ARM Compiler toolchain Using the Linker - ARM Information Center

8.5 Images with a complex memory map
Using scatter files
For images with a complex memory map, you cannot specify the memory map using basic
linker command-line options. Such images require the use of a scatter file.
The following figure shows a complex memory map:
Figure 8-2 Complex memory map
The following example shows the corresponding scatter-loading description that loads the
segments from the program1.o and program2.o files into memory:
Example 8-2 Complex memory map in a scatter file
LOAD_ROM_1 0x0000 ; Start address for first load region (0x0000)
{
EXEC_ROM_1 0x0000 ; Start address for first exec region (0x0000)
{
program1.o (+RO) ; Place all code and RO data from
; program1.o into this exec region
}
}
0x4000
0x0000
Load view
RW section#2
RO section#2
RW section#1
RO section#1
Zero fill
Execution view
ZI section#2
RW section#1
ZI section#1
RW section#2
RO section#2
RO section#1
DRAM 0x18000 0x8000 ; Start address for this exec region (0x18000),
; Maximum size of this exec region (0x8000)
{
program1.o (+RW, +ZI) ; Place all RW and ZI data from
; program1.o into this exec region
}
LOAD_ROM_2 0x4000 ; Start address for second load region (0x4000)
{
EXEC_ROM_2 0x4000
{
program2.o (+RO) ; Place all code and RO data from
; program2.o into this exec region
}
0x20000
0x18000
0x08000
0x00000
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DRAM
0x10000
SRAM
ROM2
ROM1