tel69589584emailwangbox@163com(編輯修改稿)
2024-11-29 17:04 本頁(yè)面
【文章內(nèi)容簡(jiǎn)介】 Preventing Alignment Faults VOID ScsiDeviceNodeInit ( IN OUT SCSI_DEVICE_PATH *ScsiDeviceNode, IN UINT16 Pun, IN UINT16 Lun ) { ScsiDeviceNode = MESSAGING_DEVICE_PATH。 ScsiDeviceNode = MSG_SCSI_DP。 SetDevicePathNodeLength (amp。ScsiDeviceNode, sizeof(SCSI_DEVICE_PATH))。 ScsiDeviceNode = Pun。 ScsiDeviceNode = Lun。 } BAD ScsiDeviceNode may not be aligned Driver Guidelines Preventing Alignment Faults VOID ScsiDeviceNodeInit ( IN OUT SCSI_DEVICE_PATH *ScsiDeviceNode, IN UINT16 Pun, IN UINT16 Lun ) { SCSI_DEVICE_PATH MyDeviceNode。 = MESSAGING_DEVICE_PATH。 = MSG_SCSI_DP。 SetDevicePathNodeLength (amp。, sizeof(SCSI_DEVICE_PATH))。 = Pun。 = Lun。 gBSCopyMem (ScsiDeviceNode, amp。MyDeviceNode, sizeof(SCSI_DEVICE_PATH))。 } GOOD gBSCopyMem() handles all alignments MyDeviceNode is aligned Driver Guidelines Use EFI Driver Library Functions CHILD_DEVICE Child。 Child = EfiLibAllocateZeroPool (sizeof (CHILD_DEVICE))。 if (Child == NULL) { return EFI_OUT_OF_RESOURCES。 } Library Functions Simplify Source Code Library Functions May Reduce Size CHILD_DEVICE Child。 Status = gBSAllocatePool ( EfiBootServicesData, sizeof (CHILD_DEVICE), amp。Child )。 if (EFI_ERROR (Status)) { return Status。 } gBSSetMem (Child, sizeof (CHILD_DEVICE), 0)。 OK GOOD Driver Guidelines EFI Device Paths ? () ChildDevicePath = EfiAppendDevicePathNode ( ControllerDevicePath, ChildDevicePathNode )。 if (ChildDevicePath == NULL) { return(EFI_OUT_OF_RESOURCES)。 } gBSFreePool (ChildDevicePath)。 ? () Parent Device Path is Opaque Not Parsed by Bus Drivers Driver Guidelines Bus Walk Tips ? Use LocateHandleBuffer(Bus I/O Protocol) ? Do not scan PCI configuration space ? Implement support for RemainingDevicePath ? Highly remended for all bus drivers ? (. SCSI, Fibre Channel, etc.) ? Allows bus driver to bypass full enumeration. ? Reduces boot time Driver Guidelines Component Name Protocol ? Limit Lengths of Names to 40 Unicode Characters ? Include Driver Name and Version Number ? UNDI Driver (Network Interface Controller) ? Typically the Name of the PCI Controller ? MAC Node Produced by an UNDI Driver ? Identify Location of Physical Connector on NIC ? PCI Slots ? Identify Physical Location of PCI Slots in the System ? SCSI / SCSI RAID / Fiber Channel ? Controller Typically name of the PCI Controller ? Channel Identify Physical Location of the SCSI Channel ? Disk Use Results from INQUIRY Command Driver Guidelines Option ROM Size Reduction ? Use EFI Compression ? Compile with EFI Byte Code Compiler ? Single Binary for x86, x64 and Itanium ? Smaller than Itanium Binaries ? Comparable to x86 Binaries ? Compresses Well ~ 50% Driver Guidelines How To Improve Portability ? Do Not Assume Max Number of Children ? Do Not Use Fixed Memory Addresses ? Do Not Use Assembly ? Do Not Use Floating Point Arithmetic ? Some Minor EBC Porting Considerations ? Bus Drivers Should Support Producing 1 Child at a time if possible (improves boot performance) D
教學(xué)課件相關(guān)推薦
鄂ICP備17016276號(hào)-1