Introduction
rce modules and binary objects for host systems are compiled and linked with the gnu compiler and binutils collections. The build tool is gmake.
This chapter covers:
- General compilation and linking requirements
- Makefile and build product hierarchy
- Global make variables
- Constituent makefiles
- Packages and project makefiles
- Make examples
- Make invocation options
- Compiler options for rce modules
- gnu linker options for rce modules
The reader is assumed to be familiar with the tools in the gnu collection.
General compilation and linking requirements
While naturally the build system automates much of the compilation and linking process, developers must manage build dependencies manually, setting up makefiles such that modules and objects "lower" on the dependency graph are built before those "higher" on the graph.
rce modules
The rce uses elf (Embedded and Linking Format) as the native object code format for its module objects.
Modules can be built up at compile/link time from traditional static (".a") libraries and/or shared object (".so") libraries prepared using the rce repository make system. Modules can also contain static code (".a") from host system or third-party libraries, but such libraries must be (re)compiled with options required by the dynamic linker. See Section 7.9.
The dynamic linker fails if presented with duplicate symbol names. A given symbol can be used in more than one module, but only if those modules are never loaded together.
Host objects
TBW.
Makefile and build product hierarchy
Source code in the rce repository is organized using a two-level structure in which projects contain one or more packages. Packages contain code and makefiles for the construction of one or more constituents.
As discussed in Chapter Y, the pkgcreate.py script automates the creation of project and package directories and generic "blank" makefiles.
A set of repository-level makefiles allows gmake to be invoked at the top level to build all packages and projects locally, or build a full release of rce software. A set of makefile templates is used to clone new projects and packages. See Figure 4.
Hierarchy of repository-level makefiles
Building all projects at once is the exception. Typically, development iterations involve building and re-building individual packages and constituents. Figure 5 depicts the makefiles relevant to package and constituent builds.
Hierarchy of package- and constituent-level makefiles
Makefile search path
[How "export library symbols...just like symbols in module sources."]
Inter-package and inter-project dependencies
Must be handled manually
If A depends on B, build B first
Order of projects in projects.mk
Order of packages in packages.mk
Library search order
When linking each library is searched once
In lists of libraries put the lower-level libs first
The search order will be the reverse of that listed
Build product hierarchy
TBW.
Directory structure for rce build products
Global make variables
-Under construction-
The repository-level makefiles define a set of global make variables that can be useful to cite in package- and constituent-level makefiles, and which set compiler options for various targets.
These reflect the platform information make variables derived from $(tgt_arch)
make variable compiler option
tgt_os == "linux" -Dtgt_os_linux
tgt_cpu_family == "ppc" -Dtgt_cpu_family_ppc
tgt_opt == "" -Dtgt_opt_
tgt_opt == "dbg" -Dtgt_opt_dbg
tgt_board == "" -Dtgt_board_
tgt_board == "rce405" -Dtgt_board_rce405
Other variables record the location of intermediate and final build products. See Figure 6.
Build directories for rce module code:
modobjdir
modlibdir
moddir
Build directories for host (non-module) code:
objdir
libdir
bindir
Constituent makefiles
This section describes the most common make rules and option flags for building constituents.
Constituent make rules for rce modules
The minimal constituent.mk file for building an rce module is shown below.
