Commit 503c5bf9 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab

Documentation/java.txt: convert to ReST markup

- Fix document title;
- use quote blocks where needed;
- use monotonic fonts for config options and file names;
- adjust whitespaces and blank lines;
- add it to the user's book.
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 9cdda3d2
Java(tm) Binary Kernel Support for Linux v1.03 Java(tm) Binary Kernel Support for Linux v1.03
---------------------------------------------- ----------------------------------------------
Linux beats them ALL! While all other OS's are TALKING about direct Linux beats them ALL! While all other OS's are TALKING about direct
support of Java Binaries in the OS, Linux is doing it! support of Java Binaries in the OS, Linux is doing it!
...@@ -19,70 +19,80 @@ other program after you have done the following: ...@@ -19,70 +19,80 @@ other program after you have done the following:
as the application itself). as the application itself).
2) You have to compile BINFMT_MISC either as a module or into 2) You have to compile BINFMT_MISC either as a module or into
the kernel (CONFIG_BINFMT_MISC) and set it up properly. the kernel (``CONFIG_BINFMT_MISC``) and set it up properly.
If you choose to compile it as a module, you will have If you choose to compile it as a module, you will have
to insert it manually with modprobe/insmod, as kmod to insert it manually with modprobe/insmod, as kmod
cannot easily be supported with binfmt_misc. cannot easily be supported with binfmt_misc.
Read the file 'binfmt_misc.txt' in this directory to know Read the file 'binfmt_misc.txt' in this directory to know
more about the configuration process. more about the configuration process.
3) Add the following configuration items to binfmt_misc 3) Add the following configuration items to binfmt_misc
(you should really have read binfmt_misc.txt now): (you should really have read ``binfmt_misc.txt`` now):
support for Java applications: support for Java applications::
':Java:M::\xca\xfe\xba\xbe::/usr/local/bin/javawrapper:' ':Java:M::\xca\xfe\xba\xbe::/usr/local/bin/javawrapper:'
support for executable Jar files:
support for executable Jar files::
':ExecutableJAR:E::jar::/usr/local/bin/jarwrapper:' ':ExecutableJAR:E::jar::/usr/local/bin/jarwrapper:'
support for Java Applets:
support for Java Applets::
':Applet:E::html::/usr/bin/appletviewer:' ':Applet:E::html::/usr/bin/appletviewer:'
or the following, if you want to be more selective:
or the following, if you want to be more selective::
':Applet:M::<!--applet::/usr/bin/appletviewer:' ':Applet:M::<!--applet::/usr/bin/appletviewer:'
Of course you have to fix the path names. The path/file names given in this 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, document match the Debian 2.1 system. (i.e. jdk installed in ``/usr``,
custom wrappers from this document in /usr/local) custom wrappers from this document in ``/usr/local``)
Note, that for the more selective applet support you have to modify Note, that for the more selective applet support you have to modify
existing html-files to contain <!--applet--> in the first line existing html-files to contain ``<!--applet-->`` in the first line
('<' has to be the first character!) to let this work! (``<`` has to be the first character!) to let this work!
For the compiled Java programs you need a wrapper script like the For the compiled Java programs you need a wrapper script like the
following (this is because Java is broken in case of the filename 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 handling), again fix the path names, both in the script and in the
above given configuration string. above given configuration string.
You, too, need the little program after the script. Compile like You, too, need the little program after the script. Compile like::
gcc -O2 -o javaclassname javaclassname.c
and stick it to /usr/local/bin. gcc -O2 -o javaclassname javaclassname.c
and stick it to ``/usr/local/bin``.
Both the javawrapper shellscript and the javaclassname program Both the javawrapper shellscript and the javaclassname program
were supplied by Colin J. Watson <cjw44@cam.ac.uk>. were supplied by Colin J. Watson <cjw44@cam.ac.uk>.
