2. ATA Miniport Nuts and Bolts
Michael Xing
SDE II
Device and Storage Technologies

3. Agenda Why ATA Miniport? ATA Port / Miniport Model
ATA Port / Miniport Interfaces
New Interfaces in Windows 7
Best Practices

4. Why ATA miniport? Do I need an miniport driver?
Controllers supported by inbox drivers
Microsoft inbox ATA miniport drivers:
atapi.sys – developed for legacy PATA controllers
msahci.sys – developed for SATA controllers
Consider options other than a driver
Special requirements that are not covered by inbox drivers:
Your hardware uses ATA protocol but has a different transfer layer or exposes special feature(s)
Contact us about feature support before developing your own miniport driver

5. Why ATA miniport? Which port driver model should I use?
Windows versions support
ATAport: Vista and later
Storport: Server 2003 and later
Command protocol selection
ATAport / miniport command protocol: ATA
Storport / miniport command protocol: SCSI
Common ATA functionalities implemented in ATA port driver
Such as set device attributes, set transfer mode, etc.
Less code in miniport

6. ATA Port/Miniport Model – Driver Stack
Class Driver
ATA Port DLLs - ATAport.sys - PCIIDEx.sys
ATA Miniport Driver
PCI Driver

7. ATA Port/Miniport Model – Loading Sequence
PCIIDEx.sys
Create
Channel FDO
Create
Device FDO
Load ATA Miniport
Load
ATAport.sys
Create
Channel PDO
Load
Class Driver
Create
Controller PDO
Enumerate
Channels
Create
Device PDO
PCI Driver
Create
Controller FDO
Enumerate
Devices
ATA Controller

8. ATA Port/Miniport Model – Role of ATA Port Driver
I/O translation into ATA protocol
I/O queuing with prioritization considered
Sense Data generation for ATA devices
PnP and power request handling
Request to miniport driver in push mode

9. ATA Port/Miniport Model – Role of ATA Miniport Driver
Convert ATA command into final transfer layer package if necessary
Send final command to device
Monitor interrupt for command completion
Negotiate for channel and device parameters
Select queue depth
Freeze/unfreeze queue according to device status

10. Port / Miniport Interfaces – General
ATAport
Default Miniport
ATA Port DLLs - ATAport.sys - PCIidex.sys
Channel Interface
ATA Controller
I/O
Controller Interface
Vendor Miniport
ATA Miniport Driver
PCIidex

11. Port / Miniport Interfaces – Miniport Major Routines
Controller Interface Routines
DriverEntry()
AtaAdapterControl() – PnP, power operations
AtaControllerChannelEnabled() – Channel is usable or not
Channel Interface Routines
AtaChannelInitRoutine() – Set routine pointers for channel
IdeHwControl() – PnP, power operations
IdeHwInitialize() – Device initialization
IdeHwBuildIo() – I/O preparation
IdeHwStartIo() – Execute the I/O
IdeHwInterrupt() – Monitor hardware activities; process I/O completion

12. Port / Miniport Interfaces - Controller Interfaces
ATA Port Processes
AtaControllerChannelEnabled()
Create
Channel PDO
AtaAdapterControl() with IdeStart
Enumerate
Channels
DriverEntry()
(Set callback function pointers)
Start Device (Controller)
Add Device -
Create Controller FDO
Load
PCIIDEx.sys
Load ATA Miniport
Load
ATAport.sys
AtaPortInitializeEx()

13. Port / Miniport Interfaces - Channel Interfaces
ATA Port Processes
IdeHwInterrupt()
I/O
IdeHwStartIo()
Create
Device PDO
IdeHwBuildIo()
Configure Devices
IdeHwInitialize()
Enumerate
Devices
IdeHwControl()
with IdeStart
Start Channel
AtaChannelInitRoutine()
Add Device –
Create Channel FDO