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h2. Introduction rce modules and binary objects for host systems are compiled and linked with the gnu compiler and binutils collections. The build tool is gmake. This chapter covers: * General compilation and linking requirements * Makefile and build product hierarchy * Global make variables * Constituent makefiles * Packages and project makefiles * Make examples * Make invocation options * Compiler options for rce modules * gnu linker options for rce modules The reader is assumed to be familiar with the tools in the gnu collection. h2. General compilation and linking requirements While naturally the build system automates much of the compilation and linking process, developers must manage build dependencies manually, setting up makefiles such that modules and objects "lower" on the dependency graph are built before those "higher" on the graph. h3. rce modules The rce uses elf (Embedded and Linking Format) as the native object code format for its module objects. Modules can be built up at compile/link time from traditional static (".a") libraries and/or shared object (".so") libraries prepared using the rce repository make system. Modules can also contain static code (".a") from host system or third-party libraries, but such libraries must be (re)compiled with options required by the dynamic linker. See Section 7.9. The dynamic linker fails if presented with duplicate symbol names. A given symbol can be used in more than one module, but only if those modules are never loaded together. h3. Host objects TBW. h2. Makefile and build product hierarchy Source code in the rce repository is organized using a two-level structure in which projects contain one or more packages. Packages contain code and makefiles for the construction of one or more constituents. As discussed in Chapter Y, the pkgcreate.py script automates the creation of project and package directories and generic "blank" makefiles. A set of repository-level makefiles allows gmake to be invoked at the top level to build all packages and projects locally, or build a full release of rce software. A set of makefile templates is used to clone new projects and packages. See Figure 4. Hierarchy of repository-level makefiles Building all projects at once is the exception. Typically, development iterations involve building and re-building individual packages and constituents. Figure 5 depicts the makefiles relevant to package and constituent builds. Hierarchy of package- and constituent-level makefiles h3. Makefile search path [[Note: How "export library symbols...just like symbols in module sources."]] Inter-package and inter-project dependencies Must be handled manually If A depends on B, build B first Order of projects in projects.mk Order of packages in packages.mk Library search order When linking each library is searched once In lists of libraries put the lower-level libs first The search order will be the reverse of that listed h3. Build product hierarchy TBW. Directory structure for rce build products h2. Global make variables --Under construction-- The repository-level makefiles define a set of global make variables that can be useful to cite in package- and constituent-level makefiles, and which set compiler options for various targets. These reflect the platform information make variables derived from $(tgt_arch) make variable compiler option tgt_os == "linux" -Dtgt_os_linux tgt_cpu_family == "ppc" -Dtgt_cpu_family_ppc tgt_opt == "" -Dtgt_opt_ tgt_opt == "dbg" -Dtgt_opt_dbg tgt_board == "" -Dtgt_board_ tgt_board == "rce405" -Dtgt_board_rce405 Other variables record the location of intermediate and final build products. See Figure 6. Build directories for rce module code: modobjdir modlibdir moddir Build directories for host (non-module) code: objdir libdir bindir h2. Constituent makefiles This section describes the most common make rules and option flags for building constituents. h3. Constituent make rules for rce modules The minimal constituent.mk file for building an rce module is shown below. {code}ifeq ($(tgt_os),rtems) modnames := hellomod majorv_hellomod := 1 minorv_hellomod := 2 branch_hellomod := prod modsrcs_hellomod := hellomod.cc endif {code} |
The
...
following
...
rules
...
are
...
required.
...
Rule | Description | Example |
|---|---|---|
modnames | Human-friendly |
...
module |
...
name. |
...
|
...
parts |
...
of |
...
the |
...
module |
...
|
...
recorded |
...
in |
...
XXX |
...
section. |
...
modnames |
...
:= |
...
transport |
...
modsrcs_<modname> |
...
List |
...
source |
...
files |
...
from |
...
which |
...
the |
...
module |
...
is |
...
to |
...
be |
...
built, |
...
separated |
...
by |
...
space(s). |
...
modsrcs_transport |
...
:= |
...
main.cc |
...
open.cc |
...
majorv_<modname> |
...
Module |
...
major |
...
version |
...
number. |
...
|
...
parts |
...
of |
...
the |
...
module |
...
|
...
majorv_transport |
...
:= |
...
1 |
...
minorv_<modname> |
...
Module |
...
minor |
...
version |
...
number. |
...
|
...
parts |
...
of |
...
the |
...
module |
...
|
...
minorv_transport |
...
:= |
...
2 |
...
branch_<modname> |
...
Module |
...
branch |
...
identifier. |
...
|
...
parts |
...
of |
...
the |
...
module |
...
|
...
branch_transport |
...
:= |
...
test |
...
The
...
following
...
optional
...
rules
...
define
...
dependencies
...
and
...
identify
...
include
...
directories
...
to
...
be
...
searched.
...
Rule | Description | Example |
|---|---|---|
modsneeded_<modname> |
...
Used |
...
to |
...
record |
...
any |
...
indirect |
...
dependencies |
...
the |
...
client |
...
module |
...
may |
...
have |
...
on |
...
other |
...
modules |
...
at |
...
run |
...
time, |
...
which |
...
the |
...
dynamic |
...
linker |
...
cannot |
...
infer. |
...
|
...
the |
...
project |
...
and |
...
soname |
...
of |
...
the |
...
required |
...
module(s). |
...
