因為在 EFI Driver Model 這篇文章中有提到了一些概念
但是基於自己還有些模糊的情況下
就找了些Sample Code來強化自己的觀念
使用上會有四個Step
但是基於自己還有些模糊的情況下
就找了些Sample Code來強化自己的觀念
使用上會有四個Step
- Initialize：安裝Driver Binding Protocol
- Support()：詢問可不可以支援傳入的Handle
- Start()：連結Device 及 Handle
- Stop()：斷開Device 及 Handle
在設計上要注意到以下幾點
- 符合EFU Model的規範
- 保持Support函式的輕巧，複雜的I/O工作在Start()的時後再做
EDK的Sample 中有個VgaMainPort.c
Initialize：安裝Driver Binding Protocol
EFI_DRIVER_BINDING_PROTOCOL gPciVgaMiniPortDriverBinding = {
PciVgaMiniPortDriverBindingSupported,
PciVgaMiniPortDriverBindingStart,
PciVgaMiniPortDriverBindingStop,
0x00000000,
NULL,
NULL
};
/**
Entrypoint of VGA Mini Port Driver.
This function is the entrypoint of UVGA Mini Port Driver. It installs Driver Binding
Protocols together with Component Name Protocols.
@param ImageHandle The firmware allocated handle for the EFI image.
@param SystemTable A pointer to the EFI System Table.
@retval EFI_SUCCESS The entry point is executed successfully.
**/
FI_STATUS EFIAPI
PciVgaMiniPortDriverEntryPoint (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
Status = EfiLibInstallDriverBindingComponentName2 (
ImageHandle,
SystemTable,
&gPciVgaMiniPortDriverBinding,
ImageHandle,
&gPciVgaMiniPortComponentName,
&gPciVgaMiniPortComponentName2
);
ASSERT_EFI_ERROR (Status);
return EFI_SUCCESS;
}
Support()：詢問可不可以支援傳入的Handle
/**
Check whether VGA Mini Port driver supports this device.
@param This The driver binding protocol.
@param Controller The controller handle to check.
@param RemainingDevicePath The remaining device path.
@retval EFI_SUCCESS The driver supports this controller.
@retval EFI_UNSUPPORTED This device isn't supported.
**/
EFI_STATUS
EFIAPI
PciVgaMiniPortDriverBindingSupported (
IN EFI_DRIVER_BINDING_PROTOCOL *This,
IN EFI_HANDLE Controller,
IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
)
{
EFI_STATUS Status;
EFI_PCI_IO_PROTOCOL *PciIo;
PCI_TYPE00 Pci;
//
// Open the IO Abstraction(s) needed to perform the supported test
//
Status = gBS->OpenProtocol (
Controller,
&gEfiPciIoProtocolGuid,
(VOID **) &PciIo,
This->DriverBindingHandle,
Controller,
EFI_OPEN_PROTOCOL_BY_DRIVER
);
if (EFI_ERROR (Status)) {
return Status;
}
//
// See if this is a PCI VGA Controller by looking at the Command register and
// Class Code Register
//
Status = PciIo->Pci.Read (
PciIo,
EfiPciIoWidthUint32,
0,
sizeof (Pci) / sizeof (UINT32),
&Pci
);
if (EFI_ERROR (Status)) {
goto Done;
}
Status = EFI_UNSUPPORTED;
//
// See if the device is an enabled VGA device.
// Most systems can only have on VGA device on at a time.
//
if (((Pci.Hdr.Command & 0x03) == 0x03) && IS_PCI_VGA (&Pci)) {
Status = EFI_SUCCESS;
}
Done:
gBS->CloseProtocol (
Controller,
&gEfiPciIoProtocolGuid,
This->DriverBindingHandle,
Controller
);
return Status;
}
Start()：連結Device 及 Handle
/**
Starts the VGA device with this driver.
This function consumes PCI I/O Protocol, and installs VGA Mini Port Protocol
onto the VGA device handle.
@param This The driver binding instance.
@param Controller The controller to check.
@param RemainingDevicePath The remaining device patch.
@retval EFI_SUCCESS The controller is controlled by the driver.
@retval EFI_ALREADY_STARTED The controller is already controlled by the driver.
@retval EFI_OUT_OF_RESOURCES Failed to allocate resources.
