/** @file
Device driver for the ChaosKey hardware random number generator.
Copyright (c) 2016 - 2017, Linaro Ltd. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD
License which accompanies this distribution. The full text of the license may
be found at http://opensource.org/licenses/bsd-license.php.
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include <Library/UefiDriverEntryPoint.h>
#include "ChaosKeyDriver.h"
/**
Tests to see if this driver supports a given controller.
@param This[in] A pointer to the EFI_DRIVER_BINDING_PROTOCOL
instance.
@param ControllerHandle[in] The handle of the controller to test.
@param RemainingDevicePath[in] The remaining device path.
(Ignored - this is not a bus driver.)
@retval EFI_SUCCESS The driver supports this controller.
@retval EFI_ALREADY_STARTED The device specified by ControllerHandle is
already being managed by the driver specified
by This.
@retval EFI_UNSUPPORTED The device specified by ControllerHandle is
not supported by the driver specified by This.
**/
EFI_STATUS
EFIAPI
UsbHwrngDriverBindingSupported (
IN EFI_DRIVER_BINDING_PROTOCOL *This,
IN EFI_HANDLE ControllerHandle,
IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
)
{
EFI_USB_DEVICE_DESCRIPTOR Device;
EFI_USB_IO_PROTOCOL *UsbIo;
EFI_STATUS Status;
//
// Connect to the USB stack
//
Status = gBS->OpenProtocol (ControllerHandle,
&gEfiUsbIoProtocolGuid,
(VOID **) &UsbIo,
This->DriverBindingHandle,
ControllerHandle,
EFI_OPEN_PROTOCOL_BY_DRIVER);
if (EFI_ERROR (Status)) {
return Status;
}
//
// Get the interface descriptor to check the USB class and find a transport
// protocol handler.
//
Status = UsbIo->UsbGetDeviceDescriptor (UsbIo, &Device);
if (!EFI_ERROR (Status)) {
//
// Validate the adapter
//
if ((Device.IdVendor != CHAOSKEY_VENDOR_ID) ||
(Device.IdProduct != CHAOSKEY_PRODUCT_ID)) {
Status = EFI_UNSUPPORTED;
} else {
DEBUG ((DEBUG_INIT | DEBUG_INFO,
"Detected ChaosKey RNG device (USB VendorID:0x%04x ProductID:0x%04x)\n",
Device.IdVendor, Device.IdProduct));
Status = EFI_SUCCESS;
}
}
//
// Clean up.
//
gBS->CloseProtocol (ControllerHandle,
&gEfiUsbIoProtocolGuid,
This->DriverBindingHandle,
ControllerHandle);
return Status;
}
/**
Starts a device controller or a bus controller.
@param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL
instance.
@param[in] ControllerHandle The handle of the device to start. This
handle must support a protocol interface that
supplies an I/O abstraction to the driver.
@param[in] RemainingDevicePath The remaining portion of the device path.
(Ignored - this is not a bus driver.)
@retval EFI_SUCCESS The device was started.
@retval EFI_DEVICE_ERROR The device could not be started due to a
device error.
@retval EFI_OUT_OF_RESOURCES The request could not be completed due to a
lack of resources.
**/
EFI_STATUS
EFIAPI
UsbHwrngDriverBindingStart (
IN EFI_DRIVER_BINDING_PROTOCOL *This,
IN EFI_HANDLE ControllerHandle,
IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath OPTIONAL
)
{
return ChaosKeyInit (This->DriverBindingHandle, ControllerHandle);
}
/**
Stops a device controller or a bus controller.
@param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL
instance.
@param[in] ControllerHandle A handle to the device being stopped. The handle
must support a bus specific I/O protocol for the
driver to use to stop the device.
@param[in] NumberOfChildren The number of child device handles in
ChildHandleBuffer.
@param[in] ChildHandleBuffer An array of child handles to be freed. May be
NULL if NumberOfChildren is 0.
@retval EFI_SUCCESS The device was stopped.
@retval EFI_DEVICE_ERROR The device could not be stopped due to a device
error.
**/
EFI_STATUS
EFIAPI
UsbHwrngDriverBindingStop (
IN EFI_DRIVER_BINDING_PROTOCOL *This,
IN EFI_HANDLE ControllerHandle,
IN UINTN NumberOfChildren,
IN EFI_HANDLE *ChildHandleBuffer OPTIONAL
)
{
return ChaosKeyRelease (This->DriverBindingHandle, ControllerHandle);
}
STATIC
EFI_DRIVER_BINDING_PROTOCOL gUsbDriverBinding = {
UsbHwrngDriverBindingSupported,
UsbHwrngDriverBindingStart,
UsbHwrngDriverBindingStop,
0xa,
NULL,
NULL
};
/**
The entry point of ChaosKey UEFI Driver.
@param ImageHandle The image handle of the UEFI Driver.
@param SystemTable A pointer to the EFI System Table.
@retval EFI_SUCCESS The Driver or UEFI Driver exited normally.
@retval EFI_INCOMPATIBLE_VERSION _gUefiDriverRevision is greater than
SystemTable->Hdr.Revision.
**/
EFI_STATUS
EFIAPI
EntryPoint (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
//
// Add the driver to the list of drivers
//
Status = EfiLibInstallDriverBindingComponentName2 (
ImageHandle, SystemTable, &gUsbDriverBinding, ImageHandle,
NULL, &gChaosKeyDriverComponentName2);
ASSERT_EFI_ERROR (Status);
DEBUG ((DEBUG_INIT | DEBUG_INFO, "*** Installed ChaosKey driver! ***\n"));
return EFI_SUCCESS;
}
/**
Unload function for the ChaosKey Driver.
@param ImageHandle[in] The allocated handle for the EFI image
@retval EFI_SUCCESS The driver was unloaded successfully
@retval EFI_INVALID_PARAMETER ImageHandle is not a valid image handle.
**/
EFI_STATUS
EFIAPI
UnloadImage (
IN EFI_HANDLE ImageHandle
)
{
EFI_STATUS Status;
EFI_HANDLE *HandleBuffer;
UINTN HandleCount;
UINTN Index;
//
// Retrieve all USB I/O handles in the handle database
//
Status = gBS->LocateHandleBuffer (ByProtocol,
&gEfiUsbIoProtocolGuid,
NULL,
&HandleCount,
&HandleBuffer);
if (EFI_ERROR (Status)) {
return Status;
}
//
// Disconnect the driver from the handles in the handle database
//
for (Index = 0; Index < HandleCount; Index++) {
Status = gBS->DisconnectController (HandleBuffer[Index],
gImageHandle,
NULL);
}
//
// Free the handle array
//
gBS->FreePool (HandleBuffer);
//
// Uninstall protocols installed by the driver in its entrypoint
//
Status = gBS->UninstallMultipleProtocolInterfaces (ImageHandle,
&gEfiDriverBindingProtocolGuid,
&gUsbDriverBinding,
NULL
);
return EFI_SUCCESS;
}