EDK II UEFI Driver Writer's Guide
EDK II UEFI Driver Writer's Guide
EDK II UEFI Driver Writer's Guide
EDK II UEFI Driver Writer's Guide
Introduction
Tables
Figures
Examples
Acknowledgements
1 Introduction
2 UEFI Driver Implementation Checklist
3 Foundation
4 General Driver Design Guidelines
5 UEFI Services
6 UEFI Driver Categories
7 Driver Entry Point
8 Private Context Data Structures
9 Driver Binding Protocol
10 UEFI Service Binding Protocol
11 UEFI Driver and Controller Names
12 UEFI Driver Configuration
13 UEFI Driver Diagnostics
14 Driver Health Protocol
15 Driver Family Override Protocol
16 Driver Supported EFI Version Protocol
17 Bus-Specific Driver Override Protocol
18 PCI Driver Design Guidelines
19 USB Driver Design Guidelines
20 SCSI Driver Design Guidelines
21 ATA Driver Design Guidelines
22 Text Console Driver Design Guidelines
23 Graphics Driver Design Guidelines
24 Mass Storage Driver Design Guidelines
25 Network Driver Design Guidelines
26 User Credential Driver Design Guidelines
27 Load File Driver Design Guidelines
28 IPF Platform Porting Considerations
29 EFI Byte Code Porting Considerations
29.1 No Assembly Support
29.2 No C++ Support
29.3 No Floating Point Support
29.4 Use of sizeof()
29.5 Natural Integers and Fixed Size Integers
29.6 Memory ordering
29.7 Performance considerations
29.8 UEFI Driver Entry Point
30 Building UEFI Drivers
31 Testing and Debugging UEFI Drivers
32 Distributing UEFI Drivers
Appendix A EDK II File Templates
Appendix B EDK II Sample Drivers
Appendix C Glossary
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29 EFI Byte Code Porting Considerations

There are a few considerations to keep in mind when writing drivers that may be ported to EBC (EFI byte code). This chapter describes these considerations in detail and, where applicable, provides solutions to address them. If UEFI drivers are implemented with these considerations in mind, the C code may not require any changes. In this case, a native driver may be ported to EBC simply by recompiling the driver sources using the Intel(R) C Compiler for EFI Byte Code. The tasks required to convert a UEFI Driver to an EBC include the following:

  • Port assembly language sources to C language sources.

  • Port C++ language sources to C language sources.

  • Eliminate use of the float type.

  • Convert floating point math operations to integer math operations.

  • Eliminate use of sizeof() in statements that require a constant.

  • Avoid arithmetic operations and comparisons between natural integers and fixed size integers. Some specific combinations produce unexpected results.

  • Optimize for performance

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28.7 Speculation and floating point register usage
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29.1 No Assembly Support
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