DJ's GNU Programming Platform (DJGPP) is a software development suite for

Intel 80386 The Intel 386, originally released as the 80386 and later renamed i386, is the third-generation x86 architecture microprocessor from Intel. It was the first 32-bit computing, 32-bit processor in the line, making it a significant evolution in ...

-level and above, IBM

PC compatible An IBM PC compatible is any personal computer that is hardware- and software-compatible with the IBM Personal Computer (IBM PC) and its subsequent models. Like the original IBM PC, an IBM PC–compatible computer uses an x86-based central pro ...

s which supports

DOS DOS (, ) is a family of disk-based operating systems for IBM PC compatible computers. The DOS family primarily consists of IBM PC DOS and a rebranded version, Microsoft's MS-DOS, both of which were introduced in 1981. Later compatible syste ...

operating systems. It is guided by DJ Delorie, who began the project in 1989. It is a

port A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Hamburg, Manch ...

of the

GNU Compiler Collection The GNU Compiler Collection (GCC) is a collection of compilers from the GNU Project that support various programming languages, Computer architecture, hardware architectures, and operating systems. The Free Software Foundation (FSF) distributes ...

(GCC), and mostly

GNU GNU ( ) is an extensive collection of free software (394 packages ), which can be used as an operating system or can be used in parts with other operating systems. The use of the completed GNU tools led to the family of operating systems popu ...

utilities such as Bash, find,

tar Tar is a dark brown or black viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. "a dark brown or black b ...

, ls, G AWK, sed, and ld to

DOS Protected Mode Interface In computing, the DOS Protected Mode Interface (DPMI) is a specification introduced in 1989 which allows a DOS program to run in protected mode, giving access to many features of the new PC processors of the time not available in real mode. It w ...

(DPMI). Supported languages include C, C++,

Objective-C Objective-C is a high-level general-purpose, object-oriented programming language that adds Smalltalk-style message passing (messaging) to the C programming language. Originally developed by Brad Cox and Tom Love in the early 1980s, it was ...

/C++, Ada, Fortran, and Pascal. It was originally called DJGCC, and was later renamed from DJGCC to DJGPP when C++ support was added, though the "PP" was said to stand for "Programming Platform" rather than "Plus Plus".

Overview

The compiler generates 32-bit code, which runs natively in 32-bit

protected mode In computing, protected mode, also called protected virtual address mode, is an operational mode of x86-compatible central processing units (CPUs). It allows system software to use features such as Memory_segmentation, segmentation, virtual mem ...

while switching back to 16-bit DOS calls for basic OS support. However, unlike the Open Watcom C/C++ compiler, 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 The Common Object File Format (COFF) is a format for executable, object code, and shared library computer files used on Unix systems. It was introduced in Unix System V, replaced the previously used a.out format, and formed the basis for ext ...

format. It can access up to 4 GB of RAM in pure DOS when using a suitable DPMI host (e.g.,

CWSDPMI CWSDPMI is a 32-bit DPMI host written by Charles W. Sandmann from 1996 to 2010, currently at r7. It is loosely based upon prior GO32.EXE code used in DJGPP v1. It can provide DPMI 0.90+ 32-bit services for programs compiled with latest versions o ...

r7 or HDPMI32). , main components of DJGPP 2 include: *

9.3.0 (10.2.0, 12.2.0 and 14.2.0 are also available, among other versions) *

Autoconf GNU Autoconf is a software development tool for generating a configure script that in turn generates files for building a codebase and for packaging or installing the resulting files. Autoconf is part of the GNU Build System along with Autom ...

2.5.9 *

Automake GNU Automake is a software development tool to automate parts of the compilation process. It eases common compilation problems. For example, it points to needed dependencies. It automatically generates one or more ''Makefile.in'' from files call ...

1.9.4 *

Binutils The GNU Binary Utilities, or , is a collection of programming tools maintained by the GNU Project for working with executable code including assembly, linking and many other development operations. The tools are originally from Cygnus Solut ...

2.35.1 *

GNU Bash In computing, Bash (short for "''Bourne Again SHell''") is an interactive command interpreter and command programming language developed for UNIX-like operating systems. Created in 1989 by Brian Fox for the GNU Project, it is supported by the Fre ...

4.4 * GNU Bison 2.4.1, Flex 2.5.4 *

GNU Emacs GNU Emacs is a text editor and suite of free software tools. Its development began in 1984 by GNU Project founder Richard Stallman, based on the Emacs editor developed for Unix operating systems. GNU Emacs has been a central component of the GNU ...

29 * GNU MPC 1.1.0, MPFR 4.1.0 It is also possible to use DJGPP to cross-compile software to DOS, for example on UNIX / Linux. Both the DJGPP libraries and the programs can be compiled this way, linked and then deployed to machines with DOS or DOS emulators.

