diff --git a/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/board.cmake b/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/board.cmake
index 16cb77ff4..ea9ffacf4 100644
--- a/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/board.cmake
+++ b/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/board.cmake
@@ -1,15 +1,16 @@
 set(MCU_VARIANT stm32h7s3xx)
 set(JLINK_DEVICE stm32h7s3xx)
 
-function(update_board TARGET)
+set(LD_FILE_GNU ${CMAKE_CURRENT_LIST_DIR}/stm32h7s3xx_flash.ld)
+set(LD_FILE_Clang ${LD_FILE_GNU})
+set(LD_FILE_IAR ${CMAKE_CURRENT_LIST_DIR}/stm32h7s3xx_flash.icf)
 
-  set(LD_FILE_GNU ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/stm32h7s3xx_flash.ld)
-  set(LD_FILE_Clang ${LD_FILE_GNU})
-  set(LD_FILE_IAR ${CMAKE_CURRENT_FUNCTION_LIST_DIR}/stm32h7s3xx_flash.icf)
+function(update_board TARGET)
 
   target_compile_definitions(${TARGET} PUBLIC
     STM32H7S3xx
     SEGGER_RTT_SECTION="noncacheable_buffer"
+    BUFFER_SIZE_UP=0x3000
     )
 
   target_sources(${TARGET} PUBLIC
diff --git a/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/board.mk b/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/board.mk
index c802d0211..1946f523c 100644
--- a/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/board.mk
+++ b/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/board.mk
@@ -20,3 +20,4 @@ INC += \
 
 CFLAGS += \
 	-DSEGGER_RTT_SECTION=\"noncacheable_buffer\" \
+	-DBUFFER_SIZE_UP=0x3000 \
diff --git a/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/stm32h7s3xx_flash.icf b/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/stm32h7s3xx_flash.icf
index 17af9a620..8ffaa74a7 100644
--- a/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/stm32h7s3xx_flash.icf
+++ b/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/stm32h7s3xx_flash.icf
@@ -4,7 +4,7 @@
 /*-Specials-*/
 define symbol __ICFEDIT_intvec_start__ = 0x08000000;
 /*-Memory Regions-*/
-define symbol NONCACHEABLEBUFFER_size   = 0x1000;
+define symbol NONCACHEABLEBUFFER_size   = 0x4000;
 define symbol __ICFEDIT_region_ROM_start__ = 0x08000000;
 define symbol __ICFEDIT_region_ROM_end__   = 0x0800FFFF;
 define symbol __ICFEDIT_region_RAM_start__ = 0x24000000;
diff --git a/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/stm32h7s3xx_flash.ld b/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/stm32h7s3xx_flash.ld
index 2c6bb27de..a81763bf9 100644
--- a/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/stm32h7s3xx_flash.ld
+++ b/hw/bsp/stm32h7rs/boards/stm32h7s3nucleo/stm32h7s3xx_flash.ld
@@ -47,7 +47,7 @@ __FLASH_SIZE   = 0x00010000;
 
 __RAM_BEGIN    = 0x24000000;
 __RAM_SIZE     = 0x4FC00;
-__RAM_NONCACHEABLEBUFFER_SIZE = 0x1000;
+__RAM_NONCACHEABLEBUFFER_SIZE = 0x4000;
 
 /* Memories definition */
 MEMORY