This is the README file for DJ's GCC port to DOS ("djgpp")
* What's available
* How to install
* Deviations and Caveats
* Copyright information
Disclaimer: This software is distributed WITHOUT ANY WARRANTY; without
even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
USmail: 24 Kirsten Ave, Rochester, NH 03867-2954, USA
email: [email protected]
mailing list: [email protected]
This package contains a 32-bit 80386 DOS extender with symbolic
debugger, a C/C++ compiler with utilities, development libraries, and
source code. It generates full 32-bit programs and supports full
virtual memory with paging to disk.
A 80386-based IBM compatible PC or PS/2, approximately 4-5Mb of hard
drive space, and 512K RAM. Available extended (or expanded under VCPI)
memory is strongly recommended.
* Up to 128M of extended memory (expanded under VCPI)
* Up to 128M of disk space used for swapping
* SuperVGA 256-color mode up to 1024x768
* XMS & VDISK memory allocation strategies
* VCPI programs, such as QEMM, DESQview, and 386MAX
* Microsoft Windows
* Multiprocessing (fork())
password: send your e-mail address
Many thanks to the sysops at Clarkson for providing a home to djgpp!
As a convenience to non-FTP users, djgpp is also stored on Clarkson's
archive server. To access the archive server, do this:
% mail [email protected]
NOTE: In accordance with FSF CopyLeft, you are not allowed to upload
this program to a distribution site unless that site also makes the FSF
sources for these programs available. Please read the file COPYING for
more details. FSF sources are available on prep.ai.mit.edu, and on
NOTE: If your application links in object modules that were written
by FSF, your application counts as a "derived work" and must obey
the provisions of the FSF Copyrights. See the file COPYING for
details. Specifically, the C++ classes in libc.a and obstacks are
FSF works that are covered by the GNU GPL. The mere act of compiling
does not affect the copyright status of your program.
To install, you must do the following:
* Create a "temp" directory, like c:\tmp.
* Create a directory to install in, like c:\djgpp.
* Un-zip the appropriate zipfiles in the install directory.
C:\DJGPP> pkunzip -d -o djdev109.zip
C:\DJGPP> pkunzip -d -o djgas138.zip
C:\DJGPP> pkunzip -d -o djgcc222.zip
* Add the following lines to C:\CONFIG.SYS file (or edit existing
files= and shell= lines as appropriate). The files= line prevents "too many
open files" errors when compiling, and the shell= line prevents "Out of
environment space" errors when setting lots of environment variables.
shell=c:\command.com c:\ /e:600 /p
The values 15 and 600 are close to minimal. You may want to increase them
to provide a little more margin.
* Add the following lines to C:\AUTOEXEC.BAT:
^^^ only needed if you are compiling c++ programs
^^^ only needed if you are compiling objective-C programs
^^^ only needed if you are compiling objective-C++ programs
^^^ this is where gcc's temp files go
^^^ this is where your paging file goes - if not set, the
variables TMP and TEMP are checked in that order
set GO32=ansi driver c:/djgpp/drivers/SOMETHING.grd gw 1024 gh 768
^^^ whatever driver works with your VGA (optional)
^^^ only needed if you use bison
^^^ only needed if you use bison
^^^ only needed if you use flex
Remember that unless you manually type these at the command line,
they won't take effect until you reboot. Don't include the "ansi"
keyword in the "go32" variable if you don't have an ANSI.SYS driver
* Add your binaries directory to your PATH in C:\AUTOEXEC.BAT
SET PATH= . . . ;C:\DJGPP\BIN
That's it! djgpp is now installed on your system.
The GO32 environment variable:
This variable controls the options available in go32 or debug32. The
syntax of this variable is:
SET GO32=[parm [value]] [parm [value]] . . .
ansi Use ANSI commands to control the color in debug32
mono Use the Monochrome monitor for debugging - useful when
debugging graphics applications
1rm Redirect stdout (file #1) to the monochrome monitor
2rm Redirect stderr (file #2) to the monochrome monitor
1r2 Redirect stdout (file #1) to stderr (file #2)
2r1 Redirect stderr (file #2) to stdout (file #1)
glob enable globbing (default)
noglob disable globbing
emu [path] Use the specified file as the 80387 emulator
driver [path] Use the specified file as the graphics driver
gw [width] Default graphics width
gh [height] Default graphics height
tw [width] Default text width
th [height] Default text height
nc [colors] Number of colors (for new-style drivers only - see cbgrx*.zip)
These parameters may occur in any order.
