path: root/doc/ports/notes.linux

Begin Sat Apr 29 21:05:25 MST 1995  Linux 1.1.93.
Files actually set up initially last weekend.
-----------------------------------------------------

unix/hlib/irafuser.csh MACH is "linux", architecture is "linux" compiler is
	GCC.  Set up generic compile and link flags for the moment.  (4/23)

unix/hlib/mach.h
	x86 boxes are little-endian so all the SWAP flags are set to YES
	on this platform.  (4/23)

unix/os/mkpkg.sh
	1. Was using HSI_LIBS to link alloc.e, but the iraf libraries are not
	used in this file.  Changed to use HSI_OSLIBS instead.
	2. Deleted the reference to as$enbint.s, not used for Linux.  (4/29)

(linux)
	1. After booting typing "cd unix", which uses cdpath to go to
	$iraf/unix, would hang the xterm.  The problem went away following
	a reboot.
	2. Got a bunch of failures to compile when doing a reboot of the 
	HSI, no apparent reason (message said couldn't write .o files).
	Started another reboot and the problem went away.
	3. Manpages can be very brief and do not fully specify system or
	library routines.
	4. Problems with cut and past, not resolved.

unix/os/zfiomt.c
	The structure "mtpos" used in this file redefines a different
	structure defined in <sys/mtio.h>.  Changed zfiomt.c to use _mtpos
	for its internal structure.  (4/30)

unix/os/zfiomt.c
	Linux doesn't have SIGEMT.  Changed to use SIGABRT.  (4/30)

unix/os/mkpkg
	Commented out enbinit.s.  (4/30)

unix/boot/gdev/sgidev/sgi2uapl.c
	Added a #undef SOLARIS to cause the routine to use gethostname()
	rather than sysinfo which is implemented differently in Solaris 
	and Linux.  (4/30)

unix/hlib/install
	Minor changes for Linux.  (4/30)

unix/hlib/motd
	Modified for Linux/IRAF V2.10.4BETA.  (4/30)

unix/boot/mkpkg/host.c
	Added #undefs for SYSV and i386 to cause this code to use ranlib.
	(4/30)

----------------------------------------------
Completed HSI bootstrap.  (4/30)

unix/hlib/mkpkg.inc
unix/hlib/mkpkg.sf.LINUX	+
	Modified mkpkg.inc for Linux, no compile/link flags of note yet at
	this point.  Add a base special file list for Linux, currently only
	references the C files in AS.  (4/30)

unix/boot/spp/xc.c
	Modified the code which compiles "other" files (not .x or .f) to
	explicitly compile only .c and .s files.  This prevents unrecognized
	command line flags from confusing the code and causing a command to
	be issued that contains nothing to be compiled.  (5/03)

(linux)
	Another Linux oddity with libraries: on linking the CL _zawrim_ would
	always come up undefined, even though an "ar tv" of libds.a showed
	it looked fine.  Deleting zawrim.o and updating the library made the
	problem go away.  (5/03)

unix/os/zfiond.c
	Added a #include <sys/time.h>, needed to pick up the FD_SET etc.
	definitions on Linux.  (5/03)

unix/as.linux/ieee.gx
	Installed the little-endian version (from OSF/1).  F2C complained
	about statements following DATA so I had to rearrange the code in
	ieemap$t a bit.  (5/03)

unix/hlib/cl.csh
unix/hlib/fc.csh
	Deleted the uname stuff and just fixed MACH=linux.  Added linux
	case code where needed.  (5/03)


unix/as.linux/zsvjmp.s
	I had to change the reference to `__setjmp' to `___setjmp' (3 under-
	scores) to get the routine to call the function `__setjmp'.  (5/03)

unix/os/zawset.c
unix/hlib/libc/kernel.h
	Installed the zawset (begmem) changes from tucana.  (5/03)


