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106 lines
4.1 KiB
Plaintext
106 lines
4.1 KiB
Plaintext
Subject: [ANN] 6502 reloc. binaries & assembler
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Newsgroups: comp.sys.cbm,comp.emulators.cbm,comp.sys.atari.8bit,comp.sys.apple2.programmer,comp.arch.embedded
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Organization: TU Chemnitz
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Summary: Announcement of 6502 relocatable binary format and assembler
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Keywords: 6502, 65816, relocation, cross assembler, assembler, file format
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relocatable binary file format o65
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& 6502 cross assembler xa65
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This is the announcement for the 6502 relocatable binary file format 'o65'.
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This format allows to
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- relocate (i.e. move to a different address) a file when loading it, to
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be able to execute at a different address
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- produce global label lists, i.e. being able to export labels from one
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file to another
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- have undefined references, i.e. allow late binding (resolving symbols
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at load time)
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- code sharing in virtual memory architectures
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- do block oriented transfer and have minimum side storage when loading a file
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The format works for the 6502 and for the 65816 CPU. It knows object from
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executable files and more.
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The file format itself is free (I can do the clearance, if you have
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suggestions for extensions etc.)
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Have a look at: http://www.tu-chemnitz.de/~fachat/c64/xa/fileformat.txt
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About another 6502 file format, see note 1).
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6502 cross assembler xa65
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As reference assembler to produce this kind of code, I have implemented
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the file format in my 6502 cross assembler "xa65".
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From version 2.1.1 it supports the new file format standard, and from
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version 2.1.2a, it comes with the "file65", "reloc65" and
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"ld65" utilities to print information about a file, relocate a file
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and link several object files together resp.
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All the programs are close to production stage (you never know if you
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got all bugs...), while the linker is in beta stage. Esp. I want to know
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about options you would like to have.
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The assembler is under GNU public license and can be found at:
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http://www.tu-chemnitz.de/~fachat/c64/xa/index.html
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Other changes from earlier versions:
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- supports o65 file format, including linker, relocator and file utility.
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- much better code quality (only two warnings with
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gcc -W -Wall -pedantic -ansi)
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- supports more MASM pseudo opcodes (but still not the important ones
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that I have my C-like preprocessor for: .if, .macro, .include.
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This might change someday...
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- DOS support by go32 cross-compiling (only Makefile changes!)
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General description:
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- C-like Preprocessor to make macros
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- label "hiding" on different levels,
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i.e. multiple use of the same label possible
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- 1.5-pass assembler:
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Everything that can be derefenced is being assembled in pass 1 and
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saved in memory. The second pass does the rest. This (together
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with hashing etc) gives quite a good speed (30kByte binary out of
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300kByte source in less than two minutes on an 8MHz Atari ST -
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hey, the first versions would have taken half an hour for this
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job! - my 486DX4/100 with linux needs around two seconds or so...)
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- needs no linker - all stuff is in source code (with this speed,
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it's ok)
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- (optional) support for relocatable 'o65' file format,
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including linker, relocator and file utility. A loader in 6502
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assembly code is also included.
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- reads DOS and Unix(tm) files (LF or CR+LF)
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so long
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Andr<EFBFBD> Fachat
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----
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1) There is already another relocatable object file format, called "OMF",
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which is mostly used in the Apple community. I didn't take this format
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for my projects for several reasons: It has some limits on filename
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lengths; the relocation information is encoded between assembler code,
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i.e. one cannot easily use block loading; it doesn't provide different
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segments (as I can see) that have this meaning.
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The OMF file format has never been published on the internet and mostly
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commercial companies from the Apple world seem to support it - but then
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they even have C compilers for this file format.
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--
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Andr<EFBFBD> Fachat |"I do not feel obliged to believe that the
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Institute of physics, | same God who has endowed us with sense,
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Technische Universit<69>t Chemnitz | reason, and intellect has intended us to
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http://www.tu-chemnitz.de/~fachat | forego their use" -- Galileo Galilei
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