mirror of
https://github.com/torvalds/linux.git
synced 2025-11-04 10:40:15 +02:00
59dd24d32c
This fixes a typo and rearranges the sentence to make more sense. Signed-off-by: Shaun Zinck <shaun.zinck@gmail.com> Signed-off-by: Adrian Bunk <bunk@kernel.org>
396 lines
11 KiB
Text
396 lines
11 KiB
Text
Java(tm) Binary Kernel Support for Linux v1.03
|
|
----------------------------------------------
|
|
|
|
Linux beats them ALL! While all other OS's are TALKING about direct
|
|
support of Java Binaries in the OS, Linux is doing it!
|
|
|
|
You can execute Java applications and Java Applets just like any
|
|
other program after you have done the following:
|
|
|
|
1) You MUST FIRST install the Java Developers Kit for Linux.
|
|
The Java on Linux HOWTO gives the details on getting and
|
|
installing this. This HOWTO can be found at:
|
|
|
|
ftp://sunsite.unc.edu/pub/Linux/docs/HOWTO/Java-HOWTO
|
|
|
|
You should also set up a reasonable CLASSPATH environment
|
|
variable to use Java applications that make use of any
|
|
nonstandard classes (not included in the same directory
|
|
as the application itself).
|
|
|
|
2) You have to compile BINFMT_MISC either as a module or into
|
|
the kernel (CONFIG_BINFMT_MISC) and set it up properly.
|
|
If you choose to compile it as a module, you will have
|
|
to insert it manually with modprobe/insmod, as kmod
|
|
cannot easily be supported with binfmt_misc.
|
|
Read the file 'binfmt_misc.txt' in this directory to know
|
|
more about the configuration process.
|
|
|
|
3) Add the following configuration items to binfmt_misc
|
|
(you should really have read binfmt_misc.txt now):
|
|
support for Java applications:
|
|
':Java:M::\xca\xfe\xba\xbe::/usr/local/bin/javawrapper:'
|
|
support for executable Jar files:
|
|
':ExecutableJAR:E::jar::/usr/local/bin/jarwrapper:'
|
|
support for Java Applets:
|
|
':Applet:E::html::/usr/bin/appletviewer:'
|
|
or the following, if you want to be more selective:
|
|
':Applet:M::<!--applet::/usr/bin/appletviewer:'
|
|
|
|
Of course you have to fix the path names. The path/file names given in this
|
|
document match the Debian 2.1 system. (i.e. jdk installed in /usr,
|
|
custom wrappers from this document in /usr/local)
|
|
|
|
Note, that for the more selective applet support you have to modify
|
|
existing html-files to contain <!--applet--> in the first line
|
|
('<' has to be the first character!) to let this work!
|
|
|
|
For the compiled Java programs you need a wrapper script like the
|
|
following (this is because Java is broken in case of the filename
|
|
handling), again fix the path names, both in the script and in the
|
|
above given configuration string.
|
|
|
|
You, too, need the little program after the script. Compile like
|
|
gcc -O2 -o javaclassname javaclassname.c
|
|
and stick it to /usr/local/bin.
|
|
|
|
Both the javawrapper shellscript and the javaclassname program
|
|
were supplied by Colin J. Watson <cjw44@cam.ac.uk>.
