)
 		return INTEL_SIP_SMC_STATUS_ERROR;
 
 	return INTEL_SIP_SMC_STATUS_OK;
@@ -404,7 +404,7 @@
 }
 
 /* Mailbox services */
-static uint32_t intel_mbox_send_cmd(uint32_t cmd, uint32_t *args, int len,
+static uint32_t intel_mbox_send_cmd(uint32_t cmd, uint64_t *args, int len,
 				    int urgent, uint32_t *response,
 				    int resp_len, int *mbox_status,
 				    int *len_in_resp)
@@ -542,7 +542,7 @@
 	case INTEL_SIP_SMC_MBOX_SEND_CMD:
 		x5 = SMC_GET_GP(handle, CTX_GPREG_X5);
 		x6 = SMC_GET_GP(handle, CTX_GPREG_X6);
-		status = intel_mbox_send_cmd(x1, (uint32_t *)x2, x3, x4,
+		status = intel_mbox_send_cmd(x1, (uint64_t *)x2, x3, x4,
 					     (uint32_t *)x5, x6, &mbox_status,
 					     &len_in_resp);
 		SMC_RET4(handle, status, mbox_status, x5, len_in_resp);