Wildcards |
...
are |
...
not |
...
allowed; |
...
the |
...
dynamic |
...
linker |
...
will |
...
insist |
...
on |
...
the |
...
specified |
...
module. |
...
Compatibility |
...
requirements |
...
can |
...
be |
...
relaxed |
...
by |
...
including |
...
an |
...
rce_isCompatible |
...
function |
...
in |
...
the |
...
client |
...
module, |
...
per |
...
Chapter |
...
X. |
...
modsneeded_transport |
...
:= |
...
\ |
...
\ |
...
|
...
core |
...
under |
...
rce |
...
project? |
...
modincs_<modname> |
...
Header |
...
file |
...
include |
...
directories |
...
for |
...
headers |
...
inside |
...
the |
...
RCE |
...
release |
...
tree. |
...
modincs_transport |
...
:= |
...
\ |
...
|
...
modsinc_<modname> |
...
Header |
...
file |
...
include |
...
directories |
...
for |
...
headers |
...
outside |
...
the |
...
RCE |
...
release |
...
tree. |
...
|
...
system |
...
pathname |
...
required. |
...
modsinc_transport |
...
:\ |
...
The
...
following
...
optional
...
rules
...
govern
...
how
...
static
...
and
...
shared
...
object
...
libraries
...
appropriate
...
for
...
linking
...
into
...
an
...
rce
...
module
...
at
...
build
...
time
...
are
...
themselves
...
built
...
and/or
...
located
...
for
...
linking
...
to
...
the
...
target
...
module
...
by
...
gnu
...
ld.
...
Module
...
makefiles:
...
optional
...
static
...
and
...
shared
...
object
...
library
...
make
...
rules
...
Rule
...
Description
...
Example
...
modlibs_<modname>
...
Names
...
of
...
"internal"
...
static
...
or
...
shared
...
object
...
libraries
...
in
...
the
...
repository
...
/build/../modlib
...
sub-tree;
...
these
...
libraries
...
are
...
to
...
be
...
linked
...
into
...
the
...
target
...
module
...
at
...
build
...
time
...
(as
...
opposed
...
to
...
dynamically
...
linked
...
at
...
run
...
time).
...
See
...
Figure
...
6.
...
Identify
...
the
...
project,
...
followed
...
by
...
the
...
library
...
object,
...
omitting
...
"lib"
...
prefix
...
and
...
".a"
...
or
...
".so"
...
suffixes.
...
modlibs_transport
...
:=
...
rce/enet
...
modslib_<modname>
...
Names
...
of
...
"external"
...
system
...
or
...
third-party
...
static
...
libraries
...
to
...
be
...
linked
...
into
...
the
...
target
...
module
...
at
...
build
...
time
...
(as
...
opposed
...
to
...
dynamically
...
linked
...
at
...
run
...
time).
...
Specify
...
the
...
full
...
system
...
path
...
and
...
end
...
with
...
the
...
library
...
object
...
name,
...
omitting
...
"lib"
...
prefix
...
and
...
".a"
...
suffix.
...
modslib_packet
...
:=
...
\
/opt/lib/hdr
...
modlibnames
...
Name
...
of
...
an
...
"internal"
...
library
...
to
...
build;
...
the
...
resulting
...
library
...
is
...
suitable
...
for
...
linking
...
into
...
a
...
module
...
at
...
build
...
time.
...
Name
...
the
...
library,
...
omitting
...
"lib"
...
prefix
...
and
...
any
...
suffix.
...
modlibnames
...
:=
...
foo
...
libsrcs_<modlibname>
...
Source
...
files
...
to
...
use
...
in
...
building
...
an
...
"internal"
...
library.
...
libsrcs_foo
...
:=
...
alpha.cc
...
beta.cc
...
libincs_<modlibname>
...
Header
...
file
...
include
...
directories
...
for
...
headers
...
inside
...
the
...
rce
...
release
...
tree.
...
libincs_foo
...
:=
...
rce/fci
...
libsinc_<modlibname>
...
Header
...
file
...
include
...
directories
...
for
...
headers
...
outside
...
the
...
rce
...
release
...
tree.
...
Full
...
system
...
pathname
...
required.
...
libsinc_foo
...
:=
...
/usr/lib/net
...
