diff --git a/libraries/AP_HAL_ChibiOS/Util.cpp b/libraries/AP_HAL_ChibiOS/Util.cpp
index a640e1c1f4..00cccf7f67 100644
--- a/libraries/AP_HAL_ChibiOS/Util.cpp
+++ b/libraries/AP_HAL_ChibiOS/Util.cpp
@@ -54,7 +54,7 @@ void* Util::malloc_type(size_t size, AP_HAL::Util::Memory_Type mem_type)
     if (mem_type == AP_HAL::Util::MEM_DMA_SAFE) {
         return malloc_dma(size);
     } else if (mem_type == AP_HAL::Util::MEM_FAST) {
-        return try_alloc_from_ccm_ram(size);
+        return malloc_fastmem(size);
     } else {
         return calloc(1, size);
     }
@@ -68,16 +68,6 @@ void Util::free_type(void *ptr, size_t size, AP_HAL::Util::Memory_Type mem_type)
 }
 
 
-void* Util::try_alloc_from_ccm_ram(size_t size)
-{
-    void *ret = malloc_ccm(size);
-    if (ret == nullptr) {
-        //we failed to allocate from CCM so we are going to try common SRAM
-        ret = calloc(1, size);
-    }
-    return ret;
-}
-
 #ifdef ENABLE_HEAP
 
 void *Util::allocate_heap_memory(size_t size)
diff --git a/libraries/AP_HAL_ChibiOS/Util.h b/libraries/AP_HAL_ChibiOS/Util.h
index 4ca934a0dd..bf45451108 100644
--- a/libraries/AP_HAL_ChibiOS/Util.h
+++ b/libraries/AP_HAL_ChibiOS/Util.h
@@ -75,8 +75,6 @@ private:
 
     static ToneAlarmPwmGroup _toneAlarm_pwm_group;
 #endif
-    void* try_alloc_from_ccm_ram(size_t size);
-    uint32_t available_memory_in_ccm_ram(void);
 
 #if HAL_HAVE_IMU_HEATER
     struct {
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/common/malloc.c b/libraries/AP_HAL_ChibiOS/hwdef/common/malloc.c
index f986b8e04d..5e9fd46509 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/common/malloc.c
+++ b/libraries/AP_HAL_ChibiOS/hwdef/common/malloc.c
@@ -31,6 +31,20 @@
 #include <stdarg.h>
 #include "stm32_util.h"
 
+#define MEM_REGION_FLAG_DMA_OK 1
+#define MEM_REGION_FLAG_FAST   2
+
+static struct memory_region {
+    void *address;
+    uint32_t size;
+    uint32_t flags;
+    memory_heap_t heap;
+} memory_regions[] = { HAL_MEMORY_REGIONS };
+
+// the first memory region is already setup as the ChibiOS
+// default heap, so we will index from 1 in the allocators
+#define NUM_MEMORY_REGIONS (sizeof(memory_regions)/sizeof(memory_regions[0]))
+
 #if CH_CFG_USE_HEAP == TRUE
 
 #define MIN_ALIGNMENT 8
@@ -41,18 +55,6 @@
 #define DMA_ALIGNMENT 8
 #endif
 
-#ifdef HAL_NO_CCM
-#undef CCM_RAM_SIZE_KB
-#endif
-
-#if defined(CCM_RAM_SIZE_KB)
-static memory_heap_t ccm_heap;
-#endif
-
-#if defined(DTCM_RAM_SIZE_KB)
-static memory_heap_t dtcm_heap;
-#endif
-
 // size of memory reserved for dma-capable alloc
 #ifndef DMA_RESERVE_SIZE
 #define DMA_RESERVE_SIZE 4096
@@ -62,96 +64,102 @@ static memory_heap_t dtcm_heap;
 static memory_heap_t dma_reserve_heap;
 #endif
 