|
|
|
|
====================== Cut here ===================
|
|
#!/bin/bash
|
|
# /usr/local/bin/javawrapper - the wrapper for binfmt_misc/java
|
|
|
|
if [ -z "$1" ]; then
|
|
exec 1>&2
|
|
echo Usage: $0 class-file
|
|
exit 1
|
|
fi
|
|
|
|
CLASS=$1
|
|
FQCLASS=`/usr/local/bin/javaclassname $1`
|
|
FQCLASSN=`echo $FQCLASS | sed -e 's/^.*\.\([^.]*\)$/\1/'`
|
|
FQCLASSP=`echo $FQCLASS | sed -e 's-\.-/-g' -e 's-^[^/]*$--' -e 's-/[^/]*$--'`
|
|
|
|
# for example:
|
|
# CLASS=Test.class
|
|
# FQCLASS=foo.bar.Test
|
|
# FQCLASSN=Test
|
|
# FQCLASSP=foo/bar
|
|
|
|
unset CLASSBASE
|
|
|
|
declare -i LINKLEVEL=0
|
|
|
|
while :; do
|
|
if [ "`basename $CLASS .class`" == "$FQCLASSN" ]; then
|
|
# See if this directory works straight off
|
|
cd -L `dirname $CLASS`
|
|
CLASSDIR=$PWD
|
|
cd $OLDPWD
|
|
if echo $CLASSDIR | grep -q "$FQCLASSP$"; then
|
|
CLASSBASE=`echo $CLASSDIR | sed -e "s.$FQCLASSP$.."`
|
|
break;
|
|
fi
|
|
# Try dereferencing the directory name
|
|
cd -P `dirname $CLASS`
|
|
CLASSDIR=$PWD
|
|
cd $OLDPWD
|
|
if echo $CLASSDIR | grep -q "$FQCLASSP$"; then
|
|
CLASSBASE=`echo $CLASSDIR | sed -e "s.$FQCLASSP$.."`
|
|
break;
|
|
fi
|
|
# If no other possible filename exists
|
|
if [ ! -L $CLASS ]; then
|
|
exec 1>&2
|
|
echo $0:
|
|
echo " $CLASS should be in a" \
|
|
"directory tree called $FQCLASSP"
|
|
exit 1
|
|
fi
|
|
fi
|
|
if [ ! -L $CLASS ]; then break; fi
|
|
# Go down one more level of symbolic links
|
|
let LINKLEVEL+=1
|
|
if [ $LINKLEVEL -gt 5 ]; then
|
|
exec 1>&2
|
|
echo $0:
|
|
echo " Too many symbolic links encountered"
|
|
exit 1
|
|
fi
|
|
CLASS=`ls --color=no -l $CLASS | sed -e 's/^.* \([^ ]*\)$/\1/'`
|
|
done
|
|
|
|
if [ -z "$CLASSBASE" ]; then
|
|
if [ -z "$FQCLASSP" ]; then
|
|
GOODNAME=$FQCLASSN.class
|
|
else
|
|
GOODNAME=$FQCLASSP/$FQCLASSN.class
|
|
fi
|
|
exec 1>&2
|
|
echo $0:
|
|
echo " $FQCLASS should be in a file called $GOODNAME"
|
|
exit 1
|
|
fi
|
|
|
|
if ! echo $CLASSPATH | grep -q "^\(.*:\)*$CLASSBASE\(:.*\)*"; then
|
|
# class is not in CLASSPATH, so prepend dir of class to CLASSPATH
|
|
if [ -z "${CLASSPATH}" ] ; then
|
|
export CLASSPATH=$CLASSBASE
|
|
else
|
|
export CLASSPATH=$CLASSBASE:$CLASSPATH
|
|
fi
|
|
fi
|
|
|
|
shift
|
|
/usr/bin/java $FQCLASS "$@"
|
|
====================== Cut here ===================
|
|
|
|
|
|
====================== Cut here ===================
|
|
/* javaclassname.c
|
|
*
|
|
* Extracts the class name from a Java class file; intended for use in a Java
|
|
* wrapper of the type supported by the binfmt_misc option in the Linux kernel.
