
            =============================================
            Getting started with 'base-hw' on the Muen SK
            =============================================


                            The Muen Team

Abstract
########

This is a short tutorial that depicts a handy way to get a Genode image, built
with 'base-hw', started as subject on the Muen Separation Kernel (SK)
[https://muen.sk].

Tutorial
########

For information on how to download, build and prove the Muen SK refer to the
project website. In summary: install the Ada/SPARK tool-chain and all required
distribution packages. Also ensure that you have installed the Genode tool-chain
that is available at:

:[https://genode.org/download/tool-chain]:
  Genode tool-chain

To automatically download the Muen kernel and integrate it with Genode, issue
the following commands:

! cd <genode_dir>
! ./tool/ports/prepare_port muen

The next step is to create a build directory prepared for compiling Genode for
Muen. Use the create_builddir tool for this task:

! ./tool/create_builddir muen

You can customize Muen system by changing the --image-muen RUN_OPT parameters
in the 'build.conf' file in the build directory under build/etc.

The file contains explanatory comments above each configuration variable, which
are all set to their default values.

Muen systems are built for a specific hardware platform and by default the
system is built for the Lenovo T430s. All currently supported platforms have a
corresponding hardware specification which can be found in the Muen project
directory under 'policy/platform'. Note that the Muen project directory can be
found at '<genode_dir>/contrib/muen-*/src/kernel/muen'.

To get a list of all currently supported platforms issue the following command:

! ls contrib/muen-*/src/kernel/muen/policy/platform/ | grep -v common

Set the '--image-muen-hardware' parameter to point to the hardware
configuration file of your intended hardware platform. Note that the specified
paths for both '--image-muen-hardware' and '--image-muen-system' must be either
relative to the Muen policy directory (e.g. 'platform/lenovo-t430s.xml' or
'xml/genode-base_hw_simple.xml') or absolute paths. Also change the
other parameters to match your environment.

If no hardware configuration for your specific hardware is available, refer to
the README of the 'mugenhwcfg' tool
[https://git.codelabs.ch/?p=muen/mugenhwcfg.git] for instructions on how to
generate a new configuration.

You can now change to the created build directory and compile a Genode system:

! cd build/muen/
! make run/log

Once the build is done, the Muen system which contains the Genode scenario is
available as a Multiboot binary image under 'var/run/log/image.bin'. If an
error occurs during the Muen build process check the log file located at
'kernel/build.log'.

Automated hardware deployment
#############################

For automated deployment and execution on real hardware, the iPXE and AMT run
mechanisms provided by the Genode build system can be used. The modules are
controlled by the RUN_OPT variable specified in the 'etc/build.conf' file.  An
example configuration for executing a Muen/Genode system on a real x86 machine
using AMT for resetting the target system and capturing the log output while
loading the Muen system image via iPXE:

!RUN_OPT += --include power_on/amt
!RUN_OPT += --power-on-amt-host 192.168.254.2
!RUN_OPT += --power-on-amt-password 'foo!'
!RUN_OPT += --include load/ipxe
!RUN_OPT += --load-ipxe-base-dir /srv/www
!RUN_OPT += --load-ipxe-boot-dir boot
!RUN_OPT += --include log/amt
!RUN_OPT += --log-amt-host 192.168.254.2
!RUN_OPT += --log-amt-password 'foo!'

The target machine is expected to request the following iPXE configuration:
http://${HOST_URL}/${ipxe-boot-dir}/boot.cfg. This can be achieved by building
iPXE with the following embedded script:

! #!ipxe
! dhcp
! chain http://${HOST_URL}/${ipxe-boot-dir}/boot.cfg

For additional information on iPXE and embedded scripts refer to the iPXE website
at [http://ipxe.org/howto/chainloading#breaking_the_loop_with_an_embedded_script].

The deployment host must serve the Genode system image via http. In the above
example the root directory of the webserver is '/srv/www'. Note that the
webserver must support ranged requests as otherwise iPXE will not load (large)
system image files correctly.

Integration of Muen with Genode
###############################

Instead of letting the Genode build system compile and assemble the complete
Muen system, you can let it only build a specific Genode base-hw run scenario
and then do the integration yourself. This will for example allow you to run a
simple script like run/log on Muen in the Bochs x86 emulator
[http://bochs.sf.net], removing the requirement for having access to supported
hardware.

As a first step acquire the Muen sources by executing the following commands:

! git clone https://git.codelabs.ch/git/muen.git
! cd muen
! git submodule update --init tools/mugenschedcfg
! make SYSTEM=xml/genode-base_hw_simple.xml COMPONENTS="libdebuglog libmutime dbgserver sm time" emulate

This will build a Muen SK system and start it using the Bochs emulator. You
should get the following error:

! mupack: File '<muen_workdir>/pack/../policy/obj/base_hw' referenced by
!         physical memory region 'base_hw|bin' not found

This means that the Muen packer tool was unable to find the component binary
'base_hw', which is expected since it has not yet been compiled.

Now it is time to build the Genode 'base-hw' image for Muen. To tell the Genode
build system that the Muen system integration is performed externally by
changing the --image-muen-external-build parameter in the 'etc/build.conf' file
within your build Genode directory like so:

! RUN_OPT += --image-muen-external-build 1

After this change you can build the Genode 'base-hw' image and export it to the
Muen working directory using the following command:

! objcopy -O binary var/run/log/image.elf <muen_workdir>/policy/obj/base_hw

Change back to the Muen working directory to package the system image and
restart emulation:

! cd <muen_workdir>
! make SYSTEM=xml/genode-base_hw_simple.xml COMPONENTS="libdebuglog libmutime dbgserver sm time" emulate

The serial output of the system is written to the
'<muen_workdir>/emulate/serial.out' file. You should see the following line:

! [init -> test-log] Test done.

This indicates the successful execution of the Genode 'run/log' scenario as
Muen subject on Bochs.