-static void *malloc_dtcm(size_t size);
-
 /*
   initialise memory handling
  */
 void malloc_init(void)
 {
-#if defined(CCM_RAM_SIZE_KB)
-    chHeapObjectInit(&ccm_heap, (void *)CCM_BASE_ADDRESS, CCM_RAM_SIZE_KB*1024);
-#endif
-
-#if defined(DTCM_RAM_SIZE_KB)
-    chHeapObjectInit(&dtcm_heap, (void *)DTCM_BASE_ADDRESS, DTCM_RAM_SIZE_KB*1024);
-#endif
+    for (uint8_t i=1; i<NUM_MEMORY_REGIONS; i++) {
+        chHeapObjectInit(&memory_regions[i].heap, memory_regions[i].address, memory_regions[i].size);
+    }
 
 #if DMA_RESERVE_SIZE != 0
     /*
       create a DMA reserve heap, to ensure we keep some memory for DMA
       safe memory allocations
      */
-    void *dma_reserve = malloc_dtcm(DMA_RESERVE_SIZE);
-    if (!dma_reserve) {
-        dma_reserve = chHeapAllocAligned(NULL, DMA_RESERVE_SIZE, MIN_ALIGNMENT);
-    }
+    void *dma_reserve = malloc_dma(DMA_RESERVE_SIZE);
+    osalDbgAssert(dma_reserve != NULL, "DMA reserve");
     chHeapObjectInit(&dma_reserve_heap, dma_reserve, DMA_RESERVE_SIZE);
-#endif //#if DMA_RESERVE_SIZE != 0
-}
-
-void *malloc_ccm(size_t size)
-{
-    void *p = NULL;
-#if defined(CCM_RAM_SIZE_KB)
-    p = chHeapAllocAligned(&ccm_heap, size, CH_HEAP_ALIGNMENT);
-    if (p != NULL) {
-        memset(p, 0, size);
-    }
-#else
-    (void)size;
 #endif
-    return p;
 }
 
-static void *malloc_dtcm(size_t size)
-{
-    void *p = NULL;
-#if defined(DTCM_RAM_SIZE_KB)
-    p = chHeapAllocAligned(&dtcm_heap, size, DMA_ALIGNMENT);
-#else
-    (void)size;
-#endif
-    if (p != NULL) {
-        memset(p, 0, size);
-    }
-    return p;
-}
-
-void *malloc(size_t size)
+static void *malloc_flags(size_t size, uint32_t flags)
 {
     if (size == 0) {
         return NULL;
     }
-    void *p = chHeapAllocAligned(NULL, size, MIN_ALIGNMENT);
-    if (p) {
-        memset(p, 0, size);
-        return p;
+    const uint8_t alignment = (flags&MEM_REGION_FLAG_DMA_OK?DMA_ALIGNMENT:MIN_ALIGNMENT);
+    void *p = NULL;
+
+    if (flags & MEM_REGION_FLAG_DMA_OK) {
+        // allocate multiple of DMA alignment
+        size = (size + (DMA_ALIGNMENT-1)) & ~(DMA_ALIGNMENT-1);
     }
-    if (!p) {
-        // fall back to CCM memory
-        p = malloc_ccm(size);
+
+    // if no flags are set or this is a DMA request and default heap
+    // is DMA safe then start with default heap
+    if (flags == 0 || (flags == MEM_REGION_FLAG_DMA_OK &&
+                       (memory_regions[0].flags & MEM_REGION_FLAG_DMA_OK))) {
+        p = chHeapAllocAligned(NULL, size, alignment);
         if (p) {
-            return p;
+            goto found;
         }
     }
-    if (!p) {
-        // fall back to DTCM memory
-        p = malloc_dtcm(size);
+
+    // try with matching flags
+    for (uint8_t i=1; i<NUM_MEMORY_REGIONS; i++) {
+        if ((flags & MEM_REGION_FLAG_DMA_OK) &&
+            !(memory_regions[i].flags & MEM_REGION_FLAG_DMA_OK)) {
+            continue;
+        }
+        if ((flags & MEM_REGION_FLAG_FAST) &&
+            !(memory_regions[i].flags & MEM_REGION_FLAG_FAST)) {
+            continue;
+        }
+        p = chHeapAllocAligned(&memory_regions[i].heap, size, alignment);
         if (p) {
-            return p;
+            goto found;
+        }
+    }
+
+    // if this is a not a DMA request then we can fall back to any heap
+    if (!(flags & MEM_REGION_FLAG_DMA_OK)) {
+        for (uint8_t i=1; i<NUM_MEMORY_REGIONS; i++) {
+            p = chHeapAllocAligned(&memory_regions[i].heap, size, alignment);
+            if (p) {
+                goto found;
+            }
+        }
+        // try default heap
+        p = chHeapAllocAligned(NULL, size, alignment);
+        if (p) {
+            goto found;
         }
     }
 
