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LOC86
5-24
iAPX 86,88 Family Utilities
In-page alignment means that the entire segment must be resident within a single
256-byte page. The address of the first byte in any page has zeros in the first two
hexadecimal digits (OOH, 100H, 200H, ... OFFFOOH).
The group map has two columns: the first
i~,
the physical address (five-digit hexa-
decimal number) of the beginning of the group; the second column is the group
name, followed by the segments contained in that group. The segment names con-
tained within a given group are listed in the same column but indented slightly.
Error and Warning Messages
The error and warning messages are listed consecutively as the error situations are
encountered.
See the discussion of the interpretation of individual messages in Appendix F.
LOCS6's Algorithm for Locating Segments
Assuming that there are no errors in the invocation line or input module, LOC86
locates an input module in three stages.
1.
All absolute segments are removed from the list of segments contained in the
module.
2.
The remaining relocatable segments are ordered into a sequential list.
3.
The relocatable segments are then given absolute addresses according to each
segment's alignment, size, and memory attribute.
Absolute Segments
When LOC86 encounters an absolute segment, LOC86 removes the segment from a
list of input segments and reserves the memory area used by that segment. LOC86
maintains a map of free memory. Each time an absolute segment is encountered, the
memory space used by that segment is removed from the memory map. A segment
can become absolute in one of three ways:
1.
It may be assigned an absolute address by the translator.
2.
It may be explicitly specified in an ADDRESSES control.
3.
It may become absolute implicitly. If an absolute segment is specified in an
ORDER control, then all other segments referred to in that control, either by
segment name or by class name, are treated as absolute.
Segment Ordering
After all memory used by absolute segments has been removed from LOC86's free
memory map and before LOC86 begins assigning addresses to the remaining
relocatable segments, LOC86 prepares an ordered list of all relocatable segments.
All relocatable segments specified in an ORDER control are placed at the head of
the list.
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