Note that "1rm" and "2rm" are done before "1r2" and "2r1", so "1rm 2r1" sends
stdout to the mono monitor and stderr to any redirection used.
C:\> set GO32=mono driver c:\djgpp\drivers\tseng4k.grd gw 1024 gh 768 tw 132 th 43 nc 256
C:\> set GO32=ansi
C:\> set GO32=driver c:\djgpp\drivers\tseng4k.grd ansi
C:\> set GO32=mono 1rm 2rm
Deviations and Caveats:
GCC/G++ deviates from the U**x version in a number of ways, mostly to
accomodate deficiencies in the MS-DOS environment, and my own laziness.
* An 80387 is required to do floating point. An emulator is provided.
cc1 and cc1plus shouldn't use the 387 unless compiling floating point
code. The environment variable "387" can override the auto-detection
SET 387=YES to force 387 handlers to be enabled
SET 387=NO to force 387 accesses to fault
SET 387=QUERY to get a message showing the results of the auto-detection
If no 80387 is present and the program attempts to use it, a message
indicating where the instruction is will be displayed. To use the
387 emulator, add "emu c:\djgpp\emu387\emu387" to the GO32 environment
variable. Specifying use of the emulator overrides the "387"
environment variable and autodetection code.
* The VDISK method of allocating extended memory is supported. The
INT 15h method is also. When the extender runs out of conventional and
extended memory, it uses a paging file named $(GO32TMP)/pgXXXXXX.386, where
XXXX is an unspecified hex value. This file is normally removed on exit.
* Up to 128 MB of physical memory and 128 MB of disk swap space are allowed.
A 512K machine is sufficient, but very slow due to paging.
* The utilies support the MS-DOS standard response file method for giving
more than 128 bytes of command line. Example: "gcc -o foo @foo.lnk" where
foo.lnk contains a list of .o files. Wildcard expansion (globbing) is
performed on the parameters, unless they are surrounded by single quotes.
Double quotes can be used to prevent spaces from separating arguments.
Also supported is the GNUish-DOS method of passing arguments in
* Since MS-DOS does not distinguish case in file names, some .h files
used for C++ have had underscores prepended to them to avoid conflict
(ie: String.h conflicts with string.h, so it became _String.h).
* When using ar to create archives, be warned that the ar version
supplied cannot update an archive that's been sequenced (ar s foo.a),
and cannot sequence a file that's been sequenced. Also, ld cannot
use an archive that's not sequenced. The following method is suggested:
ar rv mylib.a $(OBJS)
cp mylib.a mylib2.a
ar rvs mylib2.a
(and then link with mylib2.a)
* The extender can be added to any gcc-compiled program by copying go32.exe
to be .exe, where is the 32-bit program. For example,
if "hello" is a gcc-compiled a.out file, and "hello.exe" is a copy of
go32.exe, then when "hello.exe" runs, it loads the file called "hello"
in the same directory, and executes it if present. Otherwise,
the first parameter is the executable (ie: go32 cc1plus foo.cc).
* The extender can be merged to create one .exe file that is the extender
and the executable in one file, by using the stub.exe program:
copy /b stub.exe+myprog myprog.exe
This will only work if go32.exe is in your search path, because stub.exe
runs it. Alternatively, you can prepend go32.exe itself to an a.out file
to get a single executable (stub.exe is much smaller). Note that if
you re-compile go32 or stub, you must strip off the symbol table first.
* The extender runs programs at logical address 0. A copy of the first
1 MB of physical memory (including the AT channel) is mapped to
0xE0000000 in the program's address space. The stack grows down from
0x7FFFFFFC in the program's address space. Data usually starts at
* The paging mechanism understands how SuperVGA's map their memory onto
the AT bus and automatically swaps pages as the program tries to
access them. The program sees a linear range from 0xD0000000 to
0xD0100000 that corresponds to each pixel in the 256-color modes
of SuperVGAs. To use this feature, you'll have to set the GO32
environment variable like this:
C>set go32=driver c:\djgpp\drivers\tseng4k.grd gw 640 gh 480 tw 132 th 43
These parameter pairs can be omitted or rearranged as needed. They are
the "driver" name, default graphics width and height, and default
text width and height. Libgr.a doesn't have to be recompiled, nor
do graphics programs, when a different graphics mode is selected
(the extender handles it). It is strongly recommended that the program
use the GR_default_graphics and GR_default_text modes to switch to
graphics or text. These modes use the parameters specified by the
GO32 environment variable, allowing the user to select a favorite
graphics and text mode.