 #if DMA_RESERVE_SIZE != 0
     // fall back to DMA reserve
-    p = chHeapAllocAligned(&dma_reserve_heap, size, MIN_ALIGNMENT);
+    p = chHeapAllocAligned(&dma_reserve_heap, size, alignment);
     if (p) {
         memset(p, 0, size);
         return p;
     }
 #endif
+
+    // failed
     return NULL;
+
+found:
+    memset(p, 0, size);
+    return p;
+}
+/*
+  allocate normal memory
+ */
+void *malloc(size_t size)
+{
+    return malloc_flags(size, 0);
 }
 
 /*
@@ -159,27 +167,15 @@ void *malloc(size_t size)
  */
 void *malloc_dma(size_t size)
 {
-#if defined(STM32H7)
-    size = (size + (DMA_ALIGNMENT-1)) & ~(DMA_ALIGNMENT-1);
-#endif
-    void *p;
-#if defined(DTCM_RAM_SIZE_KB)
-    p = malloc_dtcm(size);
-#else
-    // if we don't have DTCM memory then assume that main heap is DMA-safe
-    p = chHeapAllocAligned(NULL, size, DMA_ALIGNMENT);
-#endif
-#if DMA_RESERVE_SIZE != 0
-    if (p == NULL) {
-        p = chHeapAllocAligned(&dma_reserve_heap, size, DMA_ALIGNMENT);
-    }
-#endif
+    return malloc_flags(size, MEM_REGION_FLAG_DMA_OK);
+}
 
-    if (p) {
-        memset(p, 0, size);
-    }
-    osalDbgAssert((((uint32_t)p) & (DMA_ALIGNMENT-1)) == 0, "DMA alignment");
-    return p;
+/*
+  allocate fast memory
+ */
+void *malloc_fastmem(size_t size)
+{
+    return malloc_flags(size, MEM_REGION_FLAG_FAST);
 }
 
 void *calloc(size_t nmemb, size_t size)
@@ -200,31 +196,39 @@ void free(void *ptr)
 size_t mem_available(void)
 {
     size_t totalp = 0;
+
     // get memory available on main heap
     chHeapStatus(NULL, &totalp, NULL);
 
     // we also need to add in memory that is not yet allocated to the heap
     totalp += chCoreGetStatusX();
 
-#if defined(CCM_RAM_SIZE_KB)
-    size_t ccm_available = 0;
-    chHeapStatus(&ccm_heap, &ccm_available, NULL);
-    totalp += ccm_available;
-#endif
-
-#if defined(DTCM_RAM_SIZE_KB)
-    size_t dtcm_available = 0;
-    chHeapStatus(&dtcm_heap, &dtcm_available, NULL);
-    totalp += dtcm_available;
-#endif
+    // now our own heaps
+    for (uint8_t i=1; i<NUM_MEMORY_REGIONS; i++) {
+        size_t available = 0;
+        chHeapStatus(&memory_regions[i].heap, &available, NULL);
+        totalp += available;
+    }
 
