Keil Logo Arm Logo

Technical Support

On-Line Manuals

Linker User Guide

Conventions and feedback Overview of the linker Linking models supported by armlink Image structure and generation Using linker optimizations Getting information about images Accessing and managing symbols with armlink Using scatter files About scatter-loading When to use scatter-loading Scatter-loading command-line option Images with a simple memory map Images with a complex memory map Linker-defined symbols that are not defined when s Specifying stack and heap using the scatter file What is a root region? Creating root execution regions Using the FIXED attribute to create root regions Placing functions and data at specific addresses Placing a named section explicitly using scatter-l Placing unassigned sections with the .ANY module s Examples of using placement algorithms for .ANY se Example of next_fit algorithm showing behavior of Examples of using sorting algorithms for .ANY sect Selecting veneer input sections in scatter-loading Using __attribute__((section("name"))) t Using __at sections to place sections at a specifi Restrictions on placing __at sections Automatic placement of __at sections Manual placement of __at sections Placing a key in flash memory using __at Placing a structure over a peripheral register usi Placement of sections with overlays About placing ARM C and C++ library code Example of placing code in a root region Example of placing ARM C library code Example of placing ARM C++ library code Example of placing ARM library helper functions Reserving an empty region About creating regions on page boundaries Overalignment of execution regions and input secti Using preprocessing commands in a scatter file Expression evaluation in scatter files Using expression evaluation in a scatter file to a Equivalent scatter-loading descriptions for simple Type 1 image, one load region and contiguous execu Type 2 image, one load region and non-contiguous e Type 3 image, two load regions and non-contiguous Scatter file to ELF mapping

Linker User Guide

Images with a simple memory map

Images with a simple memory map

If an image has a simple memory map, you can either:

  • use a scatter file

  • specify the memory map using basic linker command-line options.

The following figure shows a simple memory map:

Figure 6. Simple scatter-loaded memory map


The following example shows the corresponding scatter-loading description that loads the segments from the object file into memory:

Example 10. Simple memory map in a scatter file

LOAD_ROM 0x0000 0x8000       ; Name of load region (LOAD_ROM),
                             ; Start address for load region (0x0000),
                             ; Maximum size of load region (0x8000)
{
    EXEC_ROM 0x0000 0x8000   ; Name of first exec region (EXEC_ROM),
                             ; Start address for exec region (0x0000),
                             ; Maximum size of first exec region (0x8000)
    {
        * (+RO)              ; Place all code and RO data into
                             ; this exec region
    }

    SRAM 0x10000 0x6000      ; Name of second exec region (RAM),
                             ; Start address of second exec region (0x10000),
                             ; Maximum size of second exec region (0x6000)
    {
        * (+RW, +ZI)         ; Place all RW and ZI data into
                             ; this exec region
    }
}

The maximum size specifications for the regions are optional. However, if you include them, they enable the linker to check that a region does not overflow its boundary.

In this example, you can achieve the same result, apart from the limit checking with the following linker command-line:

armlink --ro_base 0x0 --rw_base 0x10000

Copyright © 2007-2008, 2011-2012 ARM. All rights reserved.ARM DUI 0377D
Non-ConfidentialID062912

Keil logo

Arm logo
Important information

This site uses cookies to store information on your computer. By continuing to use our site, you consent to our cookies.