Begin Sat Jul 22 20:24:16 MST 1995
The Linux port was set aside for a time while IRAF V2.10.4 was prepared
and our Linux system was upgraded to Slackware 2.3 and Linux 1.2.11.
The port is being redone using Solaris/IRAF V2.10.4.  The above revisions
will be merged before we resume taking notes.
---------------------------------------------------------------------------

unix/hlib/spy.cl
	Added a Linux clause and set this to use "ps -axuf" for Linux.  The
	"-f" option provides a parent/child ordering similar to sps.  (7/22)

unis/os/zawset.c
	Added an ifdef for Linux to cause it to uset {set|get}rlimit.  (7/22)

unix/os/zgtime.c
	Modified to use CLK_TCK (100 Hz), as on Solaris.  (7/22)

unix/os/zpanic.c
	Use SIGABRT on Linux rather than SIGEMT, which doesn't exist.
	The Linux documentation doesn't specify which signals cannot be
	caught, hopefully ABRT will do it.  (7/22)

unix/boot/mkpkg/host.c
	Linux uses the GNU "ar" to maintain object libraries.  This turns out
	to have a bug which prevents it from properly updating a library which
	is a symbolic link to the actual library.  The library is updated in
	the current directory, and the symbolic link is replaced by the
	updated library, hence the actual (remote) library is never updated.
	To work around this a new internal function "resolvefname" was added
	to host.c  This back traces any symbolic links and returns a fully
	resolved library name.  (7/24)

unix/os/zxwhen.c
	I noticed during testing that when interrupting the cl or a task
	run stand alone, while waiting for command input, that following
	the interrupt processing the most recent block of input would be
	reread and executed.  Evidently what happens is that Linux stdio
	partially initializes the stdin file descriptor before the read,
	and then never finishes initializing it since the read is interrupted
	and never returns (in other words no critical section protection for
	stdio).  The workaround was to extend the fcancel() macro in zxwhen
	to reset both the input and output buffer pointers, and add a fcancel
	for stdin to the error handler to cancel the input buffer if an
	interrupt occurs.  (7/24)

unix/os/zzstrt.c
unix/os/zxwhen.c
	These routines were further modified to implement exception handling
	for Linux.  This turned out to be hard to do properly as about all
	Linux provides is a simple signal() interface.

	1. The first problem was that interrupts were being disabled after
	the first interrupt, as signals are "one-shot" by default.  The fix
	here was to re-register the signal handler after each signal, and
	to reinitialize the FPU control register during process startup and
	during exception recovery.

	2. After getting some Intel hardware manuals and some time digging
	around in the Linux kernel to see how signals are handled I finally
	found that the kernel pushes a frame on the stack before entering the
	user exception handler.  The EBP register can be used to get the
	address of this frame.  This frame describes the cpu state at the
	time that the exception occurred and includes the hardware trap
	number.  This is sufficient to identify all system traps but only
	identifies floating point exceptions to the coprocessor trap level.
	The floating point unit status register has been cleared by the time
	the user exception handler is entered and so far I haven't discovered
	how to differentiate the floating point exceptions, but at least
	things like the integer divide by zero and overflow exceptions are
	properly diagnosed.  The kernel is saving the information on the
	FPU status internally, but so far I haven't found out how to access
	this information from the application.  (7/29)

unix/boot/spp/xc.c
	The f77 command on Linux, which is a shell script based on F2C,
	erroneously returns an exit status of 4 when successfully compiling
	a Fortran file.  This would cause commands such as "xc foo.x" to
	fail to link the output program thinking that the compilation had
	abort on an error.  To workaround this bug XC was modified to ignore
	an exit status of 4 when calling f77 under Linux.  (7/30)

unix/os/zgcmdl.c
	Linux also uses xargc,xargv.  (7/30)

dev/termcap
	Added "lp" alias for "lpr", as used in zzsetenv.def.  (7/30)

-------------------------
Downloaded and built TABLES without incident.  (8/01)
Built NOAO packages without incident.  (8/01)

unix/os/zmain.c
	Changed the call to exit() to _exit() for Linux.  I was having trouble
	with tasks in NOAO and TABLES doing horrible things during process
	shutdown (hanging up the console for minutes with the disk thrashing
	heavily, or doing a panic shutdown).  Although I did not check it out
	fully, this appeared to be due to an "onexit" feature of the GNU exit() calling
	calling random parts of process memory with essentially unpredicable
	results.  The simplest solution was to simply use _exit instead, which
	avoids this feature.  (8/01)

unix/hlib/f77.sh		+
	Copied the default "f77" script that comes with Linux to $hlib/f77.sh.
	The script was modified to eliminate the "f2ctmp_" prefix that it was
	prepending to Fortran file names before compiling with GCC.  This
	feature (used by the script to implement Fortran includes) breaks 
	source code debugging since the file which is actually compiled has
	the f2ctmp prefix and this file no longer exists after compilation.
	This fix also eliminated the "exit 4" problem mentioned above in the
	xc.c fix.  (8/02)