The
...
following
...
example
...
constituents.mk
...
file
...
illustrates
...
the
...
use
...
of
...
these
...
optional
...
make
...
rules
...
in
...
building
...
an
...
rce
...
module,
...
george.1.0.example,
...
which
...
is
...
composed
...
of
...
its
...
own
...
compiled
...
sources
...
as
...
well
...
as
...
two
...
internal
...
libraries
...
in
...
the
...
fci
...
and
...
enet
...
projects
...
(libcontainer
...
and
...
libutil)
...
and
...
an
...
external
...
library
...
(libmodcommon).
...
Make
...
instructions
...
for
...
the
...
libcontainer
...
library
...
are
...
included
...
in
...
the
...
george
...
makefile,
...
and
...
the
...
two
...
are
...
built
...
as
...
part
...
of
...
the
...
same
...
sequence.
| Code Block |
|---|
} ifeq ($(tgt_os),rtems) modnames := george modsrcs_george := src/abel.cc src/baker.cc majorv_george := 1 minorv_george := 0 branch_george := example modsneeded_george := \ proj1/fred.1.2.prod \ proj2/mary.2.0.devel modincs_george := proj1/pkg1 proj2/pkg2 modsinc_george := /group/util /usr/include/bits modlibs_george := fci/container enet/util modslib_george := /opt/lib/modcommon modlibnames := container libsrcs_foo := alpha.cc beta.cc gamma.cc libincs_foo := proj1/pkg1 libsinc_foo := /usr/include endif {code} h3. Constituent make rules for host objects TBW. h2. |
Constituent make rules for host objects
TBW.
Packages and project makefiles
This section describes the most common make rules and option flags for packages.mk and project.mk. See Chapter Z for definitions of all options.
Use application-specific files
projects.mk at top level
packages.mk for projects
Make examples
gmake is invoked as follows:
| Code Block |
|---|
Packages and project makefiles This section describes the most common make rules and option flags for packages.mk and project.mk. See Chapter Z for definitions of all options. Use application-specific files projects.mk at top level packages.mk for projects h2. Make examples gmake is invoked as follows: {code} gmake [<pathspec>.]<targetspec>[.<action>] {code} |
Where:
...
- <pathspec>
...
- is
...
- an
...
- optional
...
- argument
...
- available
...
- at
...
- the
...
- top
...
- (release)
...
- level,
...
- allowing
...
- the
...
- build
...
- to
...
- be
...
- limited
...
- to
...
- a
...
- particular
...
- project
...
- or
...
- package.
...
- See
...
- Section
...
- 7.8.1.
...
- <targetspec>
...
- is
...
- a
...
- required
...
- argument
...
- defining
...
- the
...
- platform
...
- and
...
- optimization
...
- level
...
- for
...
- the
...
- build.
...
- See
...
- Section
...
- 7.8.2.
...
- <action>
...
- is
...
- an
...
- optional
...
- gmake
...
- build
...
- action.
...
- See
...
- Section
...
- 7.8.3.
...
Build
...
all
...
projects
...
and
...
packages
...
When
...
executed
...
from
...
the
...
top
...
of
...
the
...
release
...
tree,
...
gmake
...
builds
...
all
...
release
...
products
...
for
...
a
...
specified
...
target.
...
In
...
the
...
following
...
example,
...
gmake
...
is
...
used
...
to
...
build
...
the
...
complete
...
set
...
of
...
linux
...
products
...
(objects,
...
libraries,
...
modules,
...
executables)
...
for
...
the
...
PPC
...
and
...
386
...
platforms.
| Code Block |
|---|
} // change directory to top of release tree prompt> gmake ppc-linux prompt> gmake i386-linux {code} h3. Build individual projects or packages TBW. |
Build individual projects or packages
TBW.
| Code Block |
|---|
{code} // change directory to top of release tree prompt> gmake rce.shell.ppc-rtems-rce405 // change directory to rce prompt> gmake shell.ppc-rtems-rce405 {code} |
Compile
...
sources
...
for
...
a
...
single
...
project
...
and
...
use
...
a
...
make
...
rule
...
to
...
build
...
libraries
...
only
...
TBW.
| Code Block |
|---|
{code} // change directory to top of release tree prompt> gmake rceapp.console.ppc-rtems-rce405.obj {code} h2. Make |
Make invocation options
Path specification
gmake can be invoked at the release, project, or package level.
