DJGPP

By Wikipedia
DJGPP
Djgpp logo.svg
GCC DJGPP Windows.png
The DJGPP environment, utilizing GCC
Developer(s) DJ Delorie
Stable release 2.0.3p2 / June 10, 2002; 12 years ago (2002-06-10)
Operating system DOS and Windows
Type Compiler
License GNU GPL
Website www.delorie.com/djgpp/

DJGPP (DJ's GNU Programming Platform)[1] is a development suite for 386-based IBM PC compatibles which supports DOS-compatible operating systems. It is guided by DJ Delorie, who began the project in 1989. It is a port of the popular GCC compiler, as well as mostly GNU utilities such as Bash, find, tar, ls, Gawk, sed, and ld to DPMI. Languages available include C, C++, Objective-C/C++, Ada, Fortran, and Pascal.

Design[edit]

The compiler generates 32-bit code, which runs natively in 32-bit protected mode while switching back to 16-bit DOS calls for basic OS support. However, unlike Open Watcom, it is not a zero-based flat model due to preferring NULL pointer protection for better stability. It is currently based upon a variant of the COFF format. It can access up to 4 GB of RAM in pure DOS when using a suitable DPMI host (e.g. CWSDPMI r7 or HDPMI32).

Compatibility[edit]

DJGPP presents the programmer an interface which is compatible with the ANSI C and C99 standards, unofficial DOS standards, and an older POSIX Unix standard. Compiled binaries are long file name-aware and handle such filenames under Win32 by default. TSRs to support LFNs under plain DOS or Windows NT 4 are available.

While DJGPP runs in 32-bit protected mode, its stub and library heavily rely upon many 16-bit DOS and BIOS calls. Because the x86-64 versions of Windows lack support for 16-bit programs,[2] there is no NTVDM, and DJGPP applications cannot be run. Under x86-64 systems these applications function only through emulation (e.g. DOSBox), virtualization (e.g. VirtualBox), or similar (e.g. Linux's DOSEMU). This problem arises because in long mode x86-64 processors do not support the virtual 8086 mode used to run 16-bit code in IA-32 processors. Newer x86 CPUs with VT-x do support paged real mode and unrestricted guest mode execution.[citation needed]

See also[edit]

References[edit]

  1. ^ Eli Zaretskii (Jul 1999). "The DJGPP Project". Retrieved 20 Jul 2009. 
  2. ^ Microsoft (Oct 2007). "List of limitations in 64-Bit Windows". Retrieved 18 May 2010. 

External links[edit]

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