EM86: a Linux/x86 Emulator for Linux/Alpha
________________________________________________________________
EM86 0.9.1 README
April 4, 1997
This document describes the EM86 0.9.1 beta software release.
Contents
Introduction................................. 1
Feedback..................................... 2
Package Contents............................. 2
Installation................................. 5
Running EM86................................. 5
Application Notes............................ 6
Restrictions................................. 8
________________________________________________________________
Digital Equipment Corporation
Maynard, Massachusetts
________________________________________________________________
EM86 0.9.1 README
EM86 0.9.1 README
______________________ WARNING ______________________
This early version of EM86 for Linux/Alpha is a
developers' beta that we are releasing to the Linux
community for evaluation purposes and for software
verification. The current kit lacks numerous
features that are planned for the final product;
probably includes bugs; and has undergone little
performance tuning. Therefore, the correctness
and performance of this beta release in no way
represents the quality of the final product. We
also strongly recommend against using this beta in
any production environment.
_____________________________________________________
Introduction
You've bought a Linux/Alpha system and now you want to
run all the great software that's currently available only
for Linux/x86. EM86, a Linux/x86 emulator for Linux/Alpha,
makes this possible! Based on Digital's award-winning
FX!32 technology, EM86 allows Linux/x86 binaries to run on
Linux/Alpha without modification. So far, we have successfully
tested the following applications for compatibility with EM86:
Netscape Navigator Gold 3.01
Adobe Acrobat Reader 3.0
Applixware Version 4.2
Red Baron web browser 3.0
________________________________________________________________
(c) Digital Equipment Corporation 1997. All rights reserved.
Netscape Navigator Gold is a trademark of Netscape Communications
Corporation. Acrobat Reader is a trademark of Adobe Systems Incorporated.
Applixware is a trademark of Applix, Inc.
EM86 0.9.1 README 1
EM86 0.9.1 README
Introduction
We will test many more between now and the final product
release.
Feedback
We welcome suggestions, comments, and reports on your
experiences testing EM86 0.9.1. You can send email to us
at the following address:
[email protected]
Package Contents
The developers's beta release of EM86 is available from
the following ftp site:
ftp.digital.com:/pub/DEC/Linux-Alpha/em86
The EM86 distribution includes the following archive
files:
__________________________________________________________
File__________________Contents____________________________
em86-bin.tar.gz The EM86 binary and all auxiliary
file binaries.
em86-libs.tar.gz A collection of Linux/x86 shared
libraries for running dynamically-
linked ELF binaries.
em86-src.tar.gz Sources for EM86 and related
programs.
kernel-patches.tar.gz Kernel patches needed to enable
______________________certain_EM86_features.______________
2 EM86 0.9.1 README
EM86 0.9.1 README
Package Contents
The following table describes the contents of each archive:
__________________________________________________________
Archive_______________Contents____________________________
em86-bin.tar.gz This archive contains the following
files:
o /usr/bin/em86
The emulator itself.
o /usr/bin/ldconfig86
A version of ldconfig for
Linux/x86 ELF binaries that works
with the modified library path
that EM86 uses.
o /usr/bin/ldd86
A version of ldd for Linux/x86
ELF binaries that works with the
modified library path that EM86
uses.
o /usr/x86/linux486.idx
An auxiliary data file needed by
EM86.
o /usr/x86/lib/ld-linux.so.1.7.1.4.em86
A special version of the
Linux/x86 ELF shared library
loader that works with EM86.
em86-libs.tar.gz This archive contains a snapshot of
Linux/x86 shared libraries from the
Red Hat 4.0 distribution.
EM86 0.9.1 README 3
EM86 0.9.1 README
Package Contents
__________________________________________________________
Archive_______________Contents____________________________
em86-src.tar.gz This is the source for EM86. Note
that the source code is provided
for the runtime system but NOT for
the x86 execution engine. The x86
execution engine is proprietary code
of Digital Equipment Corporation
and the source is not available.
The source archive contains a binary
object library for the execution
engine in FX_EM486/libem486.a.
kernel-patches.tar.gz This file contains kernel patches
required to enable certain features
of EM86. There are two files in this
archive:
o em86-patch
This patch is required to
implement transparent execution
of Linux/x86 binaries. With this
patch, you can simply invoke a
Linux/x86 binary as you would
any other program and the kernel
automatically recognizes it and
invokes EM86. Without this patch,
the only way to run a Linux/x86
binary is to invoke EM86
explicitly.
o traparg-patch-2.0
This patch for 2.0.x kernels
passes additional information to the
signal handler on memory faults.
This is required in order to
implement automatic stack growth.
If you do not apply this patch,
you may have problems if your
program uses a large stack.