At the release level, use the path specification to limit the build to a particular project or package.
| Code Block |
|---|
invocation options h3. Path specification gmake can be invoked at the release, project, or package level. At the release level, use the path specification to limit the build to a particular project or package. {code} prompt> gmake rce.ppc-rtems-rce405 {code} { |
| Code Block |
|---|
code} prompt> gmake rceapp.console.ppc-rtems-rce405 {code} |
The
...
latter
...
is
...
equivalent
...
to:
| Code Block |
|---|
} prompt> cd rceapp/console prompt> gmake ppc-rtems-rce405 {code} h3. Target specification The target specification consists of up to four elements, separated by a dash. Valid specifications are defined in |
Target specification
The target specification consists of up to four elements, separated by a dash. Valid specifications are defined in release/make/sw/flags.mk.
...
Element | Description |
|---|---|
family | Target processor family. |
...
'sparc', |
...
'ppc' |
...
OS | Target operating system. |
...
'solaris', |
...
'rtems' |
...
board | Can be one of: 'rce405', |
...
'ml405'. |
...
|
...
This |
...
element |
...
is |
...
only |
...
valid |
...
for |
...
OS |
...
'rtems' |
...
optimization | Compiler optimization level. |
...
"dbg" |
...
The
...
set
...
of
...
valid
...
target
...
specifications
...
is
...
as
...
follows.
| Code Block |
|---|
} ppc-linux ppc-rtems-rce405 ppc-rtems-ml405 i386-linux x86_64-linux sparc-solaris {code} h3. Make actions *If a rule is not specified, then what is built?* ||Make rule ||Description|| |all |Build 'bin' and user-defined | |dir |Create build directories, but do not build.| |obj |Compile sources | |lib |Build libraries from object files | |bin |Build libraries, executables and modules | |clean |Remove all built products | |cleanall| Same as 'clean', but removes some tmp directories as well| |print |List what is built and where it goes | h2. Compiler options for rce modules The following compiler options are invoked via |
Make actions
If a rule is not specified, then what is built?
Make rule | Description |
|---|---|
all | Build 'bin' and user-defined |
dir | Create build directories, but do not build. |
obj | Compile sources |
lib | Build libraries from object files |
bin | Build libraries, executables and modules |
clean | Remove all built products |
cleanall | Same as 'clean', but removes some tmp directories as well |
List what is built and where it goes |
Compiler options for rce modules
The following compiler options are invoked via /make/sw/flags.mk.
...
They
...
are
...
presented
...
here
...
for
...
reference.
...
-shared |
...
The
...
linker
...
will
...
expect
...
each
...
module
...
to
...
have
...
a
...
"dynamic
...
section"
...
and
...
a
...
hash
...
table
...
for
...
those
...
symbols
...
with
...
global
...
visibility.
...
|
-fno-pic |
...
Although
...
pic
...
saves
...
on
...
relocations
...
(one
...
per
...
function
...
instead
...
of
...
one
...
per
...
function
...
call)
...
it
...
requires
...
the
...
dynamic
...
linker
...
to
...
know
...
the
...
special
...
relocation
...
types
...
needed
...
for
...
the
...
Global
...
Offset
...
Table
...
and
...
the
...
Procedure
...
Linkage
...
Table.
...
The
...
latter
...
is
...
especially
...
tricky
...
to
...
get
...
right.
...
It's
...
simpler
...
to
...
use
...
non-pic
...
and
...
just
...
deal
...
with
...
the
...
regular
...
relocations.
...
The
...
other
...
usual
...
reason
...
to
...
use
...
pic
...
(that
...
most
...
of
...
the
...
code
...
can
...
be
...
mapped
...
into
...
multiple
...
address
...
spaces
...
at
...
the
...
same
...
time)
...
doesn't
...
apply
...
here
...
since
...
rtems
...
only
...
offers
...
one
...
global
...
address
...
space.
...
|
-nostdlib |
...
We
...
supply
...
our
...
own
...
module
...
_init
...
(rce_modinit)
...
and
...
module
...
_fini
...
(rce_modfinish)
...
code.
...
Another
...
reason
...
not
...
to
...
use
...
the
...
standard
...
_init/_fini
...
code
...
is
...
that
...
their
...
source
...
code
...
was
...
compiled
...
with
...
