Re: [PATCH edk2-platforms] Silicon/Openmoko: add driver for ChaosKey RNG USB device

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 24 August 2017 at 00:48, Leif Lindholm <leif.lindholm@linaro.org> wrote:
> On Wed, Aug 23, 2017 at 02:12:06PM +0100, Ard Biesheuvel wrote:
>> This is a continuation of the work carried out by Leif Lindholm to
>> implement a driver for the ChaosKey USB device. This driver uses the
>> UEFI driver model, which is a slightly awkward fit, due to the fact
>> that a UEFI implementation may legally only instantiate those protocols
>> that are needed to access the device path that the active Boot####
>> options refers to.
>>
>> However, it is expected that UEFI implementations typically instantiate
>> all USB I/O protocols and connect them as well, as those are required
>> for a USB keyboard to be able to control the boot sequence. This should
>> result in this driver being connected and given the opportunity to
>> produce the EFI_RNG_PROTOCOL.
>>
>> Contributed-under: TianoCore Contribution Agreement 1.1
>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> ---
>>  Silicon/Openmoko/ChaosKeyDxe/ChaosKeyDriver.c | 346 ++++++++++++++++++++
>>  Silicon/Openmoko/ChaosKeyDxe/ChaosKeyDriver.h |  61 ++++
>>  Silicon/Openmoko/ChaosKeyDxe/ChaosKeyDxe.inf  |  48 +++
>>  Silicon/Openmoko/ChaosKeyDxe/ComponentName.c  | 205 ++++++++++++
>>  Silicon/Openmoko/ChaosKeyDxe/DriverBinding.c  | 256 +++++++++++++++
>>  5 files changed, 916 insertions(+)
>
> This is all a bit new territory, so I don't know what the best way of
> dealing with this is, but I think we could do with a .dsc somewhere to
> enable building this driver standalone. My gut feel is that an
> Openmoko/Openmoko.dsc would be a reasonable candidate.
>

Yeah, I can add one. Also useful for building this driver as an EBC binary.

>> diff --git a/Silicon/Openmoko/ChaosKeyDxe/ChaosKeyDriver.c b/Silicon/Openmoko/ChaosKeyDxe/ChaosKeyDriver.c
>> new file mode 100644
>> index 000000000000..1870080d2c70
>> --- /dev/null
>> +++ b/Silicon/Openmoko/ChaosKeyDxe/ChaosKeyDriver.c
>> @@ -0,0 +1,346 @@
>> +/** @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 "ChaosKeyDriver.h"
>> +
>> +#include <Library/BaseMemoryLib.h>
>> +#include <Library/DebugLib.h>
>> +#include <Library/MemoryAllocationLib.h>
>> +
>> +STATIC
>> +BOOLEAN
>> +IsBulkInEndpoint (
>> +  IN  EFI_USB_ENDPOINT_DESCRIPTOR     *Endpoint
>> +  )
>> +{
>> +  if ((Endpoint->Attributes & USB_ENDPOINT_TYPE_MASK) == USB_ENDPOINT_BULK) {
>> +    if (Endpoint->EndpointAddress & USB_ENDPOINT_DIR_IN) {
>> +      return TRUE;
>> +    }
>> +  }
>> +  return FALSE;
>> +}
>> +
>> +
>> +STATIC
>> +EFI_STATUS
>> +FindEndpoint (
>> +  IN  CHAOSKEY_DEV *ChaosKey
>> +  )
>> +{
>> +  EFI_USB_IO_PROTOCOL             *UsbIo;
>> +  EFI_STATUS                      Status;
>> +  UINTN                           Index;
>> +  EFI_USB_INTERFACE_DESCRIPTOR    InterfaceDescriptor;
>> +
>> +  UsbIo = ChaosKey->UsbIo;
>> +
>> +  //
>> +  // Get interface & endpoint descriptor
>> +  //
>> +  Status = UsbIo->UsbGetInterfaceDescriptor (UsbIo, &InterfaceDescriptor);
>> +  if (EFI_ERROR (Status)) {
>> +    return Status;
>> +  }
>> +
>> +  //
>> +  // The ChaosKey provides two endpoints:
>> +  // - The first one is the 'cooked' one, to be used as random data input
>> +  // - The second one is the raw bitstream from the generator, higher
>> +  //   throughput, but lower randomness.