|
|
*
|
|
* Copyright (C) 1999 Colin J. Watson <cjw44@cam.ac.uk>.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <stdarg.h>
|
|
#include <sys/types.h>
|
|
|
|
/* From Sun's Java VM Specification, as tag entries in the constant pool. */
|
|
|
|
#define CP_UTF8 1
|
|
#define CP_INTEGER 3
|
|
#define CP_FLOAT 4
|
|
#define CP_LONG 5
|
|
#define CP_DOUBLE 6
|
|
#define CP_CLASS 7
|
|
#define CP_STRING 8
|
|
#define CP_FIELDREF 9
|
|
#define CP_METHODREF 10
|
|
#define CP_INTERFACEMETHODREF 11
|
|
#define CP_NAMEANDTYPE 12
|
|
|
|
/* Define some commonly used error messages */
|
|
|
|
#define seek_error() error("%s: Cannot seek\n", program)
|
|
#define corrupt_error() error("%s: Class file corrupt\n", program)
|
|
#define eof_error() error("%s: Unexpected end of file\n", program)
|
|
#define utf8_error() error("%s: Only ASCII 1-255 supported\n", program);
|
|
|
|
char *program;
|
|
|
|
long *pool;
|
|
|
|
u_int8_t read_8(FILE *classfile);
|
|
u_int16_t read_16(FILE *classfile);
|
|
void skip_constant(FILE *classfile, u_int16_t *cur);
|
|
void error(const char *format, ...);
|
|
int main(int argc, char **argv);
|
|
|
|
/* Reads in an unsigned 8-bit integer. */
|
|
u_int8_t read_8(FILE *classfile)
|
|
{
|
|
int b = fgetc(classfile);
|
|
if(b == EOF)
|
|
eof_error();
|
|
return (u_int8_t)b;
|
|
}
|
|
|
|
/* Reads in an unsigned 16-bit integer. */
|
|
u_int16_t read_16(FILE *classfile)
|
|
{
|
|
int b1, b2;
|
|
b1 = fgetc(classfile);
|
|
if(b1 == EOF)
|
|
eof_error();
|
|
b2 = fgetc(classfile);
|
|
if(b2 == EOF)
|
|
eof_error();
|
|
return (u_int16_t)((b1 << 8) | b2);
|
|
}
|
|
|
|
/* Reads in a value from the constant pool. */
|
|
void skip_constant(FILE *classfile, u_int16_t *cur)
|
|
{
|
|
u_int16_t len;
|
|
int seekerr = 1;
|
|
pool[*cur] = ftell(classfile);
|
|
switch(read_8(classfile))
|
|
{
|
|
case CP_UTF8:
|
|
len = read_16(classfile);
|
|
seekerr = fseek(classfile, len, SEEK_CUR);
|
|
break;
|
|
case CP_CLASS:
|
|
case CP_STRING:
|
|
seekerr = fseek(classfile, 2, SEEK_CUR);
|
|
break;
|
|
case CP_INTEGER:
|
|
case CP_FLOAT:
|
|
case CP_FIELDREF:
|
|
case CP_METHODREF:
|
|
case CP_INTERFACEMETHODREF:
|
|
case CP_NAMEANDTYPE:
|
|
seekerr = fseek(classfile, 4, SEEK_CUR);
|
|
break;
|
|
case CP_LONG:
|
|
case CP_DOUBLE:
|
|
seekerr = fseek(classfile, 8, SEEK_CUR);
|
|
++(*cur);
|
|
break;
|
|
default:
|
|
corrupt_error();
|
|
}
|
|
if(seekerr)
|
|
seek_error();
|
|
}
|
|
|
|
void error(const char *format, ...)
