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

[Leif Lindholm <leif.lindholm@linaro.org>]

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.

> 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).

> +
> +    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.

> +
> +#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 @@
> +/** @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.

> +      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?

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

/
    Leif

> +  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;
> +}
> -- 
> 2.11.0
>