-fpic.
...
-nostdlib
...
also
...
prevents
...
searching
...
of
...
the
...
standard
...
C++
...
libraries.
...
Instead
...
we'll
...
want
...
to
...
search
...
the
...
symbol
...
table
...
of
...
the
...
RTEMS+newlib
...
executable
...
either
...
at
...
the
...
time
...
the
...
module
...
is
...
produced
...
or
...
at
...
run
...
time.
...
-fvisiblity=hidden |
...
A
...
shared
...
object
...
actually
...
has
...
two
...
symbol
...
tables,
...
the
...
normal
...
one
...
and
...
a
...
special
...
"dynamic"
...
table.
...
The
...
latter
...
is
...
the
...
one
...
that
...
is
...
searched
...
in
...
order
...
to
...
resolve
...
inter-object
...
references.
...
In
...
the
...
past
...
pretty
...
much
...
every
...
non-static
...
symbol
...
from
...
every
...
object
...
code
...
file
...
used
...
to
...
make
...
the
...
shared
...
object
...
went
...
into
...
the
...
dynamic
...
table.
...
Since
...
GCC
...
4.0
...
the
...
compiler
...
recognizes
...
the
...
-visibility
...
option
...
which
...
controls
...
the
...
default
...
visibility
...
of
...
symbols.
...
Using
...
-fvisibility=hidden
...
makes
...
"hidden"
...
the
...
default.
...
Hidden
...
symbols
...
don't
...
go
...
into
...
the
...
dynamic
...
symbol
...
table
...
so
...
one
...
can
...
dramatically
...
reduce
...
its
...
size.
...
To
...
make
...
sure
...
that
...
the
...
symbols
...
associated
...
with
...
a
...
variable,
...
function
...
or
...
class
...
do
...
make
...
it
...
into
...
the
...
dynamic
...
symbol
...
table
...
you
...
need
...
to
...
mark
...
it
...
with
...
_attribute_
...
((visibility
...
("default"))):
| Code Block |
|---|
#define EXPORT __attribute__((visibility ("default"))) int EXPORT counter; int EXPORT foo(int i) { ... }; class EXPORT bar { ... }; |
-fvisibility=hidden
...
also
...
hides
...
out-of-line
...
code
...
generated
...
for
...
inline
...
functions
...
and
...
other
...
compiler-generated
...
code.
...
|
-mlongcall |
...
By
...
default
...
GCC
...
will
...
compile
...
function
...
calls
...
into
...
branch
...
instructions
...
which
...
use
...
26-bit
...
PC-relative
...
offsets.
...
In
...
general
...
this
...
won't
...
be
...
adequate
...
for
...
inter-module
...
calls
...
so
...
the
...
compiler
...
must
...
be
...
instructed
...
to
...
make
...
all
...
function
...
calls
...
"long"
...
calls.
...
These
...
use
...
full
...
32-bit
...
addresses
...
at
...
the
...
cost
...
of
...
some
...
speed.
...
|
Compiler
...
options
...
required
...
for
...
rebuilding
...
system
...
or
...
third-party
...
libraries
...
TBW.
| Code Block |
|---|
ifeq ($(tgt_cpu_family)-$(tgt_os),ppc-rtems) AS := powerpc-rtems-as CPP := powerpc-rtems-cpp CC := powerpc-rtems-gcc CXX := powerpc-rtems-g++ LD := powerpc-rtems-ld LX := powerpc-rtems-g++ ifeq ($(tgt_board),rce405) RTEMSDIR := $(RELEASE_DIR)/build/rtems/target/powerpc-rtems/rce405/lib endif ifeq ($(tgt_board),ml405) RTEMSDIR := $(RELEASE_DIR)/build/rtems/target/powerpc-rtems/ml405/lib endif LDTOOLSD := $(RELEASE_DIR)/rce/ldtools LIBEXTNS := a DEPFLAGS := -B$(RTEMSDIR) -MM DEFINES += -Dppc405 CPPFLAGS := CFLAGS := -B$(RTEMSDIR) -specs bsp_specs -qrtems -mcpu=403 -Wall CXXFLAGS := $(CFLAGS) CASFLAGS := -x assembler-with-cpp -P $(CFLAGS) LDFLAGS := -r LXFLAGS := -B$(RTEMSDIR) -specs $(LDTOOLSD)/dynamic_specs \ -qrtems -qnolinkcmds -Wl,-T$(LDTOOLSD)/dynamic.ld \ -mcpu=403 MANAGERS := timer sem msg event signal part region dpmem io rtmon ext mp MDEFINES := $(DEFINES) -DEXPORT='__attribute__((visibility("default")))' MCFLAGS := -B$(RTEMSDIR) -specs $(LDTOOLSD)/module_specs \ -qrtems -Wall -fvisibility=hidden -mlongcall -fno-pic -mcpu=403 MCXXFLAGS := $(MCFLAGS) MCASFLAGS := -x assembler-with-cpp -P $(MCFLAGS) MLDFLAGS := -r MLXFLAGS := -B$(RTEMSDIR) -specs $(LDTOOLSD)/module_specs \ -qrtems -qnolinkcmds -Wl,-T$(LDTOOLSD)/module.ld-mcpu=403 \ -shared -nostdlib |
gnu
...
