diff --git a/platforms/nuttx/src/bootloader/common/bl.h b/platforms/nuttx/src/bootloader/common/bl.h
index c4ebf588fa..48a11cf4d8 100644
--- a/platforms/nuttx/src/bootloader/common/bl.h
+++ b/platforms/nuttx/src/bootloader/common/bl.h
@@ -106,10 +106,10 @@ extern uint32_t board_get_devices(void);
 extern void clock_deinit(void);
 extern uint32_t flash_func_sector_size(unsigned sector);
 extern void flash_func_erase_sector(unsigned sector);
-extern void flash_func_write_word(uint32_t address, uint32_t word);
-extern uint32_t flash_func_read_word(uint32_t address);
-extern uint32_t flash_func_read_otp(uint32_t address);
-extern uint32_t flash_func_read_sn(uint32_t address);
+extern void flash_func_write_word(uintptr_t address, uint32_t word);
+extern uint32_t flash_func_read_word(uintptr_t address);
+extern uint32_t flash_func_read_otp(uintptr_t address);
+extern uint32_t flash_func_read_sn(uintptr_t address);
 extern void arch_flash_lock(void);
 extern void arch_flash_unlock(void);
 extern void arch_setvtor(const uint32_t *address);
diff --git a/platforms/nuttx/src/bootloader/common/lib/flash_cache.c b/platforms/nuttx/src/bootloader/common/lib/flash_cache.c
index 2c83bb124a..ad3e228b83 100644
--- a/platforms/nuttx/src/bootloader/common/lib/flash_cache.c
+++ b/platforms/nuttx/src/bootloader/common/lib/flash_cache.c
@@ -38,7 +38,7 @@
 
 #include <nuttx/progmem.h>
 
-extern ssize_t arch_flash_write(size_t address, const void *buffer, size_t buflen);
+extern ssize_t arch_flash_write(uintptr_t address, const void *buffer, size_t buflen);
 
 flash_cache_line_t flash_cache[FC_NUMBER_LINES];
 
@@ -57,7 +57,7 @@ inline void fc_reset(void)
 	flash_cache[0].start_address = APP_LOAD_ADDRESS;
 }
 
-static inline flash_cache_line_t *fc_line_select(uint32_t address)
+static inline flash_cache_line_t *fc_line_select(uintptr_t address)
 {
 	for (unsigned w = 0; w < FC_NUMBER_LINES; w++) {
 		if (flash_cache[w].start_address == (address & FC_ADDRESS_MASK)) {
@@ -86,7 +86,7 @@ int fc_flush(flash_cache_line_t *fl)
 	return rv;
 }
 
-int fc_write(uint32_t address, uint32_t word)
+int fc_write(uintptr_t address, uint32_t word)
 {
 	flash_cache_line_t *fc = fc_line_select(address);
 	flash_cache_line_t *fc1 = &flash_cache[1];
@@ -129,7 +129,7 @@ int fc_write(uint32_t address, uint32_t word)
 	return rv;
 }
 
-uint32_t fc_read(uint32_t address)
+uint32_t fc_read(uintptr_t address)
 {
 	// Assume a cache miss read from FLASH memory
 
diff --git a/platforms/nuttx/src/bootloader/common/lib/flash_cache.h b/platforms/nuttx/src/bootloader/common/lib/flash_cache.h
index de180e8792..db5a1bd5ad 100644
--- a/platforms/nuttx/src/bootloader/common/lib/flash_cache.h
+++ b/platforms/nuttx/src/bootloader/common/lib/flash_cache.h
@@ -58,12 +58,12 @@
 // Cache line
 typedef struct flash_cache_line_t {
 	uint32_t index;                   // Index of word written
-	uint32_t start_address;           // cache tag (address in FLASH this is buffering)
+	uintptr_t start_address;          // cache tag (address in FLASH this is buffering)
 	uint32_t words[FC_NUMBER_WORDS];  // Buffered data
 } flash_cache_line_t;
 
 // Resets the cache - all lines flashed and cache_line[0] start_address == APP_LOAD_ADDRESS
 void fc_reset(void);
 // Cache operations
-uint32_t fc_read(uint32_t address);
-int fc_write(uint32_t address, uint32_t word);
+uint32_t fc_read(uintptr_t address);
+int fc_write(uintptr_t address, uint32_t word);
diff --git a/platforms/nuttx/src/bootloader/stm/stm32_common/main.c b/platforms/nuttx/src/bootloader/stm/stm32_common/main.c
index aa696831cc..894834f078 100644
--- a/platforms/nuttx/src/bootloader/stm/stm32_common/main.c
+++ b/platforms/nuttx/src/bootloader/stm/stm32_common/main.c
@@ -437,7 +437,7 @@ void arch_flash_unlock(void)
 	stm32h7_flash_unlock(STM32_FLASH_BANK2);
 }
 
-ssize_t arch_flash_write(size_t address, const void *buffer, size_t buflen)
+ssize_t arch_flash_write(uintptr_t address, const void *buffer, size_t buflen)
 {
 	return up_progmem_write(address, buffer, buflen);
 }
@@ -475,13 +475,13 @@ flash_func_erase_sector(unsigned sector)
 }
 
 void
-flash_func_write_word(uint32_t address, uint32_t word)
+flash_func_write_word(uintptr_t address, uint32_t word)
 {
 	address += APP_LOAD_ADDRESS;
 	fc_write(address, word);
 }
 
-uint32_t flash_func_read_word(uint32_t address)
+uint32_t flash_func_read_word(uintptr_t address)
 {
 
 	if (address & 3) {
@@ -494,7 +494,7 @@ uint32_t flash_func_read_word(uint32_t address)
 
 
 uint32_t
-flash_func_read_otp(uint32_t address)
+flash_func_read_otp(uintptr_t address)
 {
 	return 0;
 }
@@ -550,7 +550,7 @@ int check_silicon(void)
 }
 
 uint32_t
-flash_func_read_sn(uint32_t address)
+flash_func_read_sn(uintptr_t address)
 {
 	// read a byte out from unique chip ID area
 	// it's 12 bytes, or 3 words.