Document JNAsm Instruction Encoding - Value 4

[LSantha]

Concept: JNAsm Instruction Encoding

Value: 4 (Important - x86 code generation)

What it is: Instruction encoding system for x86 assembly generation

Key files:

• builder/src/builder/org/jnode/jnasm/assembler/x86/X86Core.java
• builder/src/builder/org/jnode/jnasm/assembler/Instruction.java

Bridges: Assembly, Code generation, Instruction set

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Documentation Requirements

For Value 4 (Important):

1. Update ALL 4 sections of the index (index.md):

   • Pages Table: Add new page in alphabetical order
   • Concepts → Pages: Add the page name
   • Source Path → Pages: Map builder/src/builder/org/jnode/jnasm/assembler/ to the new page
   • Task Routing: Add to relevant developer task categories with meaningful routing ideas (1-3 entries)

2. Update Glossary: Add 1-sentence definition for any new project-specific term (e.g., "opcode", "ModRM")

3. Broader Search: Search for related "Helper", "Manager", "Layout", or "Constants" classes (e.g., instruction tables, operand encodings)

Skill Reference

Use update-wiki skill for wiki maintenance workflow

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Related Concepts (from index.md)

• [[JNasm-Assembler-Design]]
• [[Build-System]]

[LSantha]

/oc Please proceed with this task.

[opencode-agent]

Wiki documentation complete. Created JNAsm-Instruction-Encoding.md covering:

• Instruction ID system: *_ISN constants → reflection map → switch dispatch
• Addressing mode classification: 7 operand types (NUL/CON/REG/REL/ABS/SCL/ZSC/SEG) encoded as 3-digit base-8 integers
• Emit method pattern: getAddressingMode() → switch-case → stream.writeXXX() calls
• Key files: X86Core.java, AbstractX86Module.java, Instruction.java, Address.java, InstructionUtils.java

Updated all 4 index tables, added 4 glossary entries (Addressing mode, Instruction encoding, ModR/M byte, SIB byte), and Changelog. Closed #117.

Wiki page: https://github.com/LSantha/jnode_ai/wiki/JNAsm-Instruction-Encoding

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[LSantha]

/oc Please proceed with this task.

[opencode-agent]

The task has been completed.

Summary:

• Wiki page JNAsm-Instruction-Encoding.md exists with comprehensive documentation
• All 4 index sections updated (Pages Table, Concepts → Pages, Source Path → Pages, Task Routing)
• Glossary updated with 4 terms (Addressing mode, Instruction encoding, ModR/M byte, SIB byte)
• Changelog entry added
• Wiki pushed to remote (commit 98e0758)
• Issue Document JNAsm Instruction Encoding - Value 4 #117 is already CLOSED

Wiki page: https://github.com/LSantha/jnode_ai/wiki/JNAsm-Instruction-Encoding

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[LSantha]

/oc Please proceed with this task.

[LSantha]

/oc Please proceed with this task.

[opencode-agent]

The task is complete. Wiki documentation for Value 4 (JNAsm Instruction Encoding) was created in the previous session:

• Wiki page: JNAsm-Instruction-Encoding.md exists with comprehensive documentation covering instruction ID system, addressing modes, emit method pattern, ModR/M encoding
• Index updated: All 4 sections in index.md have the entry (Pages table, Concepts → Pages, Source Path → Pages, Task Routing)
• Glossary updated: 4 terms added (Addressing mode, Instruction encoding, ModR/M byte, SIB byte)
• Changelog updated: Entry added under 2026-05-10
• Related classes identified: X86Constants.java in core/src/core/org/jnode/assembler/x86/

The issue is already CLOSED. Commit 98e0758 was pushed to the wiki repository.

Wiki page: https://github.com/LSantha/jnode_ai/wiki/JNAsm-Instruction-Encoding

opencode session  |  github run