Compiling and Linking the Driver

You need to compile each driver source file and link the resulting object files into a driver module. The OS is compatible with both the Oracle Solaris Studio C compiler and the GNU C compiler from the Free Software Foundation, Inc. The examples in this section use the Oracle Solaris Studio C compiler unless otherwise noted. For information on the Sun Studio C compiler, see the Sun Studio 12: C User’s Guide and the Sun Studio Documentation. For more information on compile and link options, see the Sun Studio Man Pages. The GNU C compiler is supplied in the /usr/sfw directory. For information on the GNU C compiler, see http://gcc.gnu.org/ or check the man pages in /usr/sfw/man.

The example below shows a driver that is called xx with two C source files. A driver module that is called xx is generated. The driver that is created in this example is for a 32-bit kernel. You must use ld -r even if your driver has only one object module.

% cc -D_KERNEL -c xx1.c
% cc -D_KERNEL -c xx2.c
% ld -r -o xx xx1.o xx2.o

The _KERNEL symbol must be defined to indicate that this code defines a kernel module. No other symbols should be defined, except for driver private symbols. The DEBUG symbol can be defined to enable any calls to ASSERT(9F).

If you are compiling for a 64-bit SPARC architecture using Sun Studio 9, Sun Studio 10, or Sun Studio 11, use the -xarch=v9 option:

% cc -D_KERNEL -xarch=v9 -c xx.c

If you are compiling for a 64-bit SPARC architecture using Sun Studio 12, use the -m64 option:

% cc -D_KERNEL -m64 -c xx.c

If you are compiling for a 64-bit x86 architecture using Sun Studio 10 or Sun Studio 11, use both the -xarch=amd64 option and the -xmodel=kernel option:

% cc -D_KERNEL -xarch=amd64 -xmodel=kernel -c xx.c

If you are compiling for a 64-bit x86 architecture using Sun Studio 12, use the -m64 option, the -xarch=sse2a option, and the -xmodel=kernel option:

% cc -D_KERNEL -m64 -xarch=sse2a -xmodel=kernel -c xx.c

Sun Studio 9 does not support 64-bit x86 architectures. Use Sun Studio 10, Sun Studio 11, or Sun Studio 12 to compile and debug drivers for 64-bit x86 architectures.

After the driver is stable, you might want to add optimization flags to build a production quality driver. See the cc(1) man page in Sun Studio Man Pages for specific information on optimizations in the Sun Studio C compiler.

Global variables should be treated as volatile in device drivers. The volatile tag is discussed in greater detail in Declaring a Variable Volatile. Use of the flag depends on the platform. See the man pages.