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Difference between revisions of "Sx assembler"

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Work is in progress on a [http://boost.org/libs/spirit/doc/introduction.html boost.spirit] based SX assembler.
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I'm toying with the creation of a [http://boost.org/libs/spirit/doc/introduction.html boost.spirit] based SX assembler, written in C++.
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'''update''': I'm reconsidering writing the grammar of the assembler in [http://antlr.org/ ANTLR] instead of spirit, so that i could use the same grammar in Java (eclipse) and C++ (tool chain).
  
 
The sx assembler consists of 2 parts:
 
The sx assembler consists of 2 parts:
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** include
 
** include
 
** macros
 
** macros
** recognizing opcodes that start in the label column (the first column).
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** <strike>recognizing opcodes that start in the label column (the first column). Currently, a word that starts in the first column will be parsed as a label, never as an opcode.</strike>
 
* backend; create a list- and hex-file out of the generated parse tree.
 
* backend; create a list- and hex-file out of the generated parse tree.
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===The 'complex instructions' Problem===
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One challenge in creating an assembler for SX is that the standard assembler knows a few 'complex' instructions that translate into two or more 'primitive' instructions. Extra challenging is that these complex instructions cannot be determined by their opcode alone. A 'mov' instruction, for instance can be primitive (<code>mov w, #10</code>) or complex (<code>mov SomeAddress, #10</code>), which translates into <code>mov w, #10</code> followed by <code>mov SomeAddress, w</code>
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===Status===
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This project is on halt right now.
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[[Category:SX development environment]]

Latest revision as of 22:07, 12 July 2010

I'm toying with the creation of a boost.spirit based SX assembler, written in C++. update: I'm reconsidering writing the grammar of the assembler in ANTLR instead of spirit, so that i could use the same grammar in Java (eclipse) and C++ (tool chain).

The sx assembler consists of 2 parts:

  • frontend; create a syntax tree out of the program text. There is a working spirit grammar without actions (the actual tree building). Open items are:
    • include
    • macros
    • recognizing opcodes that start in the label column (the first column). Currently, a word that starts in the first column will be parsed as a label, never as an opcode.
  • backend; create a list- and hex-file out of the generated parse tree.

The 'complex instructions' Problem

One challenge in creating an assembler for SX is that the standard assembler knows a few 'complex' instructions that translate into two or more 'primitive' instructions. Extra challenging is that these complex instructions cannot be determined by their opcode alone. A 'mov' instruction, for instance can be primitive (mov w, #10) or complex (mov SomeAddress, #10), which translates into mov w, #10 followed by mov SomeAddress, w

Status

This project is on halt right now.