>> +  // So locate the first bulk IN endpoint and save it for later use.
>> +  //
>> +  for (Index = 0; Index < InterfaceDescriptor.NumEndpoints; Index++) {
>> +    EFI_USB_ENDPOINT_DESCRIPTOR  Endpoint;
>> +
>> +    Status = UsbIo->UsbGetEndpointDescriptor (UsbIo, Index, &Endpoint);
>> +    if (EFI_ERROR (Status)) {
>> +      DEBUG ((DEBUG_ERROR, "UsbGetEndPointDescriptor(%d) failed!\n", Index));
>> +      return Status;
>> +    }
>> +
>> +    if (IsBulkInEndpoint(&Endpoint)) {
>> +      ChaosKey->EndpointAddress = Endpoint.EndpointAddress;
>> +      ChaosKey->EndpointSize = Endpoint.MaxPacketSize;
>> +      return EFI_SUCCESS;
>> +    }
>> +  }
>> +
>> +  DEBUG ((DEBUG_ERROR, "Failed to locate suitable BULK IN USB endpoint!\n"));
>> +  return EFI_DEVICE_ERROR;
>> +}
>> +
>> +
>> +/**
>> +  Returns information about the random number generation implementation.
>> +
>> +  @param[in]     This               A pointer to the EFI_RNG_PROTOCOL instance.
>> +  @param[in,out] AlgorithmListSize  On input, the size in bytes of AlgorithmList
>> +                                    On output with a return code of EFI_SUCCESS,
>> +                                    the size in bytes of the data returned in
>> +                                    AlgorithmList. On output with a return
>> +                                    code of EFI_BUFFER_TOO_SMALL, the size of
>> +                                    AlgorithmList required to obtain the list.
>> +  @param[out] AlgorithmList         A caller-allocated memory buffer filled by
>> +                                    the driver with one EFI_RNG_ALGORITHM
>> +                                    element for each supported RNG algorithm.
>> +                                    The list must not change across multiple
>> +                                    calls to the same driver. The first
>> +                                    algorithm in the list is the default
>> +                                    algorithm for the driver.
>> +
>> +  @retval EFI_SUCCESS               The RNG algorithm list was returned
>> +                                    successfully.
>> +  @retval EFI_UNSUPPORTED           The services is not supported by this driver
>> +  @retval EFI_DEVICE_ERROR          The list of algorithms could not be
>> +                                    retrieved due to a hardware or firmware
>> +                                    error.
>> +  @retval EFI_INVALID_PARAMETER     One or more of the parameters are incorrect.
>> +  @retval EFI_BUFFER_TOO_SMALL      The buffer RNGAlgorithmList is too small to
>> +                                    hold the result.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +EFIAPI
>> +GetInfo (
>> +  IN      EFI_RNG_PROTOCOL    *This,
>> +  IN  OUT UINTN               *AlgorithmListSize,
>> +  OUT     EFI_RNG_ALGORITHM   *AlgorithmList
>> +)
>> +{
>> +  UINTN Size;
>> +
>> +  //
>> +  // We only implement the raw algorithm
>> +  //
>> +  Size = sizeof gEfiRngAlgorithmRaw;
>> +
>> +  if (*AlgorithmListSize < Size) {
>> +    *AlgorithmListSize = Size;
>> +    return EFI_BUFFER_TOO_SMALL;
>> +  }
>> +
>> +  gBS->CopyMem (AlgorithmList, &gEfiRngAlgorithmRaw, Size);
>> +  *AlgorithmListSize = Size;
>> +
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +
>> +/**
>> +  Produces and returns an RNG value using either the default or specified RNG
>> +  algorithm.
