diff --git a/mongoose.c b/mongoose.c
index 62fde56a..8bb6ec21 100644
--- a/mongoose.c
+++ b/mongoose.c
@@ -664,7 +664,7 @@ MG_IRAM bool mg_flash_erase(void *addr) {
   return ok;
 }
 
-MG_IRAM bool mg_flash_swap_bank() {
+MG_IRAM bool mg_flash_swap_bank(void) {
   return true;
 }
 
@@ -1007,7 +1007,7 @@ MG_IRAM bool mg_flash_erase(void *addr) {
   return ok;
 }
 
-MG_IRAM bool mg_flash_swap_bank() {
+MG_IRAM bool mg_flash_swap_bank(void) {
   if (mg_flash_bank() == 0) return true;
   uint32_t bank = FLASH_BASE1;
   uint32_t desired = flash_bank_is_swapped(bank) ? 0 : MG_BIT(31);
diff --git a/mongoose.h b/mongoose.h
index 9ae50713..b6a408a6 100644
--- a/mongoose.h
+++ b/mongoose.h
@@ -1055,9 +1055,9 @@ uint64_t mg_now(void);     // Return milliseconds since Epoch
 #define mg_htons(x) mg_ntohs(x)
 #define mg_htonl(x) mg_ntohl(x)
 
-#define MG_U32(a, b, c, d)                                         \
-  (((uint32_t) ((a) &255) << 24) | ((uint32_t) ((b) &255) << 16) | \
-   ((uint32_t) ((c) &255) << 8) | (uint32_t) ((d) &255))
+#define MG_U32(a, b, c, d)                                           \
+  (((uint32_t) ((a) & 255) << 24) | ((uint32_t) ((b) & 255) << 16) | \
+   ((uint32_t) ((c) & 255) << 8) | (uint32_t) ((d) & 255))
 
 // For printing IPv4 addresses: printf("%d.%d.%d.%d\n", MG_IPADDR_PARTS(&ip))
 #define MG_U8P(ADDR) ((uint8_t *) (ADDR))
@@ -1071,9 +1071,12 @@ uint64_t mg_now(void);     // Return milliseconds since Epoch
 #define MG_ROUND_UP(x, a) ((a) == 0 ? (x) : ((((x) + (a) -1) / (a)) * (a)))
 #define MG_ROUND_DOWN(x, a) ((a) == 0 ? (x) : (((x) / (a)) * (a)))
 
-#ifdef __GNUC__
+#if defined(__GNUC__)
 #define MG_ARM_DISABLE_IRQ() asm volatile("cpsid i" : : : "memory")
 #define MG_ARM_ENABLE_IRQ() asm volatile("cpsie i" : : : "memory")
+#elif defined(__CCRH__)
+#define MG_RH850_DISABLE_IRQ() __DI()
+#define MG_RH850_ENABLE_IRQ() __EI()
 #else
 #define MG_ARM_DISABLE_IRQ()
 #define MG_ARM_ENABLE_IRQ()
@@ -2676,6 +2679,7 @@ MG_IRAM void mg_ota_boot(void);  // Bootloader function
 #define MG_DEVICE_RT1020 3      // IMXRT1020
 #define MG_DEVICE_RT1060 4      // IMXRT1060
 #define MG_DEVICE_CH32V307 100  // WCH CH32V307
+#define MG_DEVICE_U2A 200       // Renesas U2A16, U2A8, U2A6
 #define MG_DEVICE_CUSTOM 1000   // Custom implementation
 
 #ifndef MG_DEVICE
diff --git a/src/device.h b/src/device.h
index c4a7ee88..d90b82da 100644
--- a/src/device.h
+++ b/src/device.h
@@ -11,6 +11,7 @@
 #define MG_DEVICE_RT1020 3      // IMXRT1020
 #define MG_DEVICE_RT1060 4      // IMXRT1060
 #define MG_DEVICE_CH32V307 100  // WCH CH32V307
+#define MG_DEVICE_U2A 200       // Renesas U2A16, U2A8, U2A6
 #define MG_DEVICE_CUSTOM 1000   // Custom implementation
 
 #ifndef MG_DEVICE
diff --git a/src/device_imxrt.c b/src/device_imxrt.c
index f1b2b9e2..9571b136 100644
--- a/src/device_imxrt.c
+++ b/src/device_imxrt.c
@@ -249,7 +249,7 @@ MG_IRAM bool mg_flash_erase(void *addr) {
   return ok;
 }
 
-MG_IRAM bool mg_flash_swap_bank() {
+MG_IRAM bool mg_flash_swap_bank(void) {
   return true;
 }
 
diff --git a/src/device_stm32h7.c b/src/device_stm32h7.c
index fe40232a..e3f7c777 100644
--- a/src/device_stm32h7.c
+++ b/src/device_stm32h7.c
@@ -104,7 +104,7 @@ MG_IRAM bool mg_flash_erase(void *addr) {
   return ok;
 }
 
-MG_IRAM bool mg_flash_swap_bank() {
+MG_IRAM bool mg_flash_swap_bank(void) {
   if (mg_flash_bank() == 0) return true;
   uint32_t bank = FLASH_BASE1;
   uint32_t desired = flash_bank_is_swapped(bank) ? 0 : MG_BIT(31);
diff --git a/src/util.h b/src/util.h
index 0b2bb49a..7f2ba359 100644
--- a/src/util.h
+++ b/src/util.h
@@ -23,9 +23,9 @@ uint64_t mg_now(void);     // Return milliseconds since Epoch
 #define mg_htons(x) mg_ntohs(x)
 #define mg_htonl(x) mg_ntohl(x)
 
-#define MG_U32(a, b, c, d)                                         \
-  (((uint32_t) ((a) &255) << 24) | ((uint32_t) ((b) &255) << 16) | \
-   ((uint32_t) ((c) &255) << 8) | (uint32_t) ((d) &255))
+#define MG_U32(a, b, c, d)                                           \
+  (((uint32_t) ((a) & 255) << 24) | ((uint32_t) ((b) & 255) << 16) | \
+   ((uint32_t) ((c) & 255) << 8) | (uint32_t) ((d) & 255))
 
 // For printing IPv4 addresses: printf("%d.%d.%d.%d\n", MG_IPADDR_PARTS(&ip))
 #define MG_U8P(ADDR) ((uint8_t *) (ADDR))
@@ -39,9 +39,12 @@ uint64_t mg_now(void);     // Return milliseconds since Epoch
 #define MG_ROUND_UP(x, a) ((a) == 0 ? (x) : ((((x) + (a) -1) / (a)) * (a)))
 #define MG_ROUND_DOWN(x, a) ((a) == 0 ? (x) : (((x) / (a)) * (a)))
 
-#ifdef __GNUC__
+#if defined(__GNUC__)
 #define MG_ARM_DISABLE_IRQ() asm volatile("cpsid i" : : : "memory")
 #define MG_ARM_ENABLE_IRQ() asm volatile("cpsie i" : : : "memory")
+#elif defined(__CCRH__)
+#define MG_RH850_DISABLE_IRQ() __DI()
+#define MG_RH850_ENABLE_IRQ() __EI()
 #else
 #define MG_ARM_DISABLE_IRQ()
 #define MG_ARM_ENABLE_IRQ()