 #if DMA_RESERVE_SIZE != 0
-    size_t reserve_available = 0;
-    chHeapStatus(&dma_reserve_heap, &reserve_available, NULL);
-    totalp += reserve_available;
+    // and reserve DMA heap
+    size_t available = 0;
+    chHeapStatus(&dma_reserve_heap, &available, NULL);
+    totalp += available;
 #endif
 
     return totalp;
 }
 
 #endif // CH_CFG_USE_HEAP
+
+
+/*
+  flush all memory. Used in chSysHalt()
+ */
+void memory_flush_all(void)
+{
+    for (uint8_t i=0; i<NUM_MEMORY_REGIONS; i++) {
+        cacheBufferFlush(memory_regions[i].address, memory_regions[i].size);
+    }
+}
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/common/stm32_util.c b/libraries/AP_HAL_ChibiOS/hwdef/common/stm32_util.c
index d09c9cc705..dc0fe74945 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/common/stm32_util.c
+++ b/libraries/AP_HAL_ChibiOS/hwdef/common/stm32_util.c
@@ -95,14 +95,6 @@ void show_stack_usage(void)
 }
 #endif
 
-/*
-  flush all memory. Used in chSysHalt()
- */
-void memory_flush_all(void)
-{
-    cacheBufferFlush(HAL_RAM_BASE_ADDRESS, HAL_RAM_SIZE_KB * 1024U);
-}
-
 /*
   set the utc time
  */
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/common/stm32_util.h b/libraries/AP_HAL_ChibiOS/hwdef/common/stm32_util.h
index 671496d9ad..c575071b0b 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/common/stm32_util.h
+++ b/libraries/AP_HAL_ChibiOS/hwdef/common/stm32_util.h
@@ -30,8 +30,8 @@ void show_stack_usage(void);
 
 // allocation functions in malloc.c    
 size_t mem_available(void);
-void *malloc_ccm(size_t size);
 void *malloc_dma(size_t size);
+void *malloc_fastmem(size_t size);
 
 // flush all dcache
 void memory_flush_all(void);
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F100xB.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F100xB.py
index 18c06de471..7a5aa06111 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F100xB.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F100xB.py
@@ -25,12 +25,12 @@ mcu = {
     # location of MCU serial number
     'UDID_START' : 0x1FFFF7E8,
 
-    # base address of main memory
-    'RAM_BASE_ADDRESS' : 0x20000000,
-
-    # size of main memory
-    'RAM_SIZE_KB' : 8, 
-    
+    # ram map, as list of (address, size-kb, flags)
+    # flags of 1 means DMA-capable
+    # flags of 2 means faster memory for CPU intensive work
+    'RAM_MAP' : [
+        (0x20000000, 8, 1), # main memory, DMA safe
+    ]
 }
 
 ADC1_map = {
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F405xx.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F405xx.py
index c85bb56b6e..9c98c31a11 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F405xx.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F405xx.py
@@ -15,15 +15,13 @@ mcu = {
     # location of MCU serial number
     'UDID_START' : 0x1FFF7A10,
 
-    # base address of main memory
-    'RAM_BASE_ADDRESS' : 0x20000000,
-
-    # size of main memory
-    'RAM_SIZE_KB' : 128,
-
-    # CCM ram address and size
-    'CCM_BASE_ADDRESS' : 0x10000000,
-    'CCM_RAM_SIZE_KB' : 64,
+    # ram map, as list of (address, size-kb, flags)
+    # flags of 1 means DMA-capable
+    # flags of 2 means faster memory for CPU intensive work
+    'RAM_MAP' : [
+        (0x20000000, 128, 1), # main memory, DMA safe
+        (0x10000000,  64, 2), # CCM memory, faster, but not DMA safe
+    ]
 }
 
 AltFunction_map = {
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F407xx.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F407xx.py
index e4c940ec72..3bfad17e19 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F407xx.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F407xx.py
@@ -15,15 +15,13 @@ mcu = {
     # location of MCU serial number
     'UDID_START' : 0x1FFF7A10,
 
