Motorola HC12 - Manual (Page 113)

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MCUez HC12 Assembler User’s Manual
MOTOROLA Sections 113
The linker PRM file contains at least:
• The name of the absolute file (command LINK)
• The name of the object file which should be linked (command NAMES)
• Specification of a memory area where the sections containing variables
must be allocated. At least the predefined section
.data must be placed
there (command SEGMENTS and PLACEMENT).
• Specification of a memory area where the sections containing code or
constants must be allocated. At least the predefined section .
text must
be placed there (command SEGMENTS and PLACEMENT).
• Specification of application entry point (command INIT)
• Definition of the reset vector (command VECTOR ADDRESS)
According to the PRM file in Figure 6-4 :
• The section dataSec will be allocated starting at 0x0800 .
• The section constSec will be allocated starting at 0x0B00.
• The section codeSec will be allocated next to the section constSec .
When the constant, code, and data sections cannot be allocated consecutively,
the PRM file used to link the previous example can be defined like this:
LINK test.abs /* Name of the executable file generated. */
NAMES
test.o
/* Name of the object files in the application. */
END
SEGMENTS
ROM_AREA_1= READ_ONLY 0xB00 TO 0xB7F; /* READ_ONLY memory area. */
ROM_AREA_2= READ_ONLY 0xC00 TO 0xC7F;/* READ_ONLY memory area. */
RAM_AREA_1= READ_WRITE 0x800 TO 0x87F;/* READ_WRITE memory area. */
RAM_AREA_2= READ_WRITE 0x900 TO 0x97F;/* READ_WRITE memory area. */
END
PLACEMENT
/* Relocatable variable sections are allocated in MY_RAM. */
dataSec INTO RAM_AREA_2;
.data INTO RAM_AREA_1;
/* Relocatable code and constant sections are allocated in MY_ROM. */
constSec INTO ROM_AREA_2;
codeSec, .text INTO ROM_AREA_1;
END
INIT entry
/* Application entry point. */
VECTOR ADDRESS 0xFFFE entry /* Initialization of the reset vector. */
Figure 6-5. Defining Multiple RAM and ROM Areas