米6体育平台手机版

SPRU513Y August 2001 – June 2022 SM320F28335-EP

Read This First
1. About This Manual
2. How to Use This Manual
3. Notational Conventions
4. Related Documentation From Texas Instruments
5. Trademarks
1 Introduction to the Software Development Tools
1. 1.1 Software Development Tools Overview
2. 1.2 Tools Descriptions
2 Introduction to Object Modules
1. 2.1 Object File Format Specifications
2. 2.2 Executable Object Files
3. 2.3 Introduction to Sections
  1. 2.3.1 Special Section Names
4. 2.4 How the Assembler Handles Sections
5. 2.5 How the Linker Handles Sections
  1. 2.5.1 Combining Input Sections
  2. 2.5.2 Placing Sections
6. 2.6 Symbols
7. 2.7 Symbolic Relocations
  1. 2.7.1 Expressions With Multiple Relocatable Symbols (COFF Only)
8. 2.8 Loading a Program
3 Program Loading and Running
1. 3.1 Loading
  1. 3.1.1 Load and Run Addresses
  2. 3.1.2 Bootstrap Loading
2. 3.2 Entry Point
3. 3.3 Run-Time Initialization
4. 3.4 Arguments to main
5. 3.5 Run-Time Relocation
6. 3.6 Additional Information
4 Assembler Description
1. 4.1 Assembler Overview
2. 4.2 The Assembler's Role in the Software Development Flow
3. 4.3 Invoking the Assembler
4. 4.4 Controlling Application Binary Interface
5. 4.5 Naming Alternate Directories for Assembler Input
  1. 4.5.1 Using the --include_path Assembler Option
  2. 4.5.2 Using the C2000_A_DIR Environment Variable
6. 4.6 Source Statement Format
7. 4.7 Literal Constants
8. 4.8 Assembler Symbols
9. 4.9 Expressions
10. 4.10 Built-in Functions and Operators
  1. 4.10.1 Built-In Math and Trigonometric Functions
11. 4.11 TMS320C28x Assembler Extensions
12. 4.12 Source Listings
13. 4.13 Debugging Assembly Source
14. 4.14 Cross-Reference Listings
15. 4.15 Smart Encoding
16. 4.16 Pipeline Conflict Detection
5 Assembler Directives
1. 5.1 Directives Summary
2. 5.2 Directives that Define Sections
3. 5.3 Directives that Initialize Values
4. 5.4 Directives that Perform Alignment and Reserve Space
5. 5.5 Directives that Format the Output Listings
6. 5.6 Directives that Reference Other Files
7. 5.7 Directives that Enable Conditional Assembly
8. 5.8 Directives that Define Union or Structure Types
9. 5.9 Directives that Define Enumerated Types
10. 5.10 Directives that Define Symbols at Assembly Time
11. 5.11 Miscellaneous Directives
12. 5.12 Directives Reference
  1. .align
  2. .asg/.define/.eval
  3. .asmfunc/.endasmfunc
  4. .bits
  5. .bss
  6. .byte/.ubyte/.char/.uchar
  7. .cdecls
  8. .clink
  9. .common
  10. .copy/.include
  11. .cstruct/.cunion/.endstruct/.endunion/.tag
  12. .data
  13. .drlist/.drnolist
  14. .elfsym
  15. .emsg/.mmsg/.wmsg
  16. .end
  17. .fclist/.fcnolist
  18. .field
  19. .float/.xfloat/.xldouble
  20. .global/.def/.ref
  21. .group/.gmember/.endgroup
  22. .if/.elseif/.else/.endif
  23. .int/.unint/.word/.uword
  24. .label
  25. .length/.width
  26. .list/.nolist
  27. .long/.ulong/.xlong
  28. .loop/.endloop/.break
  29. .macro/.endm
  30. .mlib
  31. .mlist/.mnolist
  32. .newblock
  33. .option
  34. .page
  35. .preserve
  36. .retain / .retainrefs
  37. .sblock
  38. .sect
  39. .set
  40. .space/.bes
  41. .sslist/.ssnolist
  42. .string/.cstring/.pstring
  43. .struct/.endstruct/.tag
  44. .symdepend
  45. .tab
  46. .text
  47. .title
  48. .unasg/.undefine
  49. .union/.endunion/.tag
  50. .usect
  51. .var
  52. .weak
6 Macro Language Description
1. 6.1 Using Macros
2. 6.2 Defining Macros
3. 6.3 Macro Parameters/Substitution Symbols
4. 6.4 Macro Libraries
5. 6.5 Using Conditional Assembly in Macros
6. 6.6 Using Labels in Macros
7. 6.7 Producing Messages in Macros
8. 6.8 Using Directives to Format the Output Listing
9. 6.9 Using Recursive and Nested Macros
10. 6.10 Macro Directives Summary
7 Archiver Description
1. 7.1 Archiver Overview
2. 7.2 The Archiver's Role in the Software Development Flow
3. 7.3 Invoking the Archiver
4. 7.4 Archiver Examples
5. 7.5 Library Information Archiver Description
8 Linker Description
1. 8.1 Linker Overview
2. 8.2 The Linker's Role in the Software Development Flow
3. 8.3 Invoking the Linker
4. 8.4 Linker Options
5. 8.5 Linker Command Files
6. 8.6 Linker Symbols
7. 8.7 Default Placement Algorithm
  1. 8.7.1 How the Allocation Algorithm Creates Output Sections
  2. 8.7.2 Reducing Memory Fragmentation
8. 8.8 Using Linker-Generated Copy Tables
9. 8.9 Linker-Generated CRC Tables and CRC Over Memory Ranges
10. 8.10 Partial (Incremental) Linking
11. 8.11 Linking C/C++ Code
12. 8.12 Linker Example
9 Absolute Lister Description
1. 9.1 Producing an Absolute Listing
2. 9.2 Invoking the Absolute Lister
3. 9.3 Absolute Lister Example
10Cross-Reference Lister Description
1. 10.1 Producing a Cross-Reference Listing
2. 10.2 Invoking the Cross-Reference Lister
3. 10.3 Cross-Reference Listing Example
11Object File Utilities
1. 11.1 Invoking the Object File Display Utility
2. 11.2 Invoking the Disassembler
3. 11.3 Invoking the Name Utility
4. 11.4 Invoking the Strip Utility
12Hex Conversion Utility Description
1. 12.1 The Hex Conversion Utility's Role in the Software Development Flow
2. 12.2 Invoking the Hex Conversion Utility
  1. 12.2.1 Invoking the Hex Conversion Utility From the Command Line
  2. 12.2.2 Invoking the Hex Conversion Utility With a Command File
3. 12.3 Understanding Memory Widths
4. 12.4 The ROMS Directive
  1. 12.4.1 When to Use the ROMS Directive
  2. 12.4.2 An Example of the ROMS Directive
5. 12.5 The SECTIONS Directive
6. 12.6 The Load Image Format (--load_image Option)
  1. 12.6.1 Load Image Section Formation
  2. 12.6.2 Load Image Characteristics
7. 12.7 Excluding a Specified Section
8. 12.8 Assigning Output Filenames
9. 12.9 Image Mode and the --fill Option
10. 12.10 Array Output Format
11. 12.11 Building a Table for an On-Chip Boot Loader
12. 12.12 Using Secure Flash Boot on TMS320F2838x Devices
13. 12.13 Controlling the ROM Device Address
14. 12.14 Control Hex Conversion Utility Diagnostics
15. 12.15 Description of the Object Formats
16. 12.16 Hex Conversion Utility Error Messages
13Sharing C/C++ Header Files With Assembly Source
1. 13.1 Overview of the .cdecls Directive
2. 13.2 Notes on C/C++ Conversions
3. 13.3 Notes on C++ Specific Conversions
4. 13.4 Special Assembler Support
A Symbolic Debugging Directives
1. A.1 DWARF Debugging Format
2. A.2 Debug Directive Syntax
B XML Link Information File Description
1. B.1 XML Information File Element Types
2. B.2 Document Elements
  1. B.2.1 Header Elements
  2. B.2.2 Input File List
  3. B.2.3 Object Component List
  4. B.2.4 Logical Group List
  5. B.2.5 Placement Map
  6. B.2.6 Symbol Table
C CRC Reference Implementation
1. C.1 Compilation Instructions
2. C.2 Reference CRC Calculation Routine
  1. C.2.1 Reference Implementation of a CRC Calculation Function: ref_crc.c
3. C.3 Linker-Generated Copy Tables and CRC Tables
  1. C.3.1 Main Routine for Example Application: main.c
  2. C.3.2 Checking CRC Values: check_crc.c
  3. C.3.3 Task1 Routine: task1.c
  4. C.3.4 Task2 Routine: task2.c
  5. C.3.5 Task3 Routine: task3.c
  6. C.3.6 Example 1 Command File: ex1.cmd (for COFF)
D Glossary
1. D.1 Terminology
E Revision History
499
500
501
502
E Earlier Revisions

