Simics includes many customizable ready-to-run configurations. Because
checkpoint files are by definition static, these example configurations
are not checkpoint-based, but rather built on components and
scripts to generate a working simulated machine.
The example configurations are located in separate directories for each system
architecture:
[simics]\targets\architecture
<machine>-common.simics- Scripts that define a complete simulated machine, i.e., both hardware and
software, that can be run by Simics directly. Each
common script
uses the corresponding -system.include script to define the hardware, and the
-setup.include script for software configuration. The
-common.simics scripts may add additional hardware in some cases.
These are the files you want to use to start the standard example machines
in this directory.
<machine> in the script name is either a Linux machine name, or a some
other name that defines the hardware/software combination.
<machine>-<feature>-common.simics- A script that extends the
-common.simics script with a new
feature. Many minor features, such as the processor frequency, can be
controlled using parameters to the common script, but features
that are mutually exclusive are added as separate scripts. Typical examples
are scripts that add different diff-files to the same disk image in the system
setup. <architecture-variant>-system.include- A script that defines the hardware of a machine. This script can be shared
by several simulated machines that are based on the same hardware. The hardware
setup is typically configurable using some standard parameters.
<machine>-setup.include- A script that defines the software and possibly configures the machine to
run the selected software, for example setting boot path, and scripting
automatic login.
The example configurations are designed to work with the disk images
distributed with Simics. The machines are described in the Target
Guide corresponding to each architecture.
Several machines may be defined for a given architecture, and thus the
corresponding architecture directory will contain several
-common.simics scripts.
There are several ways to customize the examples provided with Simics. They
are listed below ordered by how simple they are to use.
- Parameters
- The machine scripts distributed with Simics can be
modified by setting parameters (CLI variables) before the script is actually
run. This is the easiest way to change the default configuration. Parameters
can typically be used to change properties such as the amount of memory, the
number of processors and the primary MAC address. The available parameters are
listed in each Target Guide.
Setting parameters before the script is run can be done in two fashions:
-
Use the startup flag
-e. The flag must be repeated for
each parameter to set.
An example on Windows:
$ simics.bat -e '$freq_mhz = 2000' -e '$host_name = "target0"'
targets/qsp-x86/firststeps.simics
An example on Linux:
$ ./simics -e '$freq_mhz = 2000' -e '$host_name = "target0"'
targets/qsp-x86/firststeps.simics
-
Launch Simics without any script, set the parameters at CLI, and
run the CLI command run-command-file.
An example identical to the one above:
$ simics.bat
simics> $freq_mhz = 2000
simics> $host_name = "target0"
simics> run-command-file targets/qsp-x86/firststeps.simics
- Scripts
- A simulated machine is defined by several scripts, as
described above. By replacing the
-common.simics file with a user
defined script, the system can be configured more in detail while keeping the
machine definition provided by the -system.include file. Similarly
the -setup.include can be replaced to configure different software
on the same machine. - Components
- Components represents real hardware items such as PCI
cards, motherboards, and disks. Using components to configure a machine
provides freedom to set up the simulated machine in any way that is supported
by the architecture. The
-system.include files use components to
create their machine definitions. A complete description of components is
provided earlier in this chapter. - Objects and Attributes
- A component is implemented by one or more
configuration objects in Simics, and each object has several attributes
describing it. Configuring machines on the object and attribute level is
not supported in Simics, and such configurations may not work in
future versions.
Below is another example of a simple configuration based on
QSP-x86, that uses parameters to configure
two machines slightly differently that both run in the same Simics
session.
$freq_mhz = 2000
$host_name = "target0"
run-command-file "%script%/firststeps.simics"
$freq_mhz = 3000
$host_name = "target1"
run-command-file "%script%/firststeps.simics"
The parameters available for each predefined machine allows the user to do
minor modifications. It is also possible to extend the ready-to-run
configurations with additional components without creating new machine setups
from scratch.
Since the machine setup scripts are located in the read-only master
installation of Simics, they should not be modified. User files that add
new components should instead be placed in the corresponding
[project]\targets\architecture
Here is a short example of how to extend
the QSP-x86 to add a SATA disk:
# Add disk2
$disk2 = (create-sata-disk-comp $system.disk2 size = $disk2_size)
connect $system.mb.sb.sata_slot[2] $disk2.sata_slot
instantiate-components
Notice, that script requires you to provide a disk image and a valid
disk size. Essentially the script will run
another script, firststeps.simics, which will
create an instantiated QSP-x86 machine, then
a SCSI disk is created and connected to that machine, and finally the
new disk is instantiated.
It is possible to add many devices to an instantiated Simics machine
in a similar manner. In the case a device must be added to the target
machine before instantiation, write a script as described above.