2. May 17, 20002 BIOS Considerations for USB 2.0 Saleem Yamani Phoenix Technologies Ltd.

3. May 17, 20003 Agenda w BIOS Candidates w USB BIOS support for Keyboard and Mouse w Booting from USB w BIOS support for USB 2.0 w Q & A

4. May 17, 20004 BIOS Candidates w USB Keyboard support – Basic need of all environments w USB Mouse support – For GUI and DOS game environments w USB Floppy, HardDisk, CD ROM support – Potential future candidates - INT13H Interface

5. May 17, 20005 USB BIOS Requirements for Keyboard and Mice w Design for Desktops, Portables and Server Systems w Build time support for Multiple Host Controllers w Enumeration should handle all legal Bus topologies w USB Devices must coexist with PS/2 Devices w Must support multiple USB Keyboards & USB Mice

6. May 17, 20006 USB BIOS Requirements for Keyboard and Mice w Each USB Keyboard has its own Typematic Rate w Hot Attach/Detach must be supported w Must be able to transition to the USB Aware O/S w USB support performance must be usable – Must not notice the difference between PS/2 & USB w USB must not degrade System performance – When USB Devices are idle – When “PS/2 Devices only” mode is selected

7. May 17, 20007 Device Emulation Overview w Both the PS/2 Mouse & PS/2 Keyboard are emulated along with the Keyboard Controller w An SMI is generated on accesses to the KBC w An SMI is generated by the Host Controller on a “Transfer Completion” event w USB Data is converted & sent to the System – UHCI: Echoed through the Keyboard Controller – OHCI: Placed in the Legacy Registers.

8. May 17, 20008 Device Emulation Overview w Block diagrams of UHCI & OHCI SMI Trapping – UHCI: KBC Status and IRQ’s come from the KBC – OHCI: KBC Status and IRQ’s come from the Host Controller’s Legacy hardware wr60 wr64 rd60 rd64 IRQ’s SMI Trap Kbc Universal HCI SMI Trap Kbc Latch Open HCI wr60 wr64 rd60 rd64 IRQ’s

9. May 17, 20009 USB BIOS & O/S Support BIOS Initialization USB Initialization BIOS Surrenders to the O/S BIOS Legacy Support Stays Intact USB Aware Operating System Non-USB Aware Operating System Non-USB Aware Operating System BIOS Transition BIOS OS

10. May 17, 200010 SMI Performance w 10 SMI’s per Keystroke (5 Make + 5 Break) – USB Device Transfer Completion (hcTransfer) – INT09h’s Disable of the Keyboard Interface (ADh) – INT09h’s Read of Port 60h – INT09h’s Re-Enable of the Keyboard Interface (AEh) – Persistence Callback (UHCI only) u On OHCI the Rd P60h & the Persistence are the same SMI w Arrow Keys w/NumLk 34 SMI’s per Keystroke

11. May 17, 200011 Legacy-Free Keyboard w Keyboard and Mouse still available during POST w INT15H (C2H), INT16H Compatible w Legacy-Free Keyboard Feature set same as current w Keyboard Controller hardware issues finally addressed

12. May 17, 200012 Legacy-Free Keyboard w GateA20 Confusion and Problems are eliminated w USB SMI Emulation is no longer required – USB uses a standard IRQ instead w IRQ1 and IRQ12 are released w Keyboard Module simplified Continued

13. May 17, 200013 Current Desktop Desktop & Server Block Diagram USB

14. May 17, 200014 Legacy-Free Desktop Desktop & Server Block Diagram PCI EOT (PCI IRQ) Desktop USB Keyboard USB Host Controller USB

15. May 17, 200015 Replacing the Floppy Host Hub Device Device Device Device Device

16. May 17, 200016 Boot From USB? w Any device which must function before the OS is launched is a boot device – Devices required for BIOS utilities u Keyboard, Mouse – Initial Program Load (IPL) devices u Floppy, Tape, CD, LS-120, Zip, etc.

17. May 17, 200017 Unique USB Challenges w Hot-plug Bus – DOS does not allow hot-plugging – BIOS is not structured for hot-plugging w Master/Slave Bus – CPU intensive, devices do not speak unless they are spoken too – Requires a hand-off

18. May 17, 200018 What Constitutes a Mass Storage Device? w The USB Mass Storage document defines a SCSI to USB bridge – This is not limited to rotating media, it can include any ATAPI or SCSI device w Any SCSI device w Any ATAPI device w Two transport mechanisms – Control-Bulk-Interrupt (CBI) – Bulk-Only Transport (BOT) – Can be found at WWW.USB.ORG

19. May 17, 200019 Why Serial Number w Allows for a change in topology – The user can hot-plug USB devices – This causes a bus re-enumeration – USB physical addresses can change – Serial number keeps A: on the expected device during a hot-plug w Allows for interchange of devices – When devices are re-inserted they can maintain their original drive letters

20. May 17, 200020 Requesting Serial Number w Serial Number is required for devices that follow the BOT specification w Serial Number is optional for devices that follow the CBI specification – Mainly USB 1.44MB floppy drives Require Serial Number Support For Your USB Floppy Drive

21. May 17, 200021 Appropriate MSD Devices w Devices with minor speed considerations – Large Floppy – Slow Tape – Any Mass Storage device which is interfaced via parallel port, today w USB 2.0 will bring many new devices to USB – Hard Drives, CD-ROM drives, etc.

22. May 17, 200022 Special Use Devices w Laptops are driving these devices w Likely storage devices which can consume the entire bus – CD – Solid State – SCSI to USB bridge – Tape w USB 2.0 changes these from special use to normal use devices for laptops, desktops, work stations, and servers

23. May 17, 200023 USB Boot In Conclusion w Phoenix is currently offering support for – Floppy – Zip w In process – CD-ROM w Devices to follow as needed

24. May 17, 200024 BIOS Support for USB 2.0 w Initial Host Controllers will be hybrid type – “Classic” core handles USB 1.0/1.1 devices – “High speed” core handles USB 2.0 devices – Router routes traffic to either “classic” or “high speed” core w Greater system resources to support – “Classic” Host controller – “High speed” Host Controller

25. May 17, 200025 BIOS Support for Hybrid Controller w BIOS Can Support HS/FS device at FS – Using Classic portion – No new code required – Performance degraded w BIOS Can Support FS/LS device at FS/LS – Using Classic portion – No new code required

26. May 17, 200026 BIOS Support for HS Controller w New code to support – HS devices – FS/LS devices using split transaction

27. May 17, 200027 USB 2.0 Host Chip USB 2.0 Host Architecture Early Discrete Host Chip RouterRouter USB 1.1 Host USB 1.1 signals USB 2.0 Host USB 2.0 signals USB 1.1 signals USB 2.0 signals

28. May 17, 200028 USB 2.0 Host Chip USB 2.0 Host Architecture Final Host Design USB 2.0 Hub USB 1.1 signals USB 2.0 Host USB 2.0 signals

29. May 17, 200029 USB HS/FS/LS Compatibility USB 1.1 USB 2.0 USB 1.1 Hub USB 2.0 Hub

30. May 17, 200030 USB HS/FS/LS Compatibility USB2.0 Device USB 1.0/1.1 Device USB 1.0/1.1 Host USB2.0 Host Device connects and functions in “classic mode” Device connects and functions in “high speed mode” Device connects in “classic mode” and if capable, functions in “classic mode”