>> +
>> +  @param[in]  This                A pointer to the EFI_RNG_PROTOCOL instance.
>> +  @param[in]  Algorithm           A pointer to the EFI_RNG_ALGORITHM that
>> +                                  identifies the RNG algorithm to use. May be
>> +                                  NULL in which case the function will use its
>> +                                  default RNG algorithm.
>> +  @param[in]  ValueLength         The length in bytes of the memory buffer
>> +                                  pointed to by RNGValue. The driver shall
>> +                                  return exactly this numbers of bytes.
>> +  @param[out] Value               A caller-allocated memory buffer filled by the
>> +                                  driver with the resulting RNG value.
>> +
>> +  @retval EFI_SUCCESS             The RNG value was returned successfully.
>> +  @retval EFI_UNSUPPORTED         The algorithm specified by RNGAlgorithm is not
>> +                                  supported by this driver.
>> +  @retval EFI_DEVICE_ERROR        An RNG value could not be retrieved due to a
>> +                                  hardware or firmware error.
>> +  @retval EFI_NOT_READY           There is not enough random data available to
>> +                                  satisfy the length requested by
>> +                                  RNGValueLength.
>> +  @retval EFI_INVALID_PARAMETER   RNGValue is NULL or RNGValueLength is zero.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +EFIAPI
>> +GetRNG (
>> +  IN EFI_RNG_PROTOCOL   *This,
>> +  IN EFI_RNG_ALGORITHM  *Algorithm OPTIONAL,
>> +  IN UINTN              ValueLength,
>> +  OUT UINT8             *Value
>> +)
>> +{
>> +  EFI_STATUS        Status;
>> +  CHAOSKEY_DEV      *ChaosKey;
>> +  EFI_TPL           Tpl;
>> +  UINT8             Buffer[CHAOSKEY_MAX_EP_SIZE];
>> +  UINT8             *OutPointer;
>> +  UINTN             OutSize;
>> +  UINT32            Result;
>> +
>> +  if (Algorithm != NULL && !CompareGuid (Algorithm, &gEfiRngAlgorithmRaw)) {
>> +    return EFI_UNSUPPORTED;
>> +  }
>> +
>> +  ChaosKey = CHAOSKEY_DEV_FROM_THIS (This);
>> +
>> +  while (ValueLength > 0) {
>> +    //
>> +    // If more data is requested than the endpoint can deliver in a single
>> +    // transfer, put it straight into the caller's buffer.
>> +    //
>> +    if (ValueLength >= ChaosKey->EndpointSize) {
>> +      OutPointer = Value;
>> +    } else {
>> +      OutPointer = Buffer;
>> +    }
>> +    OutSize = ChaosKey->EndpointSize;
>> +
>> +    Tpl = gBS->RaiseTPL (TPL_NOTIFY);
>
> You mentioned to me on IRC that this should not be necessary, and that
> UsbIo should adjust tpl as necessary.
>
> It is quite likely I misinterpreted behaviour I encountered when using
> USB passthrough in QEMU for testing (and managed to break the host
> system's driver).
>

I will remove it. We are dealing with an abstract protocol here, not
hardware, and if completing a single bulk transfer does not tolerate
interruptions, it should be up to the USB I/O protocol implementation
to deal with that.