__________________________________________________________
4 EM86 0.9.1 README
EM86 0.9.1 README
Installation
Installation
To install EM86, you need at least the em86-bin.tar.gz
archive. To install this archive, su to root and unpack
this archive from the root directory, for example:
$ su
Password:
# cd /
# tar xvzpf /home/bob/em86-bin.tar.gz
This setup enables you to run statically-linked Linux/x86
binaries by explicitly invoking EM86, for example:
$ /usr/bin/em86 hello.x86
hello, world
$
To run most significant Linux/x86 packages, you need
Linux/x86 shared libraries. To avoid conflicts with the
existing shared libraries on the Linux/Alpha system, EM86
looks for shared libraries in the /usr/x86 tree.
The easiest way to install shared libraries is to install
the em86-libs.tar.gz file as shown above for the archive
em86-bin.tar.gz. However, if you have a slow network
connection and a Linux/x86 system is available, you can
copy the shared libraries to the Linux/Alpha system as
follows:
__________________________________________________________
Copy_from_x86_system_______To_this_Alpha_system_tree______
/lib/lib*.so* /usr/x86/lib
/usr/lib/lib*.so* /usr/x86/usr/lib
/usr/X11R6/lib/lib*.so*____/usr/x86/usr/X11R6/lib_________
Similarly, install any Linux/x86 shared libraries you need
subsequently under the /usr/x86 hierarchy.
DO NOT under any circumstances replace
/usr/x86/lib/ld-linux.so.*, which is a special version
built to operate with EM86. Replacing it with one not
so modified can cause emulated programs not to work.
EM86 0.9.1 README 5
EM86 0.9.1 README
Installation
Finally, for the smoothest operation of EM86, we strongly
suggest that you apply the kernel patches described above
(em86-patch and traparg-patch-2.0) and rebuild your
kernel. The em86-patch adds a new configuration option
(support for Linux/x86 ELF binaries). Be sure to enable
this option!
Running EM86
Once you have installed EM86 and applied the kernel patch
em86-patch, Linux/Alpha invokes EM86 automatically when
you invoke a Linux/x86 application.
If you have not applied the patch, you can invoke
EM86 to run a Linux/x86 executable with the following command:
$ em86 x86_executable_name
See the man page for details on the EM86 operating environment.
Application Notes
EM86 has been tested on numerous test cases and small
applications (xtetris, for example). In addition, three
major packages have been verified to run to varying
degrees under EM86. Following are notes on each package.
__________________________________________________________
Application___________Notes_______________________________
Netscape Navigator Install Netscape Navigator Gold
Gold 3.01 as per the supplied installation
instructions.
_____________ WARNING_____________
DO NOT under ANY circumstances enable
Java or JavaScript until further notice.
Attempting to use these WILL crash your
browser. While this is a known problem
even under Linux/x86, none of the suggested
workarounds improved the situation. We are
currently investigating this problem.
__________________________________
If Netscape has trouble locating
Internet hosts, but you can ping
these hosts from the command line,
try installing an /etc/nsswitch.conf
file.
6 EM86 0.9.1 README
EM86 0.9.1 README
Application Notes
__________________________________________________________
Application___________Notes_______________________________
Adobe Acrobat Reader Use the supplied install procedure
3.0 to install Acrobat Reader. With
the em86-patch applied to your
kernel, this application should
run normally. Otherwise, you will
need to modify the script
/usr/local/Acrobat3/bin/acroread
to use EM86 to invoke the acroread
binary.
Applixware 4.2 Because Applixware uses rpm for
installation, you must override
the architecture check. (rpm does
not normally allow you to install
the binaries for one architecture
onto a machine of a different
architecture). To override, copy
the install script from the CD to
a writable location, then edit the
script to supply the "-ignorearch"
flag to rpm. Since Applixware has
binaries that invoke other binaries,
you need to apply the em86-patch
to the kernel for it to run. Since
Applixware pushes lots of data on
the stack, you also need to apply
______________________the_traparg-patch_to_the_kernel.____
EM86 0.9.1 README 7
EM86 0.9.1 README
Restrictions
Restrictions
The EM86 restrictions are as follows:
o EM86 emulates user-mode code only.
o EM86 cannot run programs that access virtual memory
above the address 78000000.
o EM86 does not now, nor will in the future, support the
following system calls: setup, break, ptrace, stty,
gtty, prof, acct, phys, lock, mpx, ulimit, profil,
ioperm, iopl, idle, mx86, modify-Ldt, create_module,
init_module, delete_module, get_kernel_syms, bdflush,
afs_syscall, and sysctl.
o EM86 0.9.1 does not support the following system
calls that will be supported in future releases: mount,
umount, uselib, old_readdir, sysinfo, ipc sigreturn,
clone, adjtimex, quotactl, sysfs, flock, msync, mlock,
munlock, mlockall, munlockall, sched_setparam,
sched_getparam, sched_setscheduler, sched_getscheduler,
sched_yield, sched_get_priority_max, sched_get_priority_min,
sched_rr_get_interval, nanosleep, and mremap.
8 EM86 0.9.1 README
