when we create a PDO, the driver_object associated with it is that
of the parent driver, not the driver we're trying to attach. For
example, if we attach a PCI device, the PDO we pass to the NdisAddDevice()
function should contain a pointer to fake_pci_driver, not to the NDIS
driver itself. For PCI or PCMCIA devices this doesn't matter because
the child never needs to talk to the parent bus driver, but for USB,
the child needs to be able to send IRPs to the parent USB bus driver, and
for that to work the parent USB bus driver has to be hung off the PDO.
This involves modifying windrv_lookup() so that we can search for
bus drivers by name, if necessary. Our fake bus drivers attach themselves
as "PCI Bus," "PCCARD Bus" and "USB Bus," so we can search for them
using those names.
The individual attachment stubs now create and attach PDOs to the
parent bus drivers instead of hanging them off the NDIS driver's
object, and in if_ndis.c, we now search for the correct driver
object depending on the bus type, and use that to find the correct PDO.
With this fix, I can get my sample USB ethernet driver to deliver
an IRP to my fake parent USB bus driver's dispatch routines.
- Add stub modules for USB support: subr_usbd.c, usbd_var.h and
if_ndis_usb.c. The subr_usbd.c module is hooked up the build
but currently doesn't do very much. It provides the stub USB
parent driver object and a dispatch routine for
IRM_MJ_INTERNAL_DEVICE_CONTROL. The only exported function at
the moment is USBD_GetUSBDIVersion(). The if_ndis_usb.c stub
compiles, but is not hooked up to the build yet. I'm putting
these here so I can keep them under source code control as I
flesh them out.
Windows DRIVER_OBJECT and DEVICE_OBJECT mechanism so that we can
simulate driver stacking.
In Windows, each loaded driver image is attached to a DRIVER_OBJECT
structure. Windows uses the registry to match up a given vendor/device
ID combination with a corresponding DRIVER_OBJECT. When a driver image
is first loaded, its DriverEntry() routine is invoked, which sets up
the AddDevice() function pointer in the DRIVER_OBJECT and creates
a dispatch table (based on IRP major codes). When a Windows bus driver
detects a new device, it creates a Physical Device Object (PDO) for
it. This is a DEVICE_OBJECT structure, with semantics analagous to
that of a device_t in FreeBSD. The Windows PNP manager will invoke
the driver's AddDevice() function and pass it pointers to the DRIVER_OBJECT
and the PDO.
The AddDevice() function then creates a new DRIVER_OBJECT structure of
its own. This is known as the Functional Device Object (FDO) and
corresponds roughly to a private softc instance. The driver uses
IoAttachDeviceToDeviceStack() to add this device object to the
driver stack for this PDO. Subsequent drivers (called filter drivers
in Windows-speak) can be loaded which add themselves to the stack.
When someone issues an IRP to a device, it travel along the stack
passing through several possible filter drivers until it reaches
the functional driver (which actually knows how to talk to the hardware)
at which point it will be completed. This is how Windows achieves
driver layering.
Project Evil now simulates most of this. if_ndis now has a modevent
handler which will use MOD_LOAD and MOD_UNLOAD events to drive the
creation and destruction of DRIVER_OBJECTs. (The load event also
does the relocation/dynalinking of the image.) We don't have a registry,
so the DRIVER_OBJECTS are stored in a linked list for now. Eventually,
the list entry will contain the vendor/device ID list extracted from
the .INF file. When ndis_probe() is called and detectes a supported
device, it will create a PDO for the device instance and attach it
to the DRIVER_OBJECT just as in Windows. ndis_attach() will then call
our NdisAddDevice() handler to create the FDO. The NDIS miniport block
is now a device extension hung off the FDO, just as it is in Windows.
The miniport characteristics table is now an extension hung off the
DRIVER_OBJECT as well (the characteristics are the same for all devices
handled by a given driver, so they don't need to be per-instance.)
We also do an IoAttachDeviceToDeviceStack() to put the FDO on the
stack for the PDO. There are a couple of fake bus drivers created
for the PCI and pccard buses. Eventually, there will be one for USB,
which will actually accept USB IRP.s
Things should still work just as before, only now we do things in
the proper order and maintain the correct framework to support passing
IRPs between drivers.
Various changes:
- corrected the comments about IRQL handling in subr_hal.c to more
accurately reflect reality
- update ndiscvt to make the drv_data symbol in ndis_driver_data.h a
global so that if_ndis_pci.o and/or if_ndis_pccard.o can see it.