>> +
>> +    Status = ChaosKey->UsbIo->UsbBulkTransfer (ChaosKey->UsbIo,
>> +                                               ChaosKey->EndpointAddress,
>> +                                               OutPointer,
>> +                                               &OutSize,
>> +                                               CHAOSKEY_TIMEOUT,
>> +                                               &Result);
>> +
>> +    gBS->RestoreTPL (Tpl);
>> +
>> +    if (Status == EFI_TIMEOUT) {
>> +      DEBUG ((DEBUG_ERROR, "Bulk transfer timed out, USB status == %d\n",
>> +        Result));
>> +      return EFI_NOT_READY;
>> +    } else if (EFI_ERROR (Status)) {
>> +      DEBUG ((DEBUG_ERROR,
>> +        "Bulk transfer failed, Status == %r, USB status == %d\n",
>> +        Status, Result));
>> +      return EFI_DEVICE_ERROR;
>> +    }
>> +
>> +    OutSize = MIN (OutSize, ValueLength);
>> +
>> +    if (Value != Buffer) {
>> +      gBS->CopyMem (Value, Buffer, OutSize);
>> +    }
>> +    Value += OutSize;
>> +    ValueLength -= OutSize;
>> +  }
>> +  return EFI_SUCCESS;
>> +}
>> +
>> +
>> +EFI_STATUS
>> +ChaosKeyInit (
>> +  IN      EFI_HANDLE        DriverBindingHandle,
>> +  IN      EFI_HANDLE        ControllerHandle
>> +  )
>> +{
>> +  EFI_STATUS                Status;
>> +  CHAOSKEY_DEV              *ChaosKey;
>> +
>> +  Status  = gBS->AllocatePool (EfiBootServicesData,
>> +                               sizeof (CHAOSKEY_DEV),
>> +                               (VOID **) &ChaosKey);
>> +  if (EFI_ERROR (Status)) {
>> +    return EFI_OUT_OF_RESOURCES;
>> +  }
>> +
>> +  ChaosKey->Signature         = CHAOSKEY_DEV_SIGNATURE;
>> +  ChaosKey->Rng.GetInfo       = GetInfo;
>> +  ChaosKey->Rng.GetRNG        = GetRNG;
>> +
>> +  //
>> +  // Open USB I/O Protocol
>> +  //
>> +  Status = gBS->OpenProtocol (ControllerHandle,
>> +                              &gEfiUsbIoProtocolGuid,
>> +                              (VOID **)&ChaosKey->UsbIo,
>> +                              DriverBindingHandle,
>> +                              ControllerHandle,
>> +                              EFI_OPEN_PROTOCOL_BY_DRIVER);
>> +  if (EFI_ERROR (Status)) {
>> +    goto ErrorFreeDev;
>> +  }
>> +
>> +  Status = FindEndpoint (ChaosKey);
>> +  if (EFI_ERROR (Status)) {
>> +    goto ErrorCloseProtocol;
>> +  }
>> +
>> +  //
>> +  // The following can only occur if the Chaoskey is suddenly reissued
>> +  // as a high speed or super speed device under the same VID/PID.
>> +  //
>> +  ASSERT (ChaosKey->EndpointSize <= CHAOSKEY_MAX_EP_SIZE);
>> +
>> +  Status = gBS->InstallProtocolInterface (&ControllerHandle,
>> +                                          &gEfiRngProtocolGuid,
>> +                                          EFI_NATIVE_INTERFACE,
>> +                                          &ChaosKey->Rng);
>> +  if (EFI_ERROR (Status)) {
>> +    DEBUG ((DEBUG_ERROR,
>> +      "Failed to install RNG protocol interface (Status == %r)\n",
>> +    Status));
>> +    goto ErrorCloseProtocol;
>> +  }
>> +
>> +  return EFI_SUCCESS;
>> +
>> +ErrorCloseProtocol:
>> +  gBS->CloseProtocol (ControllerHandle, &gEfiUsbIoProtocolGuid,
>> +         DriverBindingHandle, ControllerHandle);
>> +
>> +ErrorFreeDev:
>> +  gBS->FreePool (ChaosKey);
>> +
>> +  return Status;
>> +}
>> +
>> +EFI_STATUS
>> +ChaosKeyRelease (
>> +  IN  EFI_HANDLE        DriverBindingHandle,