-    # base address of main memory
-    'RAM_BASE_ADDRESS' : 0x20000000,
-
-    # size of main memory
-    'RAM_SIZE_KB' : 128,
-
-    # CCM ram address and size
-    'CCM_BASE_ADDRESS' : 0x10000000,
-    'CCM_RAM_SIZE_KB' : 64,
+    # ram map, as list of (address, size-kb, flags)
+    # flags of 1 means DMA-capable
+    # flags of 2 means faster memory for CPU intensive work
+    'RAM_MAP' : [
+        (0x20000000, 128, 1), # main memory, DMA safe
+        (0x10000000,  64, 2), # CCM memory, faster, but not DMA safe
+    ]
 }
 
 DMA_Map = {
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F412Rx.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F412Rx.py
index 15d2b6fae8..38772d3fe8 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F412Rx.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F412Rx.py
@@ -15,11 +15,12 @@ mcu = {
     # location of MCU serial number
     'UDID_START' : 0x1FFF7A10,
 
-    # base address of main memory
-    'RAM_BASE_ADDRESS' : 0x20000000,
-
-    # size of main memory
-    'RAM_SIZE_KB' : 256
+    # ram map, as list of (address, size-kb, flags)
+    # flags of 1 means DMA-capable
+    # flags of 2 means faster memory for CPU intensive work
+    'RAM_MAP' : [
+        (0x20000000, 256, 1), # main memory, DMA safe
+    ]
 }
 
 DMA_Map = {
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F427xx.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F427xx.py
index 17f6f66fd4..3c2f1c9f1b 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F427xx.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F427xx.py
@@ -15,15 +15,13 @@ mcu = {
     # location of MCU serial number
     'UDID_START' : 0x1FFF7A10,
 
-    # base address of main memory
-    'RAM_BASE_ADDRESS' : 0x20000000,
-
-    # size of main memory
-    'RAM_SIZE_KB' : 192,
-
-    # CCM ram address and size
-    'CCM_BASE_ADDRESS' : 0x10000000,
-    'CCM_RAM_SIZE_KB' : 64,
+    # ram map, as list of (address, size-kb, flags)
+    # flags of 1 means DMA-capable
+    # flags of 2 means faster memory for CPU intensive work
+    'RAM_MAP' : [
+        (0x20000000, 192, 1), # main memory, DMA safe
+        (0x10000000,  64, 2), # CCM memory, faster, but not DMA safe
+    ]
 }
 
 DMA_Map = {
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F469xx.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F469xx.py
index fa06405150..fc4f3e5432 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F469xx.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F469xx.py
@@ -28,15 +28,13 @@ mcu = {
     # location of MCU serial number
     'UDID_START' : 0x1FFF7A10,
 
-    # base address of main memory
-    'RAM_BASE_ADDRESS' : 0x20000000,
-
-    # size of main memory
-    'RAM_SIZE_KB' : 320,
-
-    # CCM ram address and size
-    'CCM_BASE_ADDRESS' : 0x10000000,
-    'CCM_RAM_SIZE_KB' : 64,
+    # ram map, as list of (address, size-kb, flags)
+    # flags of 1 means DMA-capable
+    # flags of 2 means faster memory for CPU intensive work
+    'RAM_MAP' : [
+        (0x20000000, 320, 1), # main memory, DMA safe
+        (0x10000000,  64, 1), # CCM memory, faster, not DMA safe
+    ]
 }
 
 DMA_Map = {
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F745xx.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F745xx.py
index ec47cca401..1a5496147c 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F745xx.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F745xx.py
@@ -15,17 +15,13 @@ mcu = {
     # location of MCU serial number
     'UDID_START' : 0x1FF0F420,
 