- Obtain the softc pointer from the miniport block by referencing
the PDO rather than a private pointer of our own (nmb_ifp is no
longer used)
- implement IoAttachDeviceToDeviceStack(), IoDetachDevice(),
IoGetAttachedDevice(), IoAllocateDriverObjectExtension(),
IoGetDriverObjectExtension(), IoCreateDevice(), IoDeleteDevice(),
IoAllocateIrp(), IoReuseIrp(), IoMakeAssociatedIrp(), IoFreeIrp(),
IoInitializeIrp()
- fix a few mistakes in the driver_object and device_object definitions
- add a new module, kern_windrv.c, to handle the driver registration
and relocation/dynalinkign duties (which don't really belong in
kern_ndis.c).
- made ndis_block and ndis_chars in the ndis_softc stucture pointers
and modified all references to it
- fixed NdisMRegisterMiniport() and NdisInitializeWrapper() so they
work correctly with the new driver_object mechanism
- changed ndis_attach() to call NdisAddDevice() instead of ndis_load_driver()
(which is now deprecated)
- used ExAllocatePoolWithTag()/ExFreePool() in lookaside list routines
instead of kludged up alloc/free routines
- added kern_windrv.c to sys/modules/ndis/Makefile and files.i386.
This was tested with a Netgear WG311v2 802.11b/g PCI card. Things
that were fixed:
- This chip has two memory mapped regions, one at PCIR_BAR(0) and the
other at PCIR_BAR(1). This is a little different from the other
chips I've seen with two PCI shared memory regions, since they tend
to have the second BAR ad PCIR_BAR(2). if_ndis_pci.c tests explicitly
for PCIR_BAR(2). This has been changed to simply fill in ndis_res_mem
first and ndis_res_altmem second, if a second shared memory range
exists. Given that NDIS drivers seem to scan for BARs in ascending
order, I think this should be ok.
- Fixed the code that tries to process firmware images that have been
loaded as .ko files. To save a step, I was setting up the address
mapping in ndis_open_file(), but ndis_map_file() flags pre-existing
mappings as an error (to avoid duplicate mappings). Changed this so
that the mapping is now donw in ndis_map_file() as expected.
- Made the typedef for 'driver_entry' explicitly include __stdcall
to silence gcc warning in ndis_load_driver().
NOTE: the Texas Instruments ACX111 driver needs firmware. With my
card, there were 3 .bin files shipped with the driver. You must
either put these files in /compat/ndis or convert them with
ndiscvt -f and kldload them so the driver can use them. Without
the firmware image, the NIC won't work.
actually work.
Make the PCI and PCCARD attachments provide a bus_get_resource_list()
method so that resource listing for PCCARD works. PCCARD does not
have a bus_get_resource_list() method (yet), so I faked up the
resource list management in if_ndis_pccard.c, and added
bus_get_resource_list() methods to both if_ndis_pccard.c and if_ndis_pci.c.
The one in the PCI attechment just hands off to the PCI bus code.
The difference is transparent to the NDIS resource handler code.
Fixed ndis_open_file() so that opening files which live on NFS
filesystems work: pass an actual ucred structure to VOP_GETATTR()
(NFS explodes if the ucred structure is NOCRED).
Make NdisMMapIoSpace() handle mapping of PCMCIA attribute memory
resources correctly.
Turn subr_ndis.c:my_strcasecmp() into ndis_strcasecmp() and export
it so that if_ndis_pccard.c can use it, and junk the other copy
of my_strcasecmp() from if_ndis_pccard.c.
instead of bus_alloc_resource_any() to restore source compatibility
with 5.2-REL and 5.2.1-REL systems. bus_alloc_resource_any() doesn't
really do anything besides hide some of bus_alloc_resource()'s arguments
from us, and in my opinion this isn't worth breaking backwards
compatibility for people who want to use the NDISulator code on 5.2.x.
ndis_probe_pci() doesn't contain an entry for an IRQ resource, try to
force one to be routed to us anyway by adding an extra call to
bus_alloc_resource(). If this fails, then we have to abort the attach.
Patch provided by jhb, tweaked by me.
if_ndis.c has been split into if_ndis_pci.c and if_ndis_pccard.c.
The ndiscvt(8) utility should be able to parse device info for PCMCIA
devices now. The ndis_alloc_amem() has moved from kern_ndis.c to
if_ndis_pccard.c so that kern_ndis.c no longer depends on pccard.
NOTE: this stuff is not guaranteed to work 100% correctly yet. So
far I have been able to load/init my PCMCIA Cisco Aironet 340 card,
but it crashes in the interrupt handler. The existing support for
PCI/cardbus devices should still work as before.