>> +  IN  EFI_HANDLE        ControllerHandle
>> +  )
>> +{
>> +  EFI_RNG_PROTOCOL    *Rng;
>> +  CHAOSKEY_DEV        *ChaosKey;
>> +  EFI_STATUS          Status;
>> +
>> +  Status = gBS->HandleProtocol (ControllerHandle,
>> +                                &gEfiRngProtocolGuid,
>> +                                (VOID **)&Rng);
>> +  ASSERT_EFI_ERROR (Status);
>> +  if (EFI_ERROR (Status)) {
>> +    return Status;
>> +  }
>> +
>> +  ChaosKey = CHAOSKEY_DEV_FROM_THIS (Rng);
>> +
>> +  Status = gBS->UninstallProtocolInterface (ControllerHandle,
>> +                                            &gEfiRngProtocolGuid,
>> +                                            Rng);
>> +  ASSERT_EFI_ERROR (Status);
>> +  if (EFI_ERROR (Status)) {
>> +    return Status;
>> +  }
>> +
>> +  Status = gBS->CloseProtocol (ControllerHandle,
>> +                               &gEfiUsbIoProtocolGuid,
>> +                               DriverBindingHandle,
>> +                               ControllerHandle);
>> +  ASSERT_EFI_ERROR (Status);
>> +  if (EFI_ERROR (Status)) {
>> +    return Status;
>> +  }
>> +
>> +  gBS->FreePool (ChaosKey);
>> +
>> +  return EFI_SUCCESS;
>> +}
>> diff --git a/Silicon/Openmoko/ChaosKeyDxe/ChaosKeyDriver.h b/Silicon/Openmoko/ChaosKeyDxe/ChaosKeyDriver.h
>> new file mode 100644
>> index 000000000000..153deb4edb1c
>> --- /dev/null
>> +++ b/Silicon/Openmoko/ChaosKeyDxe/ChaosKeyDriver.h
>> @@ -0,0 +1,61 @@
>> +/** @file
>> +  Header file 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.
>> +
>> +**/
>> +
>> +#ifndef _CHAOSKEY_USB_HWRNG_DRIVER_H_
>> +#define _CHAOSKEY_USB_HWRNG_DRIVER_H_
>> +
>> +#include <Uefi.h>
>> +#include <Library/DebugLib.h>
>> +#include <Library/UefiLib.h>
>> +#include <Library/UefiBootServicesTableLib.h>
>
> B before L.
>

OK

>> +
>> +#include <Protocol/Rng.h>
>> +#include <Protocol/UsbIo.h>
>> +
>> +#define CHAOSKEY_VENDOR_ID      0x1d50  /* OpenMoko */
>> +#define CHAOSKEY_PRODUCT_ID     0x60c6  /* ChaosKey */
>> +
>> +#define CHAOSKEY_TIMEOUT        10 // ms
>> +#define CHAOSKEY_MAX_EP_SIZE    64 // max EP size for full-speed devices
>> +
>> +#define CHAOSKEY_DEV_SIGNATURE  SIGNATURE_32('c','h','k','e')
>> +
>> +typedef struct {
>> +  UINT32                        Signature;
>> +  UINT16                        EndpointAddress;
>> +  UINT16                        EndpointSize;
>> +  EFI_USB_IO_PROTOCOL           *UsbIo;
>> +  EFI_RNG_PROTOCOL              Rng;
>> +} CHAOSKEY_DEV;
>> +
>> +#define CHAOSKEY_DEV_FROM_THIS(a) \
>> +  CR(a, CHAOSKEY_DEV, Rng, CHAOSKEY_DEV_SIGNATURE)
>> +
>> +extern EFI_COMPONENT_NAME_PROTOCOL gChaosKeyDriverComponentName;
>> +extern EFI_COMPONENT_NAME2_PROTOCOL gChaosKeyDriverComponentName2;
>> +
>> +EFI_STATUS
>> +ChaosKeyInit (
>> +  IN  EFI_HANDLE        DriverBindingHandle,
>> +  IN  EFI_HANDLE        ControllerHandle
>> +  );
>> +
>> +EFI_STATUS
>> +ChaosKeyRelease (
>> +  IN  EFI_HANDLE        DriverBindingHandle,
>> +  IN  EFI_HANDLE        ControllerHandle
>> +  );
>> +
>> +#endif // _CHAOSKEY_USB_HWRNG_DRIVER_H_
>> diff --git a/Silicon/Openmoko/ChaosKeyDxe/ChaosKeyDxe.inf b/Silicon/Openmoko/ChaosKeyDxe/ChaosKeyDxe.inf
>> new file mode 100644
>> index 000000000000..2ff84956ca72
>> --- /dev/null
>> +++ b/Silicon/Openmoko/ChaosKeyDxe/ChaosKeyDxe.inf
>> @@ -0,0 +1,48 @@
>> +## @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.