.retain / .retainrefs

Conditionally Retain Sections In Object Module Output

Syntax

.retain["section name"]

.retainrefs["section name"]

Description

The .retain directive indicates that the current or specified section is not eligible for removal via conditional linking. You can also override conditional linking for a given section with the --retain linker option. You can disable conditional linking entirely with the --unused_section_elimination=off linker option.

The .retainrefs directive indicates that any sections that refer to the current or specified section are not eligible for removal via conditional linking. For example, applications may use an .intvecs section to set up interrupt vectors. The .intvecs section is eligible for removal during conditional linking by default. You can force the .intvecs section and any sections that reference it to be retained by applying the .retain and .retainrefs directives to the .intvecs section.

Note:

The .retain and .retainrefs directives are supported only for EABI. They are ignored when used with the COFF ABI.

The section name identifies the section. If the directive is used without a section name, it applies to the current initialized section. If the directive is applied to an uninitialized section, the section name is required. The section name must be enclosed in double quotes. A section name can contain a subsection name in the form section name:subsection name.

The linker assumes that all sections by default are eligible for removal via conditional linking. (However, the linker does automatically retain the .reset section.) The .retain directive is useful for overriding this default conditional linking behavior for sections that you want to keep included in the link, even if the section is not referenced by any other section in the link. For example, you could apply a .retain directive to an interrupt function that you have written in assembly language, but which is not referenced from any normal entry point in the application.

Under the COFF ABI model, the linker assumes that all sections are not eligible for removal via conditional linking by default. So under the COFF ABI mode, the .retain directive does not have any real effect on the section.