MLECO-2395: Allow users to select Ethos-U memory mode

Change-Id: Icf09410f12072e8d7850dd1e540c3243af24ed09
diff --git a/source/application/hal/platforms/bare-metal/bsp/mem_layout/mps3-sse-300.ld b/source/application/hal/platforms/bare-metal/bsp/mem_layout/mps3-sse-300.ld
index e5c2a14..bcbc81f 100644
--- a/source/application/hal/platforms/bare-metal/bsp/mem_layout/mps3-sse-300.ld
+++ b/source/application/hal/platforms/bare-metal/bsp/mem_layout/mps3-sse-300.ld
@@ -144,7 +144,11 @@
   .sram :
   {
     . = ALIGN(16);
-    *(.bss.NoInit.activation_buf)
+    /* Cache area (if used) */
+    *(.bss.NoInit.ethos_u_cache)
+    . = ALIGN (16);
+    /* activation buffers a.k.a tensor arena when memory mode sram only or shared sram */
+    *(.bss.NoInit.activation_buf_sram)
     . = ALIGN(16);
   } > SRAM AT > SRAM
 
@@ -177,13 +181,17 @@
     /* __attribute__((aligned(16))) is not handled by the CMSIS startup code.
      * Force the alignment here as a workaround */
     . = ALIGN(16);
+    /* nn model's baked in input matrices */
     *(ifm)
     . = ALIGN(16);
+    /* nn model's default space */
     *(nn_model)
     . = ALIGN (16);
+    /* labels */
     *(labels)
     . = ALIGN (16);
-    *(activation_buf)
+    /* activation buffers a.k.a tensor arena when memory mode dedicated sram */
+    *(activation_buf_dram)
     . = ALIGN (16);
   } > DDR AT > DDR
 
diff --git a/source/application/hal/platforms/bare-metal/bsp/mem_layout/mps3-sse-300.sct b/source/application/hal/platforms/bare-metal/bsp/mem_layout/mps3-sse-300.sct
index 4760875..62dbbe5 100644
--- a/source/application/hal/platforms/bare-metal/bsp/mem_layout/mps3-sse-300.sct
+++ b/source/application/hal/platforms/bare-metal/bsp/mem_layout/mps3-sse-300.sct
@@ -67,8 +67,11 @@
     ;-----------------------------------------------------
     isram.bin       0x31000000  UNINIT ALIGN 16 0x00400000
     {
-        ; activation buffers a.k.a tensor arena
-        *.o (.bss.NoInit.activation_buf)
+        ; Cache area (if used)
+        *.o (.bss.NoInit.ethos_u_cache)
+
+        ; activation buffers a.k.a tensor arena when memory mode sram only or shared sram
+        *.o (.bss.NoInit.activation_buf_sram)
     }
 }
 
@@ -88,15 +91,14 @@
         ; nn model's baked in input matrices
         *.o (ifm)
 
-        ; nn model
+        ; nn model's default space
         *.o (nn_model)
 
         ; labels
         *.o (labels)
 
-        ; if the activation buffer (tensor arena) doesn't
-        ; fit in the SRAM region, we accommodate it here
-        *.o (activation_buf)
+        ; activation buffers a.k.a tensor arena when memory mode dedicated sram
+        *.o (activation_buf_dram)
     }
 
     ;-----------------------------------------------------
diff --git a/source/application/hal/platforms/bare-metal/bsp/mem_layout/simple_platform.ld b/source/application/hal/platforms/bare-metal/bsp/mem_layout/simple_platform.ld
index ceaff7d..e5b6bd9 100644
--- a/source/application/hal/platforms/bare-metal/bsp/mem_layout/simple_platform.ld
+++ b/source/application/hal/platforms/bare-metal/bsp/mem_layout/simple_platform.ld
@@ -137,7 +137,11 @@
   .sram :
   {
     . = ALIGN(16);
-    *(.bss.NoInit.activation_buf)
+    /* Cache area (if used) */
+    *(.bss.NoInit.ethos_u_cache)
+    . = ALIGN (16);
+    /* activation buffers a.k.a tensor arena when memory mode sram only or shared sram */
+    *(.bss.NoInit.activation_buf_sram)
     . = ALIGN(16);
   } > SRAM AT > SRAM
 
@@ -170,13 +174,17 @@
     /* __attribute__((aligned(16))) is not handled by the CMSIS startup code.
      * Force the alignment here as a workaround */
     . = ALIGN(16);
+    /* nn model's baked in input matrices */
     *(ifm)
     . = ALIGN(16);
+    /* nn model's default space */
     *(nn_model)
     . = ALIGN (16);
+    /* labels */
     *(labels)
     . = ALIGN (16);
-    *(activation_buf)
+    /* activation buffers a.k.a tensor arena when memory mode dedicated sram */
+    *(activation_buf_dram)
     . = ALIGN (16);
   } > DDR AT > DDR
 
diff --git a/source/application/hal/platforms/bare-metal/bsp/mem_layout/simple_platform.sct b/source/application/hal/platforms/bare-metal/bsp/mem_layout/simple_platform.sct
index 0c6a388..e84d81e 100644
--- a/source/application/hal/platforms/bare-metal/bsp/mem_layout/simple_platform.sct
+++ b/source/application/hal/platforms/bare-metal/bsp/mem_layout/simple_platform.sct
@@ -16,6 +16,10 @@
 ; *************************************************************
 ; ***       Scatter-Loading Description File                ***
 ; *************************************************************
+; Please see docs/sections/appendix.md for memory mapping information.
+;
+; Note: Ethos-U NPU can access BRAM, internal SRAM and the DDR sections => activation buffers and
+;       the model should only be placed in those regions.
 ;
 ;---------------------------------------------------------
 ; First load region (ITCM)
@@ -63,8 +67,11 @@
     ;-----------------------------------------------------
     isram.bin       0x31000000  UNINIT ALIGN 16 0x00400000
     {
-        ; activation buffers a.k.a tensor arena
-        *.o (.bss.NoInit.activation_buf)
+        ; Cache area (if used)
+        *.o (.bss.NoInit.ethos_u_cache)
+
+        ; activation buffers a.k.a tensor arena when memory mode sram only or shared sram
+        *.o (.bss.NoInit.activation_buf_sram)
     }
 }
 
@@ -84,15 +91,14 @@
         ; nn model's baked in input matrices
         *.o (ifm)
 
-        ; nn model
+        ; nn model's default space
         *.o (nn_model)
 
         ; labels
         *.o (labels)
 
-        ; if the activation buffer (tensor arena) doesn't
-        ; fit in the SRAM region, we accommodate it here
-        *.o (activation_buf)
+        ; activation buffers a.k.a tensor arena when memory mode dedicated sram
+        *.o (activation_buf_dram)
     }
 
     ;-----------------------------------------------------