>> +#
>> +##
>> +
>> +[Defines]
>> +  INF_VERSION                    = 0x00010019
>> +  BASE_NAME                      = ChaosKeyDxe
>> +  FILE_GUID                      = 9A54122B-F5E4-40D8-AE61-A71E406ED449
>> +  MODULE_TYPE                    = UEFI_DRIVER
>> +  VERSION_STRING                 = 1.0
>> +  ENTRY_POINT                    = EntryPoint
>> +  UNLOAD_IMAGE                   = UnloadImage
>> +
>> +#
>> +#  VALID_ARCHITECTURES           = AARCH64 ARM EBC IA32 IPF X64
>> +#
>> +
>> +[Sources]
>> +  ChaosKeyDriver.c
>> +  ChaosKeyDriver.h
>> +  ComponentName.c
>> +  DriverBinding.c
>> +
>> +[Packages]
>> +  MdePkg/MdePkg.dec
>> +
>> +[LibraryClasses]
>> +  UefiBootServicesTableLib
>> +  UefiDriverEntryPoint
>> +  UefiLib
>> +
>> +[Protocols]
>> +  gEfiRngProtocolGuid                 # PROTOCOL BY_START
>> +  gEfiUsbIoProtocolGuid               # PROTOCOL TO_START
>> +
>> +[Guids]
>> +  gEfiRngAlgorithmRaw
>> diff --git a/Silicon/Openmoko/ChaosKeyDxe/ComponentName.c b/Silicon/Openmoko/ChaosKeyDxe/ComponentName.c
>> new file mode 100644
>> index 000000000000..81f2130bcd9e
>> --- /dev/null
>> +++ b/Silicon/Openmoko/ChaosKeyDxe/ComponentName.c
>
> You mentioned on IRC that there's an accidental incomplete refactoring
> in this file (and indeed the build fails as it stands).
>
>> @@ -0,0 +1,205

Yes.

 @@
>> +/** @file
>> +  UEFI Component Name(2) protocol implementation for ChaosKey driver.
>> +
>> +  Copyright (c) 2017, Linaro Ltd. All rights reserved.
>> +
>> +  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 "ChaosKeyDriver.h"
>> +
>> +STATIC EFI_UNICODE_STRING_TABLE mChaosKeyDriverNameTable[] = {
>> +  {
>> +    "eng;en",
>> +    (CHAR16 *)L"ChaosKey RNG USB driver"
>> +  },
>> +  {
>> +    NULL,
>> +    NULL
>> +  }
>> +};
>> +
>> +STATIC EFI_UNICODE_STRING_TABLE mChaosKeyControllerNameTable[] = {
>> +  {
>> +    "eng;en",
>> +    (CHAR16 *)L"ChaosKey Random Number Generator (USB)"
>> +  },
>> +  {
>> +    NULL,
>> +    NULL
>> +  }
>> +};
>> +
>> +/**
>> +  Retrieves a Unicode string that is the user readable name of the driver.
>> +
>> +  This function retrieves the user readable name of a driver in the form of a
>> +  Unicode string. If the driver specified by This has a user readable name in
>> +  the language specified by Language, then a pointer to the driver name is
>> +  returned in DriverName, and EFI_SUCCESS is returned. If the driver specified
>> +  by This does not support the language specified by Language,
>> +  then EFI_UNSUPPORTED is returned.
>> +
>> +  @param  This[in]              A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or
>> +                                EFI_COMPONENT_NAME_PROTOCOL instance.
