BIOS Considerations for USB 2.0

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BIOS Considerationsfor USB 2.0

• Curtis E. Stevens
• Phoenix Technologies Ltd.

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Agenda

• BIOS Candidates
• USB BIOS support for Keyboard and Mouse
• Booting from USB
• BIOS support for USB 2.0

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BIOS Candidates

• USB Keyboard support
• Basic need of all environments
• USB Mouse support
• For GUI and DOS game environments
• USB Floppy, HardDisk, CD ROM support
• Potential future candidates - INT13H Interface

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USB BIOS Requirementsfor Keyboard and Mice

• Design for Desktops, Portables andServer Systems
• Support for Multiple Host Controllers
• Enumeration should handle all legalBus
  topologies
• USB Devices must coexist with PS/2 Devices
• Must support multiple USB Keyboards USB Mice

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USB BIOS Requirementsfor Keyboard and Mice

• Each USB Keyboard has its own Typematic Rate
• Hot Attach/Detach must be supported
• Must be able to transition to the USB Aware O/S
• USB support performance must be usable
• Must not notice the difference between PS/2 USB
• USB must not degrade System performance
• When USB Devices are idle
• When PS/2 Devices only mode is selected

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Device Emulation Overview

• Both the PS/2 Mouse PS/2 Keyboard are emulated
  along with the Keyboard Controller
• An SMI is generated on accesses to the KBC
• An SMI is generated by the Host Controller on a
  Transfer Completion event
• USB Data is converted sent to the System
• UHCI Echoed through the Keyboard Controller
• OHCI Placed in the Legacy Registers.

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Device Emulation Overview

• Block diagrams of UHCI OHCI SMI Trapping
• UHCI KBC Status and IRQs come from the KBC
• OHCI KBC Status and IRQs come from the Host
  Controllers Legacy hardware

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USB BIOS O/S Support
USB Aware Operating System
BIOS Surrenders To the O/S
BIOS Initialization
BIOS Transition
USB Initialization
Non-USB Aware Operating System
BIOS Legacy Support Stays Intact
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PS/2-Only Architecture
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BIOS USB PS/2 Architecture
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BIOS USB PS/2 Architecture
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SMI Performance

• 10 SMIs per Keystoke (5 Make 5 Break)
• USB Device Transfer Completion (hcTransfer)
• INT09hs Disable of the Keyboard Interface (ADh)
• INT09hs Read of Port 60h
• INT09hs Re-Enable of the Keyboard Interface
  (AEh)
• Persistence Callback (UHCI only)
• On OHCI the Rd P60h the Persistence are the
  same SMI
• Arrow Keys w/NumLk 34 SMIs per Keystroke

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Legacy-Free Keyboard

• Keyboard and Mouse still available during POST
• INT15H (C2H), INT16H Compatible
• Legacy-Free Keyboard Feature set same as current
• Keyboard Controller hardware issues finally
  addressed
• GateA20 Confusion and Problems are eliminated
• USB SMI Emulation is no longer required
• USB uses a standard IRQ instead
• New OS hand-off required for IRQ keyboard
  emulation
• IRQ1 and IRQ12 are released
• Keyboard Module simplified

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Current Desktop
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Legacy-Free Desktop
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Replacing the Floppy
Booting From USB
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What Constitutes A Mass Storage Device?

• Any SCSI device
• Any ATAPI device
• Two transport mechanisms
• Control-Bulk-Interrupt (CBI)
• Bulk-Only Transport (BOT)
• Can be found at WWW.USB.ORG

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Why Serial Number

• 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
• Allows for interchange of devices
• When devices are re-inserted they can maintain
  their original drive letters

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Requesting Serial Number

• Serial Number is required for devices that follow
  the BOT specification
• Serial Number is optional for devices that follow
  the CBI specification
• Mainly USB 1.44MB floppy drives

Require Serial Number Supportfor Your USB Floppy
Drive
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Mode Page 5(Flexible Disk Page)

• Required by system firmware
• Useful for devices that use preformatted media
• Provides Cylinder-Head-Sector information
  forBIOS services
• The system BIOS does not read parameters from
  media
• The system BIOS only reads parameters from
  devices
• Required for devices that would be A
• Guarantees media compatibility from system to
  system
• Required for devices that would be C
• Guarantees that partition table parameters are
  consistent from system to system

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Appropriate Devices

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

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Special Use Devices

• Laptops are driving these devices
• IA Products
• USB 2.0 changes these from special use devices to
  normal use devices for Laptops, Desktops,
  Workstations, Servers

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USB Boot In Conclusion

• Phoenix is currently offering support for
• Floppy
• Zip
• Hard Drive
• CD-ROM/DVD
• In process
• USB 2.0
• Target date H1 2002
• Devices to follow as needed

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Support USB 2.0 Host
USB 1.1 Signals
USB 2.0 Signals
USB 2.0Host Chip
Router
USB 1.1Host
USB 2.0Host
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BIOS Support forHybrid Controller

• BIOS Can Support HS/FS device at FS
• Using Classic portion
• No new code required
• Performance degraded
• BIOS Can Support FS/LS device at FS/LS
• Using Classic portion
• No new code required

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BIOS Support forHS Controller

• New code to support
• HS devices
• FS/LS devices using split transaction

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Summary

• USB keyboard legacy emulation should be shipped
  on all systems with USB and KBC
• USB mass storage is now available as a secondary
  boot device
• Require serial numbers in your massstorage
  devices
• Send us some prototype USB 2.0 massstorage
  devices

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For More Information

• WWW.USB.ORG
• WWW.PHOENIX.COM
• For questions related to Phoenix BIOSes
• E-Mail Robert_Mendez_at_Phoenix.com regarding
  Phoenix BIOS
• E-Mail Kangkang_Shen_at_Phoenix.com regarding Award
  BIOS
• E-Mail Curtis_Stevens_at_Phoenix.com regarding
  general questions specification issues

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Any Questions?