====================== Cut here =================== Javawrapper shell script::
#!/bin/bash
# /usr/local/bin/javawrapper - the wrapper for binfmt_misc/java #!/bin/bash
# /usr/local/bin/javawrapper - the wrapper for binfmt_misc/java
if [ -z "$1" ]; then if [ -z "$1" ]; then
exec 1>&2 exec 1>&2
echo Usage: $0 class-file echo Usage: $0 class-file
exit 1 exit 1
fi fi
CLASS=$1 CLASS=$1
FQCLASS=`/usr/local/bin/javaclassname $1` FQCLASS=`/usr/local/bin/javaclassname $1`
FQCLASSN=`echo $FQCLASS | sed -e 's/^.*\.\([^.]*\)$/\1/'` FQCLASSN=`echo $FQCLASS | sed -e 's/^.*\.\([^.]*\)$/\1/'`
FQCLASSP=`echo $FQCLASS | sed -e 's-\.-/-g' -e 's-^[^/]*$--' -e 's-/[^/]*$--'` FQCLASSP=`echo $FQCLASS | sed -e 's-\.-/-g' -e 's-^[^/]*$--' -e 's-/[^/]*$--'`
# for example: # for example:
# CLASS=Test.class # CLASS=Test.class
# FQCLASS=foo.bar.Test # FQCLASS=foo.bar.Test
# FQCLASSN=Test # FQCLASSN=Test
# FQCLASSP=foo/bar # FQCLASSP=foo/bar
unset CLASSBASE unset CLASSBASE
declare -i LINKLEVEL=0 declare -i LINKLEVEL=0
while :; do while :; do
if [ "`basename $CLASS .class`" == "$FQCLASSN" ]; then if [ "`basename $CLASS .class`" == "$FQCLASSN" ]; then
# See if this directory works straight off # See if this directory works straight off
cd -L `dirname $CLASS` cd -L `dirname $CLASS`
...@@ -119,9 +129,9 @@ while :; do ...@@ -119,9 +129,9 @@ while :; do
exit 1 exit 1
fi fi
CLASS=`ls --color=no -l $CLASS | sed -e 's/^.* \([^ ]*\)$/\1/'` CLASS=`ls --color=no -l $CLASS | sed -e 's/^.* \([^ ]*\)$/\1/'`
done done
if [ -z "$CLASSBASE" ]; then if [ -z "$CLASSBASE" ]; then
if [ -z "$FQCLASSP" ]; then if [ -z "$FQCLASSP" ]; then
GOODNAME=$FQCLASSN.class GOODNAME=$FQCLASSN.class
else else
...@@ -131,24 +141,23 @@ if [ -z "$CLASSBASE" ]; then ...@@ -131,24 +141,23 @@ if [ -z "$CLASSBASE" ]; then
echo $0: echo $0:
echo " $FQCLASS should be in a file called $GOODNAME" echo " $FQCLASS should be in a file called $GOODNAME"
exit 1 exit 1
fi fi
if ! echo $CLASSPATH | grep -q "^\(.*:\)*$CLASSBASE\(:.*\)*"; then if ! echo $CLASSPATH | grep -q "^\(.*:\)*$CLASSBASE\(:.*\)*"; then
# class is not in CLASSPATH, so prepend dir of class to CLASSPATH # class is not in CLASSPATH, so prepend dir of class to CLASSPATH
if [ -z "${CLASSPATH}" ] ; then if [ -z "${CLASSPATH}" ] ; then
export CLASSPATH=$CLASSBASE export CLASSPATH=$CLASSBASE
else else
export CLASSPATH=$CLASSBASE:$CLASSPATH export CLASSPATH=$CLASSBASE:$CLASSPATH
fi fi
fi fi
shift shift
/usr/bin/java $FQCLASS "$@" /usr/bin/java $FQCLASS "$@"
====================== Cut here ===================
javaclassname.c::
====================== Cut here =================== /* javaclassname.c
/* javaclassname.c
* *
* Extracts the class name from a Java class file; intended for use in a Java * 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. * wrapper of the type supported by the binfmt_misc option in the Linux kernel.
...@@ -170,57 +179,57 @@ shift ...@@ -170,57 +179,57 @@ shift
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/ */
#include <stdlib.h> #include <stdlib.h>
#include <stdio.h> #include <stdio.h>
#include <stdarg.h> #include <stdarg.h>
#include <sys/types.h> #include <sys/types.h>
/* From Sun's Java VM Specification, as tag entries in the constant pool. */ /* From Sun's Java VM Specification, as tag entries in the constant pool. */
#define CP_UTF8 1 #define CP_UTF8 1
#define CP_INTEGER 3 #define CP_INTEGER 3
#define CP_FLOAT 4 #define CP_FLOAT 4
#define CP_LONG 5 #define CP_LONG 5
#define CP_DOUBLE 6 #define CP_DOUBLE 6
#define CP_CLASS 7 #define CP_CLASS 7
#define CP_STRING 8 #define CP_STRING 8
#define CP_FIELDREF 9 #define CP_FIELDREF 9
#define CP_METHODREF 10 #define CP_METHODREF 10
#define CP_INTERFACEMETHODREF 11 #define CP_INTERFACEMETHODREF 11
#define CP_NAMEANDTYPE 12 #define CP_NAMEANDTYPE 12
#define CP_METHODHANDLE 15 #define CP_METHODHANDLE 15
#define CP_METHODTYPE 16 #define CP_METHODTYPE 16
#define CP_INVOKEDYNAMIC 18 #define CP_INVOKEDYNAMIC 18
/* Define some commonly used error messages */ /* Define some commonly used error messages */
#define seek_error() error("%s: Cannot seek\n", program) #define seek_error() error("%s: Cannot seek\n", program)
#define corrupt_error() error("%s: Class file corrupt\n", program) #define corrupt_error() error("%s: Class file corrupt\n", program)
#define eof_error() error("%s: Unexpected end of file\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); #define utf8_error() error("%s: Only ASCII 1-255 supported\n", program);
char *program; char *program;
long *pool; long *pool;
u_int8_t read_8(FILE *classfile); u_int8_t read_8(FILE *classfile);