-    # base address of main memory. We use SRAM1/SRAM2 as main memory
-    # for maximum speed (using the dcache). DMA will be done from DTCM
-    # memory
-    'RAM_BASE_ADDRESS' : 0x20010000,
-
-    # size of main memory
-    'RAM_SIZE_KB' : 256,
-
-    # DTCM ram address and size
-    'DTCM_BASE_ADDRESS' : 0x20000000,
-    'DTCM_RAM_SIZE_KB' : 64,
+    # ram map, as list of (address, size-kb, flags)
+    # flags of 1 means DMA-capable
+    # flags of 2 means faster memory for CPU intensive work
+    'RAM_MAP' : [
+        (0x20010000, 256, 0), # main memory, not DMA safe
+        (0x20000000,  64, 1), # DTCM memory, DMA safe
+    ]
 }
 
 DMA_Map = {
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F767xx.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F767xx.py
index 4aa606b91d..3ffd235f28 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F767xx.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F767xx.py
@@ -30,17 +30,13 @@ mcu = {
     # location of MCU serial number
     'UDID_START' : 0x1FF0F420,
 
-    # base address of main memory. We use SRAM1/SRAM2 as main memory
-    # for maximum speed (using the dcache). DMA will be done from DTCM
-    # memory
-    'RAM_BASE_ADDRESS' : 0x20020000,
-
-    # size of main memory
-    'RAM_SIZE_KB' : 384,
-
-    # DTCM ram address and size
-    'DTCM_BASE_ADDRESS' : 0x20000000,
-    'DTCM_RAM_SIZE_KB' : 128,
+    # ram map, as list of (address, size-kb, flags)
+    # flags of 1 means DMA-capable
+    # flags of 2 means faster memory for CPU intensive work
+    'RAM_MAP' : [
+        (0x20020000, 384, 0), # SRAM1/SRAM2
+        (0x20000000, 128, 1), # DTCM, DMA
+    ]
 }
 
 DMA_Map = {
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F777xx.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F777xx.py
index f160411443..1c5cde06a1 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F777xx.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32F777xx.py
@@ -29,17 +29,13 @@ mcu = {
     # location of MCU serial number
     'UDID_START' : 0x1FF0F420,
 
-    # base address of main memory. We use SRAM1/SRAM2 as main memory
-    # for maximum speed (using the dcache). DMA will be done from DTCM
-    # memory
-    'RAM_BASE_ADDRESS' : 0x20020000,
-
-    # size of main memory
-    'RAM_SIZE_KB' : 384,
-
-    # DTCM ram address and size
-    'DTCM_BASE_ADDRESS' : 0x20000000,
-    'DTCM_RAM_SIZE_KB' : 128,
+    # ram map, as list of (address, size-kb, flags)
+    # flags of 1 means DMA-capable
+    # flags of 2 means faster memory for CPU intensive work
+    'RAM_MAP' : [
+        (0x20020000, 384, 0), # SRAM1/SRAM2
+        (0x20000000, 128, 1), # DTCM, DMA
+    ]
 }
 
 DMA_Map = {
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32H743xx.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32H743xx.py
index 9d08719297..327397b6ac 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32H743xx.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/STM32H743xx.py
@@ -14,17 +14,16 @@ mcu = {
     # location of MCU serial number
     'UDID_START' : 0x1FF1E800,
 
-    # base address of main memory. We use AXI SRAM as main memory
-    # for maximum speed (using the dcache). DMA will be done from DTCM
-    # memory. Other SRAM areas will be added later
-    'RAM_BASE_ADDRESS' : 0x24000000,
-
-    # size of main memory
-    'RAM_SIZE_KB' : 512,
-
-    # DTCM ram address and size
-#    'DTCM_BASE_ADDRESS' : 0x20000000,
-#    'DTCM_RAM_SIZE_KB' : 128,
+    # ram map, as list of (address, size-kb, flags)
+    # flags of 1 means DMA-capable
+    # flags of 2 means faster memory for CPU intensive work
+    'RAM_MAP' : [
+        (0x24000000, 512, 1), # AXI SRAM
+        (0x30000000, 288, 1), # SRAM1, SRAM2, SRAM3
+        (0x38000000,  64, 1), # SRAM4
+        (0x00004000,  63, 2), # ITCM (first 1k removed, to keep address 0 unused)
+        (0x20000000, 128, 2), # DTCM, tightly coupled, no DMA
+    ]
 }
 
