RDOFF
Encyclopedia
RDOFF, the Relocatable Dynamic Object File Format, was born from the need for NASM
NASM (computer program)
The Netwide Assembler is an assembler and disassembler for the Intel x86 architecture. It can be used to write 16-bit, 32-bit and 64-bit programs. NASM is considered to be one of the most popular assemblers for Linux....

 developers to test the integrity of NASM's object file output capabilities. It is based heavily on the internal structure of NASM, essentially consisting of a header containing a serialization
Serialization
In computer science, in the context of data storage and transmission, serialization is the process of converting a data structure or object state into a format that can be stored and "resurrected" later in the same or another computer environment...

 of the output driver function calls followed by an array of sections containing executable code or data. Tools for using the format, including a linker and loader, are included in the NASM distribution.

History

Until version 0.90 of NASM was released in October 1996, NASM only supported output of flat-format executable files (e.g. MS-DOS
MS-DOS
MS-DOS is an operating system for x86-based personal computers. It was the most commonly used member of the DOS family of operating systems, and was the main operating system for IBM PC compatible personal computers during the 1980s to the mid 1990s, until it was gradually superseded by operating...

 COM file
COM file
In many computer operating systems, a COM file is a type of executable file; the name is derived from the file name extension .COM. Originally, the term stood for "Command file", a text file containing commands to be issued to the operating system , on many of the Digital Equipment Corporation mini...

s). In version 0.90, Simon Tatham
Simon Tatham
Simon Tatham is an English programmer known primarily for creating and maintaining PuTTY, a free software implementation of Telnet and SSH clients for Unix and Windows API platforms, along with an xterm terminal emulator...

 added support for an object-file output interface, along with support for DOS .OBJ files for 16-bit code only.

NASM thus lacked a 32-bit object format. To address this lack, and as an exercise to learn the object-file interface, developer Julian Hall put together the first version of RDOFF, which was released in NASM version 0.91.

Since this initial version, there has been one major update to the RDOFF format, which added a record-length indicator on each header record, allowing programs to skip over records whose format they do not recognise, and support for multiple segments; RDOFF1 only supported three segments: text, data and bss (containing uninitialized data).

Projects based on RDOFF

  • RadiOS Operating System
    Operating system
    An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

     Project
  • WDOSX DOS extender
    DOS extender
    A DOS extender is a computer software program which enables software to run under a protected mode environment even though the host operating system is only capable of operating in real mode....

  • SOBS (operating system) Operating System
    Operating system
    An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

    Project

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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