Motorola HC12 - Manual (Page 111)

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MCUez HC12 Assembler User’s Manual
MOTOROLA Sections 111
The linker PRM file contains at least:
• The name of the absolute file (command LINK)
• The name of the object file that 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). For applications
containing only absolute sections, nothing will be allocated.
• 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. For applications containing only absolute sections,
nothing will be allocated.
• The application entry point (command INIT)
• Definition of the reset vector (command VECTOR ADDRESS)
6.4.2 Relocatable Sections
The start address of a relocatable section is evaluated at link time, according to
the information stored in the linker parameter file. A relocatable section is
defined through the directive SECTION, as illustrated in
Figure 6-3 .
XDEF entry
constSec: SECTION ; Relocatable constant data section
cst1: DC.B $A6
cst2: DC.B $BC
...
dataSec: SECTION ; Relocatable data section
var: DS.B 1
codeSec: SECTION ; Relocatable code section
entry:
LDAA cst1 ; Load value in cst1
ADDA cst2 ; Add value in cst2
STAA var ; Store in var
BRA entry
Figure 6-3. Relocatable Section Programming Example