|
|
{
|
|
va_list ap;
|
|
va_start(ap, format);
|
|
vfprintf(stderr, format, ap);
|
|
va_end(ap);
|
|
exit(1);
|
|
}
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
FILE *classfile;
|
|
u_int16_t cp_count, i, this_class, classinfo_ptr;
|
|
u_int8_t length;
|
|
|
|
program = argv[0];
|
|
|
|
if(!argv[1])
|
|
error("%s: Missing input file\n", program);
|
|
classfile = fopen(argv[1], "rb");
|
|
if(!classfile)
|
|
error("%s: Error opening %s\n", program, argv[1]);
|
|
|
|
if(fseek(classfile, 8, SEEK_SET)) /* skip magic and version numbers */
|
|
seek_error();
|
|
cp_count = read_16(classfile);
|
|
pool = calloc(cp_count, sizeof(long));
|
|
if(!pool)
|
|
error("%s: Out of memory for constant pool\n", program);
|
|
|
|
for(i = 1; i < cp_count; ++i)
|
|
skip_constant(classfile, &i);
|
|
if(fseek(classfile, 2, SEEK_CUR)) /* skip access flags */
|
|
seek_error();
|
|
|
|
this_class = read_16(classfile);
|
|
if(this_class < 1 || this_class >= cp_count)
|
|
corrupt_error();
|
|
if(!pool[this_class] || pool[this_class] == -1)
|
|
corrupt_error();
|
|
if(fseek(classfile, pool[this_class] + 1, SEEK_SET))
|
|
seek_error();
|
|
|
|
classinfo_ptr = read_16(classfile);
|
|
if(classinfo_ptr < 1 || classinfo_ptr >= cp_count)
|
|
corrupt_error();
|
|
if(!pool[classinfo_ptr] || pool[classinfo_ptr] == -1)
|
|
corrupt_error();
|
|
if(fseek(classfile, pool[classinfo_ptr] + 1, SEEK_SET))
|
|
seek_error();
|
|
|
|
length = read_16(classfile);
|
|
for(i = 0; i < length; ++i)
|
|
{
|
|
u_int8_t x = read_8(classfile);
|
|
if((x & 0x80) || !x)
|
|
{
|
|
if((x & 0xE0) == 0xC0)
|
|
{
|
|
u_int8_t y = read_8(classfile);
|
|
if((y & 0xC0) == 0x80)
|
|
{
|
|
int c = ((x & 0x1f) << 6) + (y & 0x3f);
|
|
if(c) putchar(c);
|
|
else utf8_error();
|
|
}
|
|
else utf8_error();
|
|
}
|
|
else utf8_error();
|
|
}
|
|
else if(x == '/') putchar('.');
|
|
else putchar(x);
|
|
}
|
|
putchar('\n');
|
|
free(pool);
|
|
fclose(classfile);
|
|
return 0;
|
|
}
|
|
====================== Cut here ===================
|
|
|
|
|
|
====================== Cut here ===================
|
|
#!/bin/bash
|
|
# /usr/local/java/bin/jarwrapper - the wrapper for binfmt_misc/jar
|
|
|
|
java -jar $1
|
|
====================== Cut here ===================
|
|
|
|
|
|
Now simply chmod +x the .class, .jar and/or .html files you want to execute.
|
|
To add a Java program to your path best put a symbolic link to the main
|
|
.class file into /usr/bin (or another place you like) omitting the .class
|
|
extension. The directory containing the original .class file will be
|
|
added to your CLASSPATH during execution.
|
|
|
|
|
|
To test your new setup, enter in the following simple Java app, and name
|
|
it "HelloWorld.java":
|
|
|
|
class HelloWorld {
|
|
public static void main(String args[]) {
|
|
System.out.println("Hello World!");
|
|
}
|
|
}
|
|
|
|
Now compile the application with:
|
|
javac HelloWorld.java
|
|
|
|
Set the executable permissions of the binary file, with:
|
|
chmod 755 HelloWorld.class
|
|
|
|
And then execute it:
|
|
./HelloWorld.class
|
|
|
|
|
|
To execute Java Jar files, simple chmod the *.jar files to include
|
|
the execution bit, then just do
|
|
./Application.jar
|
|
|
|
|
|
To execute Java Applets, simple chmod the *.html files to include
|
|
the execution bit, then just do
|
|
./Applet.html
|
|
|
|
|
|
originally by Brian A. Lantz, brian@lantz.com
|
|
heavily edited for binfmt_misc by Richard Günther
|
|
new scripts by Colin J. Watson <cjw44@cam.ac.uk>
|
|
added executable Jar file support by Kurt Huwig <kurt@iku-netz.de>
|
|
|