 pincount = {
diff --git a/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py b/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
index fdbb1348b2..f04ff98948 100644
--- a/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
+++ b/libraries/AP_HAL_ChibiOS/hwdef/scripts/chibios_hwdef.py
@@ -549,31 +549,18 @@ def write_mcu_config(f):
     f.write('#define BOARD_FLASH_SIZE %u\n' % flash_size)
     f.write('#define CRT1_AREAS_NUMBER 1\n')
 
-    # get core-coupled-memory if available (not be DMA capable)
-    ccm_size = get_mcu_config('CCM_RAM_SIZE_KB')
-    if ccm_size is not None:
-        f.write('\n// core-coupled memory\n')
-        f.write('#define CCM_RAM_SIZE_KB %u\n' % ccm_size)
-        f.write('#define CCM_BASE_ADDRESS 0x%08x\n' % get_mcu_config('CCM_BASE_ADDRESS', True))
-
-    # get DTCM memory if available (DMA-capable with no cache flush/invalidate)
-    dtcm_size = get_mcu_config('DTCM_RAM_SIZE_KB')
-    if dtcm_size is not None:
-        f.write('\n// DTCM memory\n')
-        f.write('#define DTCM_RAM_SIZE_KB %u\n' % dtcm_size)
-        f.write('#define DTCM_BASE_ADDRESS 0x%08x\n' % get_mcu_config('DTCM_BASE_ADDRESS', True))
-        
     flash_reserve_start = get_config(
         'FLASH_RESERVE_START_KB', default=16, type=int)
     f.write('\n// location of loaded firmware\n')
     f.write('#define FLASH_LOAD_ADDRESS 0x%08x\n' % (0x08000000 + flash_reserve_start*1024))
     f.write('\n')
 
-    ram_size_kb = get_mcu_config('RAM_SIZE_KB', True)
-    ram_base_address = get_mcu_config('RAM_BASE_ADDRESS', True)
-    f.write('// main memory size and address\n')
-    f.write('#define HAL_RAM_SIZE_KB %uU\n' % ram_size_kb)
-    f.write('#define HAL_RAM_BASE_ADDRESS 0x%08x\n' % ram_base_address)
+    ram_map = get_mcu_config('RAM_MAP', True)
+    f.write('// memory regions\n')
+    regions = []
+    for (address, size, flags) in ram_map:
+        regions.append('{(void*)0x%08x, 0x%08x, 0x%02x, {}}' % (address, size*1024, flags))
+    f.write('#define HAL_MEMORY_REGIONS %s\n' % ', '.join(regions))
 
     f.write('\n// CPU serial number (12 bytes)\n')
     f.write('#define UDID_START 0x%08x\n\n' % get_mcu_config('UDID_START', True))
@@ -646,9 +633,8 @@ def write_ldscript(fname):
     # space to reserve for storage at end of flash
     flash_reserve_end = get_config('FLASH_RESERVE_END_KB', default=0, type=int)
 
-    # ram size
-    ram_size = get_mcu_config('RAM_SIZE_KB', True)
-    ram_base = get_mcu_config('RAM_BASE_ADDRESS', True)
+    # ram layout
+    ram_map = get_mcu_config('RAM_MAP', True)
 
     flash_base = 0x08000000 + flash_reserve_start * 1024
     flash_length = flash_size - (flash_reserve_start + flash_reserve_end)
@@ -663,7 +649,7 @@ MEMORY
 }
 
 INCLUDE common.ld
-''' % (flash_base, flash_length, ram_base, ram_size))
+''' % (flash_base, flash_length, ram_map[0][0], ram_map[0][1]))
 
 def copy_common_linkerscript(outdir, hwdef):
     dirpath = os.path.dirname(hwdef)