* Symbols are stored in virtual memory, so you won't run out of symbol
space until both extended memory and the disk are all used up. For
large programs, you might notice a slight delay while it looks up
symbols. Programs with a lot of lines in a given module may run out
of memory as the line number table is built in real memory and transferred
to virtual memory.
* Signals are not reported to the program. However, interrupts do continue
to get serviced while in protected mode (ie: keypress, timer, etc).
CTRL-C will get you back to the debugger in debug32, and you can continue
from where you stopped. All signals (ie: exceptions) cause debugging
traps in debug32, or general faults in go32.
* Source code for the GNU utilities is copyright (c) Free Software Foundation.
For more information on the FSF copyright, see their source code or write
Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
A copy of their file "COPYING" is included in the docs directory. Some of
the FSF source code has been modified to operate properly in the MS-DOS
* Source code for most of libc.a are copyright (c) Regents of the University
of California. These files include copyright information in them. The
utilities are compiled against these libraries, and thus contain software
developed by the University of California, Berkeley, and its contributors.
Some of the BSD source code has been modified to operate properly in the
* Any sources not falling under the copyrights of FSF or UCB (as above) are
Copyright (c) 1991 DJ Delorie, 24 Kirsten Ave, Rochester NH 03867-2954.
To contact me via E-Mail, sent to "[email protected]". Cabletron Systems Inc
is in no way involved with this project; I just happen to work for them
during the day.
Terms and Conditions:
* Source code copyright FSF is distributed under the terms of the GNU
Public General License. See the file "COPYING" in doc.arc for more
information. If your program links in object modules (in libc.a) that
are compiled from GNU sources, then your entire program must be
distributed under the terms of the GNU GPL as a "derived work". These
modules are the C++ class library (including the streams classes) and
obstacks. The sources in libsrc have the copyright notices in them
for the various modules.
* Source code copyright UCB is distributed under the terms listed in the
UCB source code itself.
* Source code copyright DJ Delorie is distributed under the terms of the
GNU General Public Licence, with the following exceptions:
("go32.exe" refers to go32.exe and debug32.exe)
* There are no conditions on distributing copies of stub.exe or emu387
as they are originally distributed in this software package.
* If a user creates an application, prepends a copy of go32.exe onto
the beginning of it, and distributes it free of charge, then the
user is under no obligations to distribute source or pay royalties.
Note that the copyright terms of the FSF and/or UCB must be
obeyed regardless of this.
* If a user creates an application, prepends a copy of go32.exe onto
the beginning of it, and charges a fee for the software, then a
royalty of $5 or 5% of the selling price per copy sold must be paid
to DJ Delorie, 24 Kirsten Ave, Rochester NH 03867-2954. Note that
shareware programs are not considered "sold" until payment is rendered
* For all other cases, source code for go32.exe must be distributed
with any distributed copies of go32.exe, or made available as per
the terms of the GNU GPL. In these cases, no royalties are due,
and all freedoms provided by the GPL apply.
* Software that requires go32.exe to run, but is not distributed with
a copy of go32.exe, incurs no obligations with regards to the
* Contact me for special terms if none of the above are suitable.
* Donations are always appreciated.
The intent of this copyright is this: If you make money by using the
programs I wrote, I get some of it. If you use your sources to
teach others how to write programs, I'll support you.
Changes to source code copyright BSD or FSF are copyright DJ Delorie, but
fall under the terms of the original copyright.
Donations may be made to any of the following:
24 Kirsten Ave
Rochester, NH 03867-2954
Free Software Foundation
675 Mass Ave
Cambridge, MA 02139
Computer Systems Research Group
Computer Science Division, EECS
University of California
Berkeley, California 94720