NDISCVT(8) BSD System Manager's Manual NDISCVT(8)NAMEndiscvt — convert Windows® NDIS drivers for use with FreeBSD
SYNOPSISndiscvt [-O] [-i inffile] -s sysfile [-n devname] [-o outfile]
ndiscvt [-f firmfile]
The ndiscvt utility transforms a Windows® NDIS driver into a data file
which is used to build an ndis(4) compatibility driver module. Windows®
drivers consist of two main parts: a .SYS file, which contains the actual
driver executable code, and an .INF file, which provides the Windows® in‐
staller with device identifier information and a list of driver-specific
registry keys. The ndiscvt utility can convert these files into a header
file that is compiled into if_ndis.c to create an object code module that
can be linked into the FreeBSD kernel.
The .INF file is typically required since only it contains device identi‐
fication data such as PCI vendor and device IDs or PCMCIA identifier
strings. The .INF file may be optionally omitted however, in which case
the ndiscvt utility will only perform the conversion of the .SYS file.
This is useful for debugging purposes only.
The options are as follows:
Open and parse the specified .INF file when performing conver‐
sion. The ndiscvt utility will parse this file and emit a device
identification structure and registry key configuration struc‐
tures which will be used by the ndis(4) driver and ndisapi(9)
kernel subsystem. If this is omitted, ndiscvt will emit a dummy
configuration structure only.
Open and parse the specified .SYS file. This file must contain a
Windows® driver image. The ndiscvt utility will perform some
manipulation of the sections within the executable file to make
runtime linking within the kernel a little easier and then con‐
vert the image into a data array.
Specify an alternate name for the network device/interface which
will be created when the driver is instantiated. If you need to
load more than one NDIS driver into your system (i.e., if you
have two different network cards in your system which require
NDIS driver support), each module you create must have a unique
name. Device can not be larger than IFNAMSIZ. If no name is
specified, the driver will use the default a default name
Specify the output file in which to place the resulting data.
This can be any file pathname. If outfile is a single dash
(‘-’), the data will be written to the standard output. The
if_ndis.c module expects to find the driver data in a file called
ndis_driver_data.h, so it is recommended that this name be used.
-O Generate both an ndis_driver_data.h file and an
ndis_driver.data.o file. The latter file will contain a copy of
the Windows® .SYS driver image encoded as a FreeBSD ELF object
file (created with objcopy(1)). Turning the Windows® driver
image directly into an object code file saves disk space and com‐
A few NDIS drivers come with additional files that the core
driver module will load during initialization time. Typically,
these files contain firmware which the driver will transfer to
the device in order to make it fully operational. In Windows®,
these files are usually just copied into one of the system direc‐
tories along with the driver itself.
In FreeBSD there are two mechanism for loading these files. If
the driver is built as a loadable kernel module which is loaded
after the kernel has finished booting (and after the root file
system has been mounted), the extra files can simply be copied to
the /compat/ndis directory, and they will be loaded into the ker‐
nel on demand when the the driver needs them.
If however the driver is required to bootstrap the system (i.e.,
if the NDIS-based network interface is to be used for disk‐
less/PXE booting), the files need to be pre-loaded by the boot‐
strap loader in order to be accessible, since the driver will
need them before the root file system has been mounted. However,
the bootstrap loader is only able to load files that are shared
FreeBSD binary objects.
The -f flag can be used to convert an arbitrary file firmfile
into shared object format (the actual conversion is done using
the objcopy(1) and ld(1) commands). The resulting files can then
be copied to the /boot/kernel directory, and can be pre-loaded
directly from the boot loader prompt, or automatically by editing
the loader.conf(5) file. If desired, the files can also be
loaded into memory at runtime using the kldload(8) command.
When an NDIS driver tries to open an external file, the
ndisapi(9) code will first search for a loaded kernel module that
matches the name specified in the open request, and if that
fails, it will then try to open the file from the /compat/ndis
directory as well. Note that during kernel bootstrap, the abil‐
ity to open files from /compat/ndis is disabled: only the module
search will be performed.
When using the -f flag, ndiscvt will generate both a relocatable
object file (with a .o extension) and a shared object file (with
a .ko extension). The shared object is the one that should be
placed in the /boot/kernel directory. The relocatable object
file is useful if the user wishes to create a completely static
kernel image: the object file can be linked into the kernel
directly along with the driver itself. Some editing of the ker‐
nel configuration files will be necessary in order to have the
extra object included in the build.
SEE ALSOld(1), objcopy(1), ndis(4), kldload(8)HISTORY
The ndiscvt utility first appeared in FreeBSD 5.3.
The ndiscvt utility was written by Bill Paul ⟨email@example.com⟩. The
lex(1) and yacc(1) INF file parser was written by Matthew Dodd
BSD December 10, 2003 BSD