linker
...
options
...
for
...
rce
...
modules
...
The
...
following
...
gnu
...
ld
...
options
...
are
...
invoked
...
via
...
/make/sw/flags.mk.
...
They
...
are
...
presented
...
here
...
for
...
reference.
...
Static
...
linking
...
must
...
be
...
done
...
by
...
calling
...
ld
...
explicitly,
...
rather
...
than
...
relying
...
on
...
g++
...
to
...
do
...
it
...
implicitly.
...
The
...
latter
...
uses
...
the
...
linker
...
option
...
--eh-frame-hdr
...
which
...
causes
...
ld
...
to
...
abort
...
with
...
an
...
error
...
about
...
a
...
"non-representable
...
section"
...
in
...
the
...
output.
...
-shared |
...
and |
...
-nostdlib |
...
as
...
for
...
g++.
...
|
-z |
...
combreloc |
...
Makes
...
sure
...
that
...
all
...
relocation
...
table
...
entries
...
go
...
into
...
a
...
single
...
contiguous
...
sub-region
...
of
...
the
...
shared
...
object,
...
even
...
if
...
by
...
mischance
...
they
...
end
...
up
...
in
...
more
...
than
...
one
...
output
...
section.
...
This
...
option
...
also
...
causes
...
the
...
linker
...
to
...
sort
...
the
...
entries
...
so
...
that
...
those
...
reference
...
the
...
same
...
symbol
...
occur
...
together.
...
This
...
allows
...
the
...
dynamic
...
linker
...
to
...
use
...
a
...
one-entry
...
symbol
...
lookup
...
cache.
...
|
-T |
...
scriptname |
...
Use
...
the
...
custom
...
linker
...
script.
...
|
-Map |
...
filename |
...
to
...
make
...
a
...
link
...
map.
...
|
-soname |
...
modulename.major.minor.branch |
...
to
...
set
...
the
...
soname
...
field
...
to
...
the
...
module's
...
name
...
with
...
version
...
numbers
...
and
...
development
...
branch
...
appended.
...
|
-o |
...
modulename.major.minor.branch.so |
...
Module
...
filename.
...
|
-fhash-style=sysv |
...
to
...
suppress
...
generation
...
of
...
a
...
GNU-style
...
hash
...
table.
...
|
Each
...
module
...
that
...
the
...
one
...
being
...
constructed
...
depends
...
on
...
should
...
be
...
named
...
on
...
the
...
linker
...
command
...
line
...
so
...
that
...
each
...
of
...
their
...
sonames
...
will
...
be
...
recorded
...
in
...
a
...
DT_NEEDED
...
entry
...
in
...
the
...
elf
...
dynamic
...
section.
...
This
...
defines
...
a
...
minimum
...
set
...
of
...
compatbility
...
requirements;
...
compatibility
...
requirements
...
can
...
be
...
expanded
...
by
...
implementing
...
an
...
rce_isCompatible
...
function,
...
as
...
described
...
in
...
Chapter
...
Y.
...
Can
...
set
...
rce
...
core
...
comaptibility
...
here?
...
Is
...
this
...
optional,
...
only
...
for
...
cases
...
where
...
the
...
dependency
...
is
...
not
...
direct?
...
Won't
...
dynalink
...
try
...
to
...
resolve?
...