**/
EFI_STATUS
EFIAPI
PciVgaMiniPortDriverBindingStart (
IN EFI_DRIVER_BINDING_PROTOCOL *This,
IN EFI_HANDLE Controller,
IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
)
{
EFI_STATUS Status;
EFI_PCI_IO_PROTOCOL *PciIo;
PCI_VGA_MINI_PORT_DEV *PciVgaMiniPortPrivate;
PciVgaMiniPortPrivate = NULL;
PciIo = NULL;
//
// Open the IO Abstraction(s) needed
//
Status = gBS->OpenProtocol (
Controller,
&gEfiPciIoProtocolGuid,
(VOID **) &PciIo,
This->DriverBindingHandle,
Controller,
EFI_OPEN_PROTOCOL_BY_DRIVER
);
if (EFI_ERROR (Status)) {
goto Done;
}
//
// Allocate the private device structure
//
PciVgaMiniPortPrivate = AllocateZeroPool (sizeof (PCI_VGA_MINI_PORT_DEV));
ASSERT (PciVgaMiniPortPrivate != NULL);
//
// Initialize the private device structure
//
PciVgaMiniPortPrivate->Signature = PCI_VGA_MINI_PORT_DEV_SIGNATURE;
PciVgaMiniPortPrivate->Handle = Controller;
PciVgaMiniPortPrivate->PciIo = PciIo;
PciVgaMiniPortPrivate->VgaMiniPort.SetMode = PciVgaMiniPortSetMode;
PciVgaMiniPortPrivate->VgaMiniPort.VgaMemoryOffset = 0xb8000;
PciVgaMiniPortPrivate->VgaMiniPort.CrtcAddressRegisterOffset = 0x3d4;
PciVgaMiniPortPrivate->VgaMiniPort.CrtcDataRegisterOffset = 0x3d5;
PciVgaMiniPortPrivate->VgaMiniPort.VgaMemoryBar = EFI_PCI_IO_PASS_THROUGH_BAR;
PciVgaMiniPortPrivate->VgaMiniPort.CrtcAddressRegisterBar = EFI_PCI_IO_PASS_THROUGH_BAR;
PciVgaMiniPortPrivate->VgaMiniPort.CrtcDataRegisterBar = EFI_PCI_IO_PASS_THROUGH_BAR;
PciVgaMiniPortPrivate->VgaMiniPort.MaxMode = 1;
//
// Install VGA Mini Port Protocol
//
Status = gBS->InstallMultipleProtocolInterfaces (
&Controller,
&gEfiVgaMiniPortProtocolGuid,
&PciVgaMiniPortPrivate->VgaMiniPort,
NULL
);
Done:
if (EFI_ERROR (Status)) {
gBS->CloseProtocol (
Controller,
&gEfiPciIoProtocolGuid,
This->DriverBindingHandle,
Controller
);
if (PciVgaMiniPortPrivate != NULL) {
FreePool (PciVgaMiniPortPrivate);
}
}
return Status;
}
Stop()：斷開Device 及 Handle
/**
Stop the VGA device with this driver.
This function uninstalls VGA Mini Port Protocol from the VGA device handle,
and closes PCI I/O Protocol.
@param This The driver binding protocol.
@param Controller The controller to release.
@param NumberOfChildren The child number that opened controller
BY_CHILD.
@param ChildHandleBuffer The array of child handle.
@retval EFI_SUCCESS The controller or children are stopped.
@retval EFI_DEVICE_ERROR Failed to stop the driver.
**/
EFI_STATUS
EFIAPI
PciVgaMiniPortDriverBindingStop (
IN EFI_DRIVER_BINDING_PROTOCOL *This,
IN EFI_HANDLE Controller,
IN UINTN NumberOfChildren,
IN EFI_HANDLE *ChildHandleBuffer
)
{
EFI_STATUS Status;
EFI_VGA_MINI_PORT_PROTOCOL *VgaMiniPort;
PCI_VGA_MINI_PORT_DEV *PciVgaMiniPortPrivate;
Status = gBS->OpenProtocol (
Controller,
&gEfiVgaMiniPortProtocolGuid,
(VOID **) &VgaMiniPort,
This->DriverBindingHandle,
Controller,
EFI_OPEN_PROTOCOL_GET_PROTOCOL
);
if (EFI_ERROR (Status)) {
return Status;
}
PciVgaMiniPortPrivate = PCI_VGA_MINI_PORT_DEV_FROM_THIS (VgaMiniPort);
Status = gBS->UninstallProtocolInterface (
Controller,
&gEfiVgaMiniPortProtocolGuid,
&PciVgaMiniPortPrivate->VgaMiniPort
);
if (EFI_ERROR (Status)) {
return Status;
}
gBS->CloseProtocol (
Controller,
&gEfiPciIoProtocolGuid,
This->DriverBindingHandle,
Controller
);
FreePool (PciVgaMiniPortPrivate);
return EFI_SUCCESS;
}
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