Motorola dsp assembler Reference Manual

Motorola DSP Object File Format (COFF)
Object File Components
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DSP ASSEMBLER REFERENCE MANUAL
MOTOROLA_DSP_ASSEMBLER_REFERENCE_MANUAL_E-23'>MOTOROLA
Figure E-19 Relocatable Section Auxiliary Entry
The logical section number is the ordinal related to a SECTION directive in the Assembler
source file. The relocation section number usually is the same as the logical section num-
ber, but may be different if the logical section is static within an enclosing section. The
memory mapping is an alternate encoding of the CORE_ADDR information in the section
header. Section type flags indicate whether this COFF section represents a buffer or over-
lay block. If the current COFF section is a buffer or overlay block a third auxiliary entry is
produced. The layout of that entry is shown in Figure E-19.
Figure E-20 Relocatable Buffer/Overlay Auxiliary Entry
Buffers and overlays are generally mutually exclusive so their respective fields share stor-
age space in the record definition. In the case where a buffer appears in an overlay, an-
Bytes
Declaration
Name
Description
    0-3
long int
secno
Logical section number
    4-7
long int
rsecno
Logical relocation section number
  8-11
long int
flags
Section type flags
12-27
struct mematt
mem
Section memory attributes
28-31
-
-
Unused (zero filled)
Bytes
Declaration
Name
Description
    0-3
long int
bufcnt
Buffer section number
    4-7
long int
buftyp
Buffer type
  8-11
long int
buflim
Buffer limit
  0-15
struct mematt
ovlmem
Overlay memory attributes
16-19
long int
ovlcnt
Overlay section number
20-23
long int
ovlstr
Overlay origin expression
24-31
-
-
Unused (zero filled)

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Motorola DSP Object File Format (COFF)
Object File Components
MOTOROLA
DSP ASSEMBLER REFERENCE MANUAL
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other auxiliary entry is generated for the buffer. The buffer section number is really the
buffer instance count in this file.   Buffer type is either modulo or reverse carry. The buffer
limit gives the upper bound for the buffer size even though the block may contain less ini-
tialized data than this limit suggests. The overlay memory structure gives the runtime
memory attributes for this block. The overlay section number is really the overlay instance
count in this file. The overlay origin expression is the expression given for the runtime
counter in the Assembler ORG directive (see Chapter 6).
E.3.4.6.3  Tag Names
Auxiliary entries for C language structure and union tag names have the format described
in Figure E-21. Note that in Motorola DSP COFF the size of the associated structure or
union is in words as opposed to bytes as in standard COFF. The x_endndx field is used
to create a linked list of tag name entries through the symbol table.
Figure E-21 Tag Name Symbol Auxiliary Entry
E.3.4.6.4  End of Structures
The format for C language end-of-structure auxiliary entries is given in Figure E-22. Note
that the size of the structure, union, or enumeration is given in words rather than bytes.
The tag index holds the symbol table index for the tag record associated with this struc-
ture.
Bytes
Declaration
Name
Description
    0-7
-
-
Unused (zero filled)
  8-11
unsigned long
x_size
Size of structure, union, or
enumeration in words
12-15
-
-
Unused (zero filled)
16-19
long int
x_endndx
Index of next structure, union, or
enumeration entry
20-31
-
-
Unused (zero filled)

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Motorola DSP Object File Format (COFF)
Object File Components
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DSP ASSEMBLER REFERENCE MANUAL
MOTOROLA
Figure E-22 End of Structure Auxiliary Entry
E.3.4.6.5  Functions
Function auxiliary entries have the format shown in Figure E-23. Note that the size of the
function is given in words rather than bytes. The function tag index holds the symbol table
index to the begin-function symbol for this function. The x_endndx field points to the next
function symbol table entry. The x_lnnoptr field contains a byte offset pointer within the
object file to the line number entry that signals the start of this function (see section
E.3.3.3,   Line Numbers, for more information).
Figure E-23 Function Symbol Auxiliary Entry
Bytes
Declaration
Name
Description
    0-3
long int
x_tagndx
Tag index
    4-7
-
-
Unused (zero filled)
  8-11
unsigned long
x_size
Size of structure, union, or
enumeration in words
12-31
-
-
Unused (zero filled)
Bytes
Declaration
Name
Description
    0-3
long int
x_tagndx
Tag index
    4-7
long int
x_fsize
Size of function in words
  8-11
-
-
Unused (zero filled)
12-15
long int
x_lnnoptr
File pointer to line number entry
16-19
long int
x_endndx
Index of next function entry
20-31
-
-
Unused (zero filled)

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Motorola DSP Object File Format (COFF)
Object File Components
MOTOROLA
DSP ASSEMBLER REFERENCE MANUAL
E-25
E.3.4.6.6  Arrays
The format for C language array auxiliary entries is given in Figure E-24. The tag index
contains the offset to the next array symbol in the symbol table. The line number field
gives the source file line number for the array declaration.
Figure E-24 Array Symbol Auxiliary Entry
E.3.4.6.7  End of Blocks and Functions
The format for C language symbol entries for the end of blocks and functions is given in
Figure E-25. Only the source file line number for the end of the block or function is stored.
Figure E-25 End of Block or Function Auxiliary Entry
Bytes
Declaration
Name
Description
    0-3
long int
x_tagndx
Tag index
    4-7
unsigned long
x_lnno
Line number of array declaration
  8-11
unsigned long
x_size
Size of array
12-15
unsigned long
x_dimen[0]
First array dimension
16-19
unsigned long
x_dimen[1]
Second array dimension
20-23
unsigned long
x_dimen[2]
Third array dimension
24-27
unsigned long
x_dimen[3]
Fourth array dimension
28-31
-
-
Unused (zero filled)
Bytes
Declaration
Name
Description
    0-3
-
-
Unused (zero filled)
    4-7
unsigned long
x_lnno
Source file line number
  8-31
-
-
Unused (zero filled)

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