1204
MS-DOS User's
Reference
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The
frame
number
of
a
segment
can
be
obtained
from a
link
file.
The
frame
number
is
the
first five hexadecimal digits
of
the
start
address specified for
the
segment.
Order
of
Segments
Link copies segments
to
the
executable file
in
the
same
order
that it encounters
them
in
the
object
files.
The
linker maintains
this
order
throughout
the
program unless it
encounters
two
or
more
segments
with
the
same class name. Segments
with
identical
class names belong
to
the
same class type,
and
are
copied
to
the
executable file as contiguous blocks.
The
Microsoft Macro Assembler Reference
Manual
includes a
more
detailed discussion
of
segment loading
order
and
methods
of
controlling loading
order
by
assigning class types.
Combined
Segments
Link uses
combine
types
to
determine
whether
two
or
more
seg-
ments
sharing
the
same
name
should
be
combined
into
a single
large segment.
The
combine
types are public, stack,
common,
memory, at, and private. Combine types are also described
in
the
Microsoft Macro Assembler Reference Manual.
[
[
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E
Public combine types
If
a segment has a public
combine
type,
the
linker automatically
Stack combine types
combines
it
with
any
other
segments
that
have
the
same
name [
and
belong
to
the
same class.
When
link
combines
segments, it
ensures that
the
segments are contiguous and
that
all addresses in
the
segments can
be
accessed using an offset from
the
same frame
address.
The
result is
the
same as
if
the
segment
were
defined as [
a
whole
in
the
source
file.
The
linker preserves each segment's align type. This means
that
even
though
the
segments
belong
to
a single, large segment,
the
[
code
and data in
the
segments retain
their
original align type.
If
the
combined
segments
exceed
64K bytes,
link
displays an
error
message.
If
a
segment
has a stack
combine
type,
the
linker carries
out
the
same
combine
operation as for public segments.
The
only differ-
ence
is
that
stack segments cause
link
to
copy
an initial stack-
pointer
value
to
the
executable file. This stack-pOinter value is
the
offset
to
the
end
of
the
first stack segment
(or
combined
stack
segment)
that
the
linker encounters.
If
you
use
the
stack type for stack segments,
you
do
not
need
to
give instructions
to
load
the
segment into
the
SS
register.
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