Motorola dsp assembler Reference Manual

Motorola DSP Object File Format (COFF)
Object File Components
MOTOROLA_DSP_ASSEMBLER_REFERENCE_MANUAL_E-19_Figure_E-16_Storage_Class_and_Value_Storage_Class_Value'>MOTOROLA_DSP_ASSEMBLER_REFERENCE_MANUAL_E-17_Figure_E-15_Storage_Classes_Mnemonic_Value_Type'>MOTOROLA
DSP ASSEMBLER REFERENCE MANUAL
E-17
Figure E-15 Storage Classes
Mnemonic
Value
Type
C_EFCN
-1
Physical end of function
C_NULL
0
No storage class
C_AUTO
1
Automatic variable
C_EXT
2
External symbol
C_STAT
3
Static symbol
C_REG
4
Register variable
C_EXTDEF
5
External definition
C_LABEL
6
Label
C_ULABEL
7
Undefined label
C_MOS
8
Member of structure
C_ARG
9
Function argument
C_STRTAG
10
Structure tag
C_MOU
11
Member of union
C_UNTAG
12
Union tag
C_TPDEF
13
Type definition
C_USTATIC
14
Uninitialized static
C_ENTAG
15
Enumeration tag
C_MOE
16
Member of enumeration
C_REGPARAM
17
Register parameter
C_FIELD
18
Bit field

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Motorola DSP Object File Format (COFF)
Object File Components
E-18
DSP ASSEMBLER REFERENCE MANUAL
MOTOROLA
Figure E-15 Storage Classes (continued)
The value of a symbol depends on its storage class. This relationship is summarized in
Figure E-16.
Mnemonic
Value
Type
C_BLOCK
100
Beginning and end of block
C_FCN
101
Beginning and end of function
C_EOS
102
End of structure
C_FILE
103
C language source filename
C_LINE
104
-
C_ALIAS
105
Duplicated tag
C_HIDDEN
106
-
A_FILE
200
Assembly source filename
A_SECT
201
Beginning and end of section
A_BLOCK
202
Beginning/end of COFF section
A_MACRO
203
Macro expansion
A_GLOBAL
210
Global assembly language symbol
A_XDEF
211
XDEFed symbol
A_XREF
212
XREFed symbol
A_SLOCAL
213
Section local label
A_ULOCAL
214
Underscore local label
A_MLOCAL
215
Macro local label

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Motorola DSP Object File Format (COFF)
Object File Components
MOTOROLA
DSP ASSEMBLER REFERENCE MANUAL
E-19
Figure E-16 Storage Class and Value
Storage Class
Value
C_AUTO
Stack offset in words
C_EXT
Relocatable address
C_STAT
Relocatable address
C_REG
Register number
C_LABEL
Relocatable address
C_MOS
Offset in words
C_ARG
Stack offset in words
C_STRTAG
0
C_MOU
0
C_UNTAG
0
C_TPDEF
0
C_ENTAG
0
C_MOE
Enumeration value
C_REGPARAM
Register number
C_FIELD
Bit displacement
C_BLOCK
Relocatable address
C_FCN
Relocatable address
C_EOS
Size of structure in words
C_FILE
(see below)
C_ALIAS
Tag index
C_HIDDEN
Relocatable address

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Motorola DSP Object File Format (COFF)
Object File Components
E-20
DSP ASSEMBLER REFERENCE MANUAL
MOTOROLA
Figure E-16 Storage Class and Value (continued)
If a symbol has storage class C_FILE or A_FILE, the value of that symbol equals the sym-
bol table entry index of the next C_FILE or A_FILE symbol.  That is, the C_FILE and
A_FILE entries form a one-way linked list in the symbol table.  If there are no more C_FILE
or A_FILE entries in the symbol table, the value of the symbol is the index of the first global
symbol.
Relocatable symbols have a value equal to the relocatable address of that symbol. When
the section is relocated by the Linker, the value of these symbols changes.
E.3.4.6  Auxiliary Entries
Every symbol table entry may have zero, one, or more auxiliary entries.  These auxiliary
entries are used to hold additional information about the primary symbol.  The number of
auxiliary entries associated with a given symbol can be determined by examining the
n_numaux field of the main symbol entry.
An auxiliary symbol table entry contains the same number of bytes as its associated sym-
bol table entry and is contiguous with the primary entry in the object file.  Unlike primary
symbol table entries, however, the format of an auxiliary entry depends on the type and
storage class of the main symbol.
Storage Class
Value
A_FILE
(see below)
A_SECT
String table offset to section name
A_BLOCK
Relocatable address
A_MACRO
String table offset to macro name
A_GLOBAL
Relocatable address
A_XDEF
Relocatable address
A_XREF
String table offset to symbol name
A_SLOCAL
Relocatable address
A_ULOCAL
Relocatable address
A_MLOCAL
Relocatable address

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Motorola DSP Object File Format (COFF)
Object File Components
MOTOROLA
DSP ASSEMBLER REFERENCE MANUAL
E-21
E.3.4.6.1  Filenames
The auxiliary table entry for a filename contains a 14-character array followed by an un-
signed long integer. If the integer is zero then the filename is in the array. Otherwise it is
in the string table at the offset given by the integer value. The x_ftype field indicates the
memory space used for the stack in compiled modules.
Figure E-17 Filename Symbol Auxiliary Entry
E.3.4.6.2  Sections
Section auxiliary entries have the format shown in Figure E-18. This information is analo-
gous to selected fields in the corresponding section header. If the object file is relocatable
a section symbol entry will have a second auxiliary entry with the format shown in Figure
E-19.
Figure E-18 Section Symbol Auxiliary Entry
Bytes
Declaration
Name
Description
 0-13
char
x_fname
Source file name
 14-17
unsigned long
x_foff
String table offset to file name
 18-21
unsigned long
x_ftype
Memory space used by stack
Bytes
Declaration
Name
Description
    0-3
long int
x_scnlen
Section length
    4-7
unsigned long
x_nreloc
Number of relocation entries
  8-11
unsigned long
x_nlinno
Number of line numbers
12-31
-
-
Unused (zero filled)

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