unix/boot/spp/xc.c
	Modified XC to use the f77.sh script as the Fortran compiler, instead
	of "f77".  It will still fall back and use f77 if it can't find
	f77.sh.  (8/02)

unix/hlib/f77.sh
	1. Modified so that the -w flag inhibits warning messages from both f2c
	and gcc.  This is necessary to get rid of a few warning messages seen
	when compiling the IRAF code which do not indicate any real problems.
	2. Added a call to sed in the f2c call to workaround a bug in f2c
	where -w fails to strip out all the lines of a multiline warning
	message.  (8/02)

-----------------
Wed Aug 16 13:00:13 MST 1995
System has been in testing since last thursday.

dev/tapecap
	Modified this file for Linux.  Linux has a nice tape interface
	supporting variable block sizes, behavior is very standard, however
	there is no support for compression or any non-generic tape features,
	and the default maximum block size on a read is 32K.  (8/15)

local/
	Installed a Linux specific set of startup files for the IRAF
	account.  (8/24)

mkpkg
noao/mkpkg
	Added "linux" targets.  (8/28)

unix/hlib/irafuser.csh
	Added "-static" to the link flags for the HSI.  (8/28)

unix/os/zfiotx.c
	Added #ifdef LINUX code in a couple of places to cancel the input
	stream if an interrupt occurs (workaround for same bug as in zxwhen
	above).  (9/02)

---------------------------------------
Installed V2.10.4 patch1.  Bootstrap, sysgen-update.  (9/02)

unix/hlib/install
	Added "chmod -t /tmp" to allow multiuser deletion of files, e.g.
	magtape lock files, in /tmp.  (9/03)

local/*
	Configured the login files for the IRAF account, including setting
	up the window system.  Installed gzexe-compressed binaries for xgterm,
	ximtool, and the tin newsreader in $iraf/local/bin.  Set up window
	system to start up by default 5 seconds after logging in, using fvwm
	as the window manager.  An "ADASS news" entry in the root menu accesses
	the ADASS news using the tin executable provided.  (9/03)

unix/boot/bootlib/osfiletype.c
	Added ".gz" to the list of source file types.  (9/03)

doc/rev2.hlp
	Renamed this file to rev2.txt, it is not a help file.  (9/03)

unix/hlib/strip.iraf
noao/lib/strip.noao
	Various minor enhancements and updates.  (9/03)

bin.linuz		+
noao.bin.linuz		+
unix/hlib/cl.csh
mkpkg
noao/mkpkg
	Added a new architecture "linuz", which is a gzexe (gzip compressed)
	version of bin.linux.  (9/03)

----------------------------------------------------------------
V2.10.4 Linux/IRAF release cut.  (9/04)

unix/hlib/install
	Deleted reference to edsym.e, which is not used on Linux/IRAF.  (9/18)

unix/boot/rtar/rtar.c
	RTAR would immediately die on a segvio.  This was traced to the use
	of a local variable "setuid" which evidently conflicts with some
	Linux include file definitions.  Changed a number of local variables
	in the program to static local variables and this fixed the problem.
	(9/20)

unix/hlib/f77.sh
	Added a -b flag to allow calling f77 with the "-b i486-linuxaout" flag
	to build a.out executables on ELF systems.  (1/03/96)

unix/hlib/irafuser.csh
	Added "-b -i486-linuxaout" to the HSI compile and link flags.  (1/03)

unix/boot/spp/xc.c
	Added "-b -i486-linuxaout" flags to all compile and link instances.
	(1/03)

unix/bin.linux/libf2c.a		+
	Added a copy of the a.out version of libf2c.a to HBIN since this is
	not present on Slackware ELF systems, and possibly other Linux
	verisons.  (1/03)

unix/os/mkpkg.sh
	Changed the call to "as" to use $CC -c $HSI_CF instead, to cause any
	platform specific flags to be used to assemble the files.  (5/29 1996)


----------------------------
TODO

*** Provide sh/bash equivalent of irafuser.csh.

Wed May 29 11:11:00 MST 1996
	New version of spp/xpp/xppcode.c does not work on Linux - some problem
	with tokens.  Using old version for now.