14. Port / Miniport Interfaces – I/O Interface
IDE_REQUEST_BLOCK
Contains
Structure for ATA TaskFile
I/O execute mode – PIO or DMA
Data buffer for the I/O
Other information needed by Miniport driver to execute the command
Status and Error field
Usage
I/O request
Miniport action, such as power down the device
// 0x x1FF indicate ATA commands
#define IRB_FUNCTION_ATA_COMMAND x100
#define IRB_FUNCTION_ATA_IDENTIFY x101
#define IRB_FUNCTION_ATA_READ x102
#define IRB_FUNCTION_ATA_WRITE x103
#define IRB_FUNCTION_ATA_FLUSH x104
#define IRB_FUNCTION_ATA_SMART x105
// 0x x2FF indicate ATAPI commands
#define IRB_FUNCTION_ATAPI_COMMAND x200
#define IRB_FUNCTION_REQUEST_SENSE x201
// 0x400-0x4FF indicate miniport commands
#define IRB_FUNCTION_MINIPORT_COMMAND 0x400
#define IRB_FUNCTION_ADAPTER_FLUSH x401
#define IRB_FUNCTION_SHUTDOWN x402
#define IRB_FUNCTION_POWER_CHANGE x403
#define IRB_FUNCTION_LUN_RESET x404
#define IRB_FUNCTION_MINIPORT_IOCTL 0x405
#define IRB_FUNCTION_POWER_REBOOT x406

15. New Interfaces in Windows 7
System Reboot Notification
IRB_FUNCTION_POWER_REBOOT
Vendor-Defined Power Management
IDE_CONTROL_ACTION – IdeVendorDefined
Device Parameter Flags
Removable Device Flag – DFLAGS_REMOVABLE_DEVICE
FUA Support Flag – DFLAGS_FUA_SUPPORT

16. Best Practices - Device Parameter Changes
Changing removable device flag in Microsoft Miniport driver for SATA controller
BOOLEAN
AhciHwInitialize (
IN PVOID ChannelExtension,
IN OUT PIDE_DEVICE_PARAMETERS DeviceParameters,
IN PIDENTIFY_DEVICE_DATA IdentifyData ) { …
// 3.1 Removable Device Detect
if ((channelExtension->Px->CMD.HPCP) ||
((channelExtension->CAP.SXS) && (channelExtension->Px->CMD.ESP))) {
// Px->CMD.HPCP indicates that the port is hot-pluggable. (both signal and power cable)
// CAP.SXS && Px->CMD.ESP indicates that it's an ESATA port. (only signal cable)
DeviceParameters->DeviceCharacteristics |= DFLAGS_REMOVABLE_DEVICE; }
return TRUE;

17. Best Practices – Pause Process
AtaPortStallExecution()
Spin locks the CPU for x microseconds
Less than one millisecond delays
Should be used during hibernate or crash dump
AtaPortRequestTimer()
Causes the port driver to trigger a callback routine after x microseconds
Greater than one millisecond delays
Best when used with multiphase functions

18. Best Practices – I/O Error Reporting
IRB_STATUS_DEVICE_ERROR
Most common I/O error code
IRB_STATUS_BUSY
Host is busy
Make sure to pause the queues with AtaPortDeviceBusy()
IRB_STATUS_SELECTION_TIMEOUT
Not necessarily retried
Port driver may reset the device
IRB AtaStatus and Error fields
Only valid on IRB_STATUS_DEVICE_ERROR or IRB_STATUS_SELECTION_TIMEOUT

19. Calls to Action Read “ATA Miniport Drivers” in MSDN
Refer to sample code
Microsoft Miniport driver for AHCI controller in WDK at src\storage\msahci
Ask questions at ATA Miniport Driver Development Forum
Contact us about feature support:

20. Resources Related Specifications Related Sessions
ATA -
SATA -
AHCI -
Related Sessions
Session
Day / Time
Storport Drivers from the Ground Up
Tues. 8:30-9:30 and Wed. 9:45-10:45
Storport Smorgasboard
Tues. 4-5 and
Wed

21. Questions ?