Compatibility

DJGPP presents the programmer an interface which is compatible with the

ANSI C ANSI C, ISO C, and Standard C are successive standards for the C programming language published by the American National Standards Institute (ANSI) and ISO/IEC JTC 1/SC 22/WG 14 of the International Organization for Standardization (ISO) and the ...

and

C99 C99 (previously C9X, formally ISO/IEC 9899:1999) is a past version of the C programming language open standard. It extends the previous version ( C90) with new features for the language and the standard library, and helps implementations mak ...

standards, DOS APIs, and an older

POSIX The Portable Operating System Interface (POSIX; ) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines application programming interfaces (APIs), along with comm ...

-like environment. Compiled binaries are

long filename Long filename (LFN) support is Microsoft's backward-compatible extension of the 8.3 filename (short filename) naming scheme used in MS-DOS. Long filenames can be more descriptive, including longer filename extensions such as .jpeg, .tiff, an ...

(LFN) aware and can handle such names under most 32-bit Windows by default, but they cannot use the

Win16 The Windows API, informally WinAPI, is the foundational application programming interface (API) that allows a computer program to access the features of the Microsoft Windows operating system in which the program is running. Programs can acces ...

or Win32 APIs that graphical programs on Windows need.

terminate-and-stay-resident A terminate-and-stay-resident program (commonly TSR) is a computer program running under DOS that uses a system call to return control to DOS as though it has finished, but remains in computer memory so it can be reactivated later. This technique ...

(TSR) programs to support LFNs under plain

Windows NT 4 Windows NT 4.0 is a major release of the Windows NT operating system developed by Microsoft, targeting the data server and personal workstation markets. It is the direct successor to Windows NT 3.51, and was released to manufacturing on July ...

are available. While DJGPP runs in 32-bit

, its stub and library heavily rely on many 16-bit DOS and BIOS calls. Because the

x86-64 x86-64 (also known as x64, x86_64, AMD64, and Intel 64) is a 64-bit extension of the x86 instruction set architecture, instruction set. It was announced in 1999 and first available in the AMD Opteron family in 2003. It introduces two new ope ...

versions of

Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

lack support for 16-bit programs, there is no

NTVDM Virtual DOS machines (VDM) refer to a technology that allows running 16-bit/32-bit DOS and 16-bit Windows programs when there is already another operating system running and controlling the hardware. Overview Virtual DOS machines can operate e ...

, and DJGPP applications cannot be run. Under x86-64 systems these applications function only through emulation (e.g.

DOSBox DOSBox is a free and open-source MS-DOS emulator. It supports running programs primarily video games that are otherwise inaccessible since hardware for running a compatible disk operating system (DOS) is obsolete and generally unavailab ...

x86 virtualization x86 virtualization is the use of hardware-assisted virtualization capabilities on an x86/x86-64 CPU. In the late 1990s x86 virtualization was achieved by complex software techniques, necessary to compensate for the processor's lack of hardware ...

(e.g.

VirtualBox Oracle VirtualBox (formerly Sun VirtualBox, Sun xVM VirtualBox and InnoTek VirtualBox) is a hosted hypervisor for x86 virtualization developed by Oracle Corporation. VirtualBox was originally created by InnoTek Systemberatung GmbH, which was ac ...

), or similar (e.g. Linux's

DOSEMU DOSEMU, stylized as dosemu, is a compatibility layer software package that enables DOS operating systems (e.g., MS-DOS, DR-DOS, FreeDOS) and application software to run atop Linux on x86-based PCs (IBM PC compatible computers). Features It ...

). This problem arises because in

long mode In the x86-64 computer architecture, long mode is the mode where a 64-bit operating system can access 64-bit instructions and registers. 64-bit programs are run in a sub-mode called 64-bit mode, while 32-bit programs and 16-bit protected mod ...

x86-64 processors do not support the

virtual 8086 mode In the 80386 microprocessor and later, virtual 8086 mode (also called virtual real mode, V86-mode, or VM86) allows the execution of real mode applications that are incapable of running directly in protected mode while the processor is running ...

used to run 16-bit code in IA-32 processors. Newer x86 CPUs with

VT-x x86 virtualization is the use of hardware-assisted virtualization capabilities on an x86/x86-64 CPU. In the late 1990s x86 virtualization was achieved by complex software techniques, necessary to compensate for the processor's lack of hardware-a ...

do support paged real mode and unrestricted guest mode execution.

References

External links

* {{official website, www.delorie.com/djgpp
DJ Delorie's webpage
1989 software C (programming language) compilers DOS extenders Free and open source compilers Free integrated development environments

Overview

Compatibility

See also

References

External links