u_int16_t read_16(FILE *classfile); u_int16_t read_16(FILE *classfile);
void skip_constant(FILE *classfile, u_int16_t *cur); void skip_constant(FILE *classfile, u_int16_t *cur);
void error(const char *format, ...); void error(const char *format, ...);
int main(int argc, char **argv); int main(int argc, char **argv);
/* Reads in an unsigned 8-bit integer. */ /* Reads in an unsigned 8-bit integer. */
u_int8_t read_8(FILE *classfile) u_int8_t read_8(FILE *classfile)
{ {
int b = fgetc(classfile); int b = fgetc(classfile);
if(b == EOF) if(b == EOF)
eof_error(); eof_error();
return (u_int8_t)b; return (u_int8_t)b;
} }
/* Reads in an unsigned 16-bit integer. */ /* Reads in an unsigned 16-bit integer. */
u_int16_t read_16(FILE *classfile) u_int16_t read_16(FILE *classfile)
{ {
int b1, b2; int b1, b2;
b1 = fgetc(classfile); b1 = fgetc(classfile);
if(b1 == EOF) if(b1 == EOF)
...@@ -229,11 +238,11 @@ u_int16_t read_16(FILE *classfile) ...@@ -229,11 +238,11 @@ u_int16_t read_16(FILE *classfile)
if(b2 == EOF) if(b2 == EOF)
eof_error(); eof_error();
return (u_int16_t)((b1 << 8) | b2); return (u_int16_t)((b1 << 8) | b2);
} }
/* Reads in a value from the constant pool. */ /* Reads in a value from the constant pool. */
void skip_constant(FILE *classfile, u_int16_t *cur) void skip_constant(FILE *classfile, u_int16_t *cur)
{ {
u_int16_t len; u_int16_t len;
int seekerr = 1; int seekerr = 1;
pool[*cur] = ftell(classfile); pool[*cur] = ftell(classfile);
...@@ -270,19 +279,19 @@ void skip_constant(FILE *classfile, u_int16_t *cur) ...@@ -270,19 +279,19 @@ void skip_constant(FILE *classfile, u_int16_t *cur)
} }
if(seekerr) if(seekerr)
seek_error(); seek_error();
} }
void error(const char *format, ...) void error(const char *format, ...)
{ {
va_list ap; va_list ap;
va_start(ap, format); va_start(ap, format);
vfprintf(stderr, format, ap); vfprintf(stderr, format, ap);
va_end(ap); va_end(ap);
exit(1); exit(1);
} }
int main(int argc, char **argv) int main(int argc, char **argv)
{ {
FILE *classfile; FILE *classfile;
u_int16_t cp_count, i, this_class, classinfo_ptr; u_int16_t cp_count, i, this_class, classinfo_ptr;
u_int8_t length; u_int8_t length;
...@@ -349,19 +358,19 @@ int main(int argc, char **argv) ...@@ -349,19 +358,19 @@ int main(int argc, char **argv)
free(pool); free(pool);
fclose(classfile); fclose(classfile);
return 0; return 0;
} }
====================== Cut here ===================
jarwrapper::
====================== Cut here =================== #!/bin/bash
#!/bin/bash # /usr/local/java/bin/jarwrapper - the wrapper for binfmt_misc/jar
# /usr/local/java/bin/jarwrapper - the wrapper for binfmt_misc/jar
java -jar $1 java -jar $1
====================== Cut here ===================
Now simply chmod +x the .class, .jar and/or .html files you want to execute. 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 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 .class file into /usr/bin (or another place you like) omitting the .class
extension. The directory containing the original .class file will be extension. The directory containing the original .class file will be
...@@ -369,7 +378,7 @@ added to your CLASSPATH during execution. ...@@ -369,7 +378,7 @@ added to your CLASSPATH during execution.
To test your new setup, enter in the following simple Java app, and name To test your new setup, enter in the following simple Java app, and name
it "HelloWorld.java": it "HelloWorld.java"::
class HelloWorld { class HelloWorld {
public static void main(String args[]) { public static void main(String args[]) {
...@@ -377,23 +386,28 @@ it "HelloWorld.java": ...@@ -377,23 +386,28 @@ it "HelloWorld.java":
} }
} }
Now compile the application with: Now compile the application with::
javac HelloWorld.java javac HelloWorld.java
Set the executable permissions of the binary file, with: Set the executable permissions of the binary file, with::
chmod 755 HelloWorld.class chmod 755 HelloWorld.class
And then execute it: And then execute it::
./HelloWorld.class ./HelloWorld.class
To execute Java Jar files, simple chmod the *.jar files to include To execute Java Jar files, simple chmod the ``*.jar`` files to include
the execution bit, then just do the execution bit, then just do::
./Application.jar ./Application.jar
To execute Java Applets, simple chmod the *.html files to include To execute Java Applets, simple chmod the ``*.html`` files to include
the execution bit, then just do the execution bit, then just do::
./Applet.html ./Applet.html
......
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