RealView Debugger User Guide - ARM Information Center

Memory Mapping5.1.2 Memory map considerationsWhen working with memory mapping, you must be aware of the following:• The top_of_memory value must be higher than the sum of the program base addressand program size. If set incorrectly, your program might crash because of stackcorruption or because your program overwrites its own code.• There is no requirement that the address specified by top_of_memory is at the truetop of memory. A C or assembler program can use memory at higher addresses.• If you are working with a scatterloaded application, you must define the locationof stack and heap in your code.• The default memory model for RealView ARMulator ® ISS (RVISS) createsmemory pages as required through the whole address space, and, therefore, theRVISS configuration file can specify a value for top of stack that is in highmemory.• When an image is loaded to a debug target, the memory map is checked toconfirm that it is valid to load to the locations specified in the executable program.Memory is loaded and then read back to verify a successful load and to confirmthat genuine memory is present. Memory sections defined as Auto are alsoupdated to reflect the access type specified in the executable image.• By default, RealView Debugger tries to set a software breakpoint. However,where enabled, the memory map determines the type of breakpoint that you canset. For example, only hardware breakpoints can be set in Flash and ROM.• The memory map is used to define how memory contents are color coded whendisplayed in the Memory pane.ARM DUI 0153G Copyright © 2002-2005 ARM Limited. All rights reserved. 5-3