xref: /external/qemu/INSTALL

This package contains the sources to the Android emulator program.

Supported Development Platforms:
--------------------------------

The Android emulator can be built on the following platforms:

    - Linux 32-bits
    - Linux 64-bits (*only* generates 32-bit emulator binary)
    - Darwin x86
    - Darwin ppc  (experimental only)
    - Windows x86  (through Cygwin only)

Note that development on 64-bit versions of Darwin and Windows is
not supported. The 32-bit emulator binary should run normally on
these platforms though.

The Windows emulator binary is built using the -no-cygwin option
and thus doesn't depend on CYGWIN.DLL being installed on your system.

It is possible to hack the android-configure.sh script to build
a 64-bit emulator binary on Linux. Unfortunately the resulting
program will crash pretty soon during emulation. This problem is
due to the way the emulator works and cannot be easily fixed at
the moment.

Supported Compilers:
--------------------

The Android emulator is a heavy fork of QEMU 0.8.2, and as such,
can only be built properly with a small number of compilers. Moreover,
which compiler can be used depends on your platform.

The following table sums up the compilers that are *known* to produce
correct output:

  Linux x86:              gcc-3.4.6
  Linux x86 and x86_64:   gcc-4.2.3
  Darwin x86:             gcc-4.0.1 (build 5341)
  Darwin ppc:             gcc-3.3   (build 1819)

Use any other compiler at your own risks ! A 'bad binary' usually
results in the VM crashing either immediately or after a few seconds.

Note that on Darwin, the *build* number of your compiler *is* important.
Some builds of gcc-4.0.1 are known to generate bad binaries on Darwin x86,
so your own fails to build an executable that works correctly.
You can find the sources to the required gcc here:


We distribute a file named distrib/build_gcc_qemu_darwin.sh which can be
used as a replacement for the Apple-provided build_gcc.sh that comes with
their gcc distribution.


Building the emulator with the Android build system:
----------------------------------------------------

Ensure that you have properly configured your build by running the
envsetup.sh script and using the appropriate 'lunch' command.

Then type: 

     m emulator

This will rebuild the emulator and place it in an adequate location.
Simply type 'emulator' to start it with the currently built system
image.


Building the emulator without the Android build system:
-------------------------------------------------------

You can also build the emulator as a stand-alone program, by following
these simple steps:

  1/ First, build Android's patched libSDL as a static library,
     this can be done as:

        cd $TOP/external/qemu/distrib/sdl-1.2.15
        ./android-configure --prefix=<PATH>
        make
        make install

    Where $TOP is the path of your open-source Android source tree, and
    where <PATH> is any path of your chosing where the library will
    be copied to by the 'make install' command. For example, you
    can use $HOME/android-sdl

  2/ Configure the emulator with android-configure.sh, as in:

        cd $TOP/external/qemu
        ./android-configure.sh --sdl-config=<PATH>/bin/sdl-config
        make

     Where <PATH> is the same path you used with the --prefix option
     when building the SDL library

The emulator binary is located into objs/emulator, you can strip it and
copy it to any location of your choosing.


Creating an emulator source distribution package:
-------------------------------------------------

We provide a script to build a tar.gz package file that contains all the
sources required to rebuild the emulator (i.e. it includes the patched SDL
sources as well) plus a handy script to automate the rebuild.

Simply invoke:

    cd $TOP/tools/qemu
    distrib/make-distrib.sh

This script will create a tar.gz file under /tmp/android-package and will
print its location when it completes.

To rebuild the corresponding emulator, un-tar-gz the package, and run
the 'rebuild.sh' script.