>> +
>> +  @param  Language[in]          A pointer to a Null-terminated ASCII string
>> +                                array indicating the language. This is the
>> +                                language of the driver name that the caller is
>> +                                requesting, and it must match one of the
>> +                                languages specified in SupportedLanguages. The
>> +                                number of languages supported by a driver is up
>> +                                to the driver writer. Language is specified
>> +                                in RFC 4646 or ISO 639-2 language code format.
>> +
>> +  @param  DriverName[out]       A pointer to the Unicode string to return.
>> +                                This Unicode string is the name of the
>> +                                driver specified by This in the language
>> +                                specified by Language.
>> +
>> +  @retval EFI_SUCCESS           The Unicode string for the Driver specified by
>> +                                This and the language specified by Language was
>> +                                returned in DriverName.
>> +
>> +  @retval EFI_INVALID_PARAMETER Language is NULL.
>> +
>> +  @retval EFI_INVALID_PARAMETER DriverName is NULL.
>> +
>> +  @retval EFI_UNSUPPORTED       The driver specified by This does not support
>> +                                the language specified by Language.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +EFIAPI
>> +ChaosKeyDriverName (
>> +  IN  EFI_COMPONENT_NAME_PROTOCOL  *This,
>> +  IN  CHAR8                        *Language,
>> +  OUT CHAR16                       **DriverName
>> +  )
>> +{
>> +  return LookupUnicodeString2 (
>> +           Language,
>> +           This->SupportedLanguages,
>> +           mChaosKeyDriverNameTable,
>> +           DriverName,
>> +           (BOOLEAN)(This == &gChaosKeyDriverComponentName)
>> +           );
>> +}
>> +
>> +/**
>> +  Retrieves a Unicode string that is the user readable name of the controller
>> +  that is being managed by a driver.
>> +
>> +  This function retrieves the user readable name of the controller specified by
>> +  ControllerHandle and ChildHandle in the form of a Unicode string. If the
>> +  driver specified by This has a user readable name in the language specified by
>> +  Language, then a pointer to the controller name is returned in ControllerName,
>> +  and EFI_SUCCESS is returned.  If the driver specified by This is not currently
>> +  managing the controller specified by ControllerHandle and ChildHandle,
>> +  then EFI_UNSUPPORTED is returned.  If the driver specified by This does not
>> +  support the language specified by Language, then EFI_UNSUPPORTED is returned.
>> +
>> +  @param  This[in]              A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or
>> +                                EFI_COMPONENT_NAME_PROTOCOL instance.
>> +
>> +  @param  ControllerHandle[in]  The handle of a controller that the driver
>> +                                specified by This is managing.  This handle
>> +                                specifies the controller whose name is to be
>> +                                returned.
>> +
>> +  @param  ChildHandle[in]       The handle of the child controller to retrieve
>> +                                the name of.  This is an optional parameter that
>> +                                may be NULL.  It will be NULL for device
>> +                                drivers.  It will also be NULL for a bus drivers
>> +                                that wish to retrieve the name of the bus
>> +                                controller.  It will not be NULL for a bus
>> +                                driver that wishes to retrieve the name of a
>> +                                child controller.
>> +
>> +  @param  Language[in]          A pointer to a Null-terminated ASCII string
>> +                                array indicating the language.  This is the
>> +                                language of the driver name that the caller is
>> +                                requesting, and it must match one of the
>> +                                languages specified in SupportedLanguages. The
>> +                                number of languages supported by a driver is up
>> +                                to the driver writer. Language is specified in
>> +                                RFC 4646 or ISO 639-2 language code format.
>> +
>> +  @param  ControllerName[out]   A pointer to the Unicode string to return.
>> +                                This Unicode string is the name of the
>> +                                controller specified by ControllerHandle and
>> +                                ChildHandle in the language specified by
>> +                                Language from the point of view of the driver
>> +                                specified by This.
>> +
>> +  @retval EFI_SUCCESS           The Unicode string for the user readable name in
>> +                                the language specified by Language for the
>> +                                driver specified by This was returned in
>> +                                DriverName.
