docs: Add HowToConfigureMemory doc and integrate the memory guide in …

…Porting_Guide

HowToConfigureMemory doc has information about memory.
HowToUseMultiHeap guide should be in HowToConfigureMemory doc.

docs/HowToConfigureMemory.md

@@ -0,0 +1,45 @@
+# How to configure Memory
+
+## Contents
+> [Configuration](#configuration)  
+> [Linker Scripts](#linker-scripts)  
+> [Multi-Heap Support](#multi-heap-support)
+
+## Configuration
+There are two configurations to configure memory, CONFIG_RAM_START and CONFIG_RAM_SIZE.  
+Menuconfig helps to change them as shown below:
+```
+cd $TIZENRT_BASEDIR
+cd os
+make menuconfig
+```
+Find configs with following step:
+```
+Hardware Configuration -> Chip selection -> Boot Memory Configuration
+```
+Set CONFIG_RAM_START as hexa value and set CONFIG_RAM_SIZE as decimal value.
+```
+CONFIG_RAM_START=0x02023800
+CONFIG_RAM_SIZE=968704
+```
+Heap allocation will use these values for setting heap start and end address.
+
+## Linker Scripts
+Linker script has RAM start and size information also.  
+file path : *build/configs/<BOARD_NAME>/scripts/<SCRIPTS_NAME>.ld*  
+
+```
+MEMORY
+{
+...
+	SRAM	(rwx)	: ORIGIN = 0x02023800, LENGTH = 946K
+...
+}
+```
+These value should be matched with TizenRT configuration file.
+
+## Multi-Heap Support
+TizenRT can support multi-heap, if there is another RAM partition in H/W with discontinuous address to previous one.  
+Please refer [How to use multiple memory map as a heap](HowToUseMultiHeap.md).
+
+

docs/Porting_Guide.md

@@ -28,7 +28,7 @@ Understanding the TizenRT code structure and adhering to the structure helps in
 1. [How to add new board](HowToAddnewBoard.md)
 2. [How to use peripheral](HowToUsePeripheral.md)
 3. [How to add static library](HowToAddStaticLibrary.md)
-4. [How to use multiple memory as a heap](HowToUseMultiHeap.md)
+4. [How to configure memory](HowToConfigureMemory.md)
 5. [How to use MPU](HowToUseMPU.md)
 
 ## File System