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ski - Man Page

An IA-64 Instruction Set Simulator


ski [-help] [-i file] [-rest file] [-nonet]    [-srcroot dir] [-forceuser]  [-forcesystem] [-strace]    [-palen n] [-valen n] [-ridlen n] [-keylen n] [-grfile n]

xski [-help] [-i file] [-rest file] [-noconsole] [-nonet]     [-srcroot dir] [-forceuser] [-forcesystem] [-strace]     [-palen n] [-valen n] [-ridlen n] [-keylen n] [-grfile n]

bskinc [-help] [-i file] [-rest file] [-noconsole] [-nonet]     [-forceuser] [-forcesystem] [-icnt file] [-strace] [-palen n]     [-valen n] [-ridlen n] [-keylen n] [-grfile n]


Ski is an IA-64 instruction set simulator from Hewlett-Packard Company.  It simulates the IA-64 architecture as defined by the architecture manual.  This is not a full platform simulator, i.e., no system chipset or PCI bus simulation is done.  However it supports the full instruction set of the architecture, including privileged instructions and associated semantics.

Ski can be used in two operating mode: user- and system-mode. In user mode, you can run user level applications directly on top of the simulator.  The emulation stops at the system call boundary. The system call is emulated by calling the host OS, such as x86 Linux. Conversions between 64-bit and 32-bit parameters are done by Ski as needed. This allows fast execution of user programs. Most system calls are emulated, though the emulation is not always 100 percent accurate.

In system-mode, operating-system kernel development and execution is possible because interrupts and virtual memory behaviors are simulated. In this mode you can actually run the Linux kernel and, once booted, user applications can be run on top of the simulated kernel.

The ski simulator comes with three different interfaces. The simplest one is the batch mode, called bskinc a shell running a script.

There is also a full-text curses-based mode, where you can interact with the simulator to inspect code, set breakpoints, etc. This version is called ski

Finally there is a graphical version called xski which gives you several windows where you can look at the code, inspect register contents, etc.

All three modes provides the same core simulation, only the interface is different.



Prints the list of supported options for the specific interface required.  Not all options are available in every possible interface.


When running in kernel mode, this option tells the simulator not to probe for existing Ethernet interfaces on the host. This way the Linux kernel won't detect any device. This option is useful when you don't want to run the simulator as root (or setuid to root). For networking support root privilege is required.

-srcroot directory

Specify the directory where the program sources can be found.  This option is only useful when combined the "mixed mode" display (see the "pm" command inside Ski).


Do not use an xterm as the default output console, but use the current tty. This option is only useful when ski is invoked in batch mode. It allows  to run in the current terminal window. This is used mostly within the NUE(1) environment.


Force the simulator into user-mode.  The simulator normally auto-detects which mode to run in, but this option is available to force user-mode in case auto-detection fails for some reason.


Force the simulator into system-mode.  The simulator normally auto-detects which mode to run in, but this option is available to force system-mode in case auto-detection fails for some reason.


This option displays all the system calls executed by the user level programs. It is only valid when running in user-mode. The output looks like a highly simplified version of output from strace(1).

-i file

Process initialization <file> at startup.


Store instruction counts in <file>.


Restore simulation state from <file>.


Display execution run-time and instruction rate.

-palen <n>

Implemented physical address bits.  Default: n=63

-valen <n>

Implemented virtual address bits.  Default: n=61

-ridlen <n>

Implemented RR.rid bits.  Default: n=24

-keylen <n>

Implemented PKR.key bits.  Default: n=24

-grlen <n>

General Register file size.  Default: n=128

Running in user-mode

To run a simple IA-64 program in user-mode only, you can type in the following:

$ bskinc my_ia64_prg

This will force execution is the current terminal and in batch mode.

IMPORTANT: To run dynamically linked IA-64 binaries, it is necessary to have IA-64 versions of the necessary shared libraries installed.  On x86 Linux, this is most easily accomplished by installing the NUE(1) environment.

Running in system-mode

To run a Linux kernel on top of the simulator, you need several components:

- a Linux kernel compiled to use the HP-simulator.  It needs to have the CONFIG_SIMSERIAL, CONFIG_SIMSCSI, and CONFIG_SIMETH options turned on.

- a boot loader that goes with it (compiled with "make boot" in the kernel source tree).

- a disk image file with IA-64 binaries on it.

Please refer to extra documentation to learn in greater details how to build those 3 components.

Once you have those components, you launch execution by simply typing:

    $ ski bootloader vmlinux simscsi=/path/sd simeth=eth0

In this example, the simscsi= option informs the Linux kernel where to find the SCSI disk images. Here /path/sd is just the prefix, the kernel will automatically look for /path/sd{a,b,c,...}. So the disk image must use the full name, i.e., /path/sda. The simeth= indicates which local interface to use for the simulated Ethernet driver. The simulator must be run with root privilege to get the networking emulation to work.

You can specify other options on the command line, just like you would do at the LILO boot prompt for instance.

Getting help inside ski

When you run ski in interactive mode via ski or xski, you can get help on commands by typing help.

When running in curses mode, you must make sure that you have the PAGER environment variable set to whatever is your preferred pager command. It is  usually set to more(1) or less(1). If the variable does not exist ski will default to using less(1).  Note that less(1) usually behaves the best when interacting with ski.

Using Xski

In this version (1.1.0) of ski, the X11 interface has not been built.  If you would like such a GUI, please feel free to contribute patches to convert the current Motif version to something more modern.

Environment Variables


If this environment variable is set (the value is unimportant), the ski-fake-xterm(1) utility will be used for output to stdout, instead of xterm(1).  This will result in a temporary file created in the current working directory with a name of the form "ski.XXXXXX", where "XXXXXX" can be any six characters.

See Also

qemu(1), bochs(1)


Hewlett-Packard Company
Stephane Eranian <eranian@hpl.hp.com>
David Mosberger  <davidm@hpl.hp.com>

Referenced By

The man pages bski(1), bskinc(1), gski(1) and xski(1) are aliases of ski(1).

Development Tools Hewlett-Packard Company