>> +
>> +  @retval EFI_INVALID_PARAMETER ControllerHandle is NULL.
>> +
>> +  @retval EFI_INVALID_PARAMETER ChildHandle is not NULL and it is not a valid
>> +                                EFI_HANDLE.
>> +
>> +  @retval EFI_INVALID_PARAMETER Language is NULL.
>> +
>> +  @retval EFI_INVALID_PARAMETER ControllerName is NULL.
>> +
>> +  @retval EFI_UNSUPPORTED       The driver specified by This is not currently
>> +                                managing the controller specified by
>> +                                ControllerHandle and ChildHandle.
>> +
>> +  @retval EFI_UNSUPPORTED       The driver specified by This does not support
>> +                                the language specified by Language.
>> +
>> +**/
>> +STATIC
>> +EFI_STATUS
>> +EFIAPI
>> +ChaosKeyGetControllerName (
>> +  IN  EFI_COMPONENT_NAME_PROTOCOL                     *This,
>> +  IN  EFI_HANDLE                                      ControllerHandle,
>> +  IN  EFI_HANDLE                                      ChildHandle        OPTIONAL,
>> +  IN  CHAR8                                           *Language,
>> +  OUT CHAR16                                          **ControllerName
>> +  )
>> +{
>> +  if (ChildHandle != NULL) {
>> +    return EFI_UNSUPPORTED;
>> +  }
>> +
>> +  return LookupUnicodeString2 (
>> +           Language,
>> +           This->SupportedLanguages,
>> +           mChaosKeyControllerNameTable,
>> +           ControllerName,
>> +           (BOOLEAN)(This == &gChaosKeyDriverComponentName)
>> +           );
>> +}
>> +
>> +//
>> +// EFI Component Name Protocol
>> +//
>> +EFI_COMPONENT_NAME_PROTOCOL gChaosKeyDriverComponentName = {
>> +  ChaosKeyDriverName,
>> +  ChaosKeyControllerName,
>> +  "eng"
>> +};
>> +
>> +//
>> +// EFI Component Name 2 Protocol
>> +//
>> +EFI_COMPONENT_NAME2_PROTOCOL gChaosKeyDriverComponentName2 = {
>> +  (EFI_COMPONENT_NAME2_GET_DRIVER_NAME) ChaosKeyGetDriverName,
>> +  (EFI_COMPONENT_NAME2_GET_CONTROLLER_NAME) ChaosKeyGetControllerName,
>> +  "en"
>> +};
>> diff --git a/Silicon/Openmoko/ChaosKeyDxe/DriverBinding.c b/Silicon/Openmoko/ChaosKeyDxe/DriverBinding.c
>> new file mode 100644
>> index 000000000000..a1a5a796d38d
>> --- /dev/null
>> +++ b/Silicon/Openmoko/ChaosKeyDxe/DriverBinding.c
>> @@ -0,0 +1,256 @@
>> +/** @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,
>> +        "ChaosKey (0x%04x:0x%04x) is my homeboy!\n",
>> +        Device.IdVendor, Device.IdProduct));
>
> That was intended as a cute remark in my original blog post. Perhaps a
> more descriptive message would be better.
> "Detected ChaosKey RNG device." or such.
>

OK, will change that.

>> +      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,
>> +             &gChaosKeyDriverComponentName, &gChaosKeyDriverComponentName2);
>
> Random question ... do we _want_ to provide
> EFI_COMPONENT_NAME_PROTOCOL, in addition to
> EFI_COMPONENT_NAME2_PROTOCOL, for new drivers?
>

If this is supposed to be a UEFI Driver Model driver, I'd suggest we
keep it for compatibility with older firmwares.

> I should also point out that I don't actually see a DRIVER NAME when
> executing the "drivers" command from UEFI Shell.
>

That worked fine for me, both for 'drivers' and 'devices'. Which
platform? Does it display other driver names correctly?