Core Devices

CPU

A CHARON-AXP emulated CPU is configured with the "ace_mode" parameter enabling the high performance Advanced CPU Emulation mode ("ACE"). The ACE option optimizes the HP Alpha instruction interpretation and significantly improves performance. It also requires approximately twice the amount of host memory to store the optimized code.

ACE optimization is performed dynamically during execution. It does not need to write optimized code back to disk, ACE provides its full capability instantly. The optimization does not compromise the HP Alpha instruction decoding; CHARON-AXP remains fully HP Alpha hardware compatible and completely transparent to the HP Alpha operating systems and applications.

Parameter	Type	Values
ace_mode	Boolean	true or false.

This statement enables the ACE mode if the CHARON-AXP license permits it. If this statement is omitted from the CHARON-AXP configuration file and the license permits it, "true" is the default, otherwise "false" is the default. For test purposes the ACE mechanism can be disabled with:

set cpu ace_mode=false

"set cpu ace_mode=true" is ignored when the license does not permit ACE operation.

The CHARON-AXP log file displays the status of the ACE option.

The ACE mode is disabled when the host system does not meet the minimum physical requirements for this operation. If the emulator appears to not run at its normal performance, check the log file for a change in the ACE mode and verify that sufficient host resources, especially memory, are available.

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RAM

The CHARON-AXP memory subsystem is permanently loaded and has the logical name "ram".

Parameter	Type	Description
size	Numeric	Size of the emulated memory in MB.

Example:

set ram size = 2048

The amount of memory is capped at a maximum, this is defined in the CHARON license key. If the host system cannot allocate enough memory to map the requested emulated memory, CHARON-AXP generates an error message in the log file and reduces its effective memory size.

The following table lists the values of emulated RAM for various hardware models of virtual HP Alpha systems:

Hardware Model	RAM size (in MB)
	Min	Max	Default	Increment
AlphaServer 400	64	1024	512	64
AlphaServer 800	256	8192	512	256
AlphaServer 1000	256	1024	512	256
AlphaServer 1000A	256	1024	512	256
AlphaServer 1200	256	32768	512	256
AlphaServer 2000	64	2048	512	64
AlphaServer 2100	64	2048	512	64
AlphaServer 4000	64	32768	512	64
AlphaServer 4100	64	32768	512	64
AlphaServer DS10	64	32768	512	64
AlphaServer DS15	64	32768	512	64
AlphaServer DS20	64	32768	512	64
AlphaServer DS25	64	32768	512	64
AlphaServer ES40	64	32768	512	64
AlphaServer ES45	64	32768	512	64
AlphaServer GS80	256	65536	512	256
AlphaServer GS160	512	131072	512	512
AlphaServer GS320	1024	262144	1024	1024

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TOY

CHARON-AXP maintains its time and date using the "toy" (time-of-year) component. In order to preserve the time and date while a virtual system is not running, the TOY component uses a binary file on the host system to store the date and time relevant data. The name of the file is specified by the “container” option of the "toy" component.

Parameter Type Description

container

Text string

Specifies a name for the file in which CHARON-AXP preserves the time and date during its “offline” period. This file also keeps some console parameters (such as the default boot device).

By default it is left unspecified.

it is recommended to specify the full path to the TOY file.

sync_to_host

Text string

Specifies whether and how the guest OS time is synchronized with the CHARON host time.

Syntax:

set TOY sync_to_host = "{as_vms | as_tru64 | as_is}[, nowrite]"

where:

Parameter	Description
as_vms	If the guest OS is OpenVMS/AXP and its date and time must be set to the host's date and time each time it boots.
as_tru64	If the guest OS is Tru64 UNIX and its date and time must be set to the host's date and time each time it boots.
as_is	If the TOY date and time must be set to the host's UTC date and time
nowrite	Disable undesirable updates to the TOY from the guest OS.

Example:

set TOY sync_to_host = "as_vms, nowrite"

To synchronize the guest OS with TOY, use the following commands:

On OpenVMS/AXP On Tru64 UNIX

$ set time

# date -u `consvar -g date | cut -f 3 -d ' '`

The default value is "not specified" - it means that by default CHARON does not synchronize its guest OS time with the CHARON host time, but collects date and time from the file specified with "container" parameter.

If "sync_to_host" parameter is specified there is no need to specify "container" parameter in addition.

Example:

set toy container="C:\Charon\my_virtual_system.dat"

The CHARON-AXP time zone may be different from that of the host system. Correct CHARON time relies on the correctness of the host system time to calculate the duration of any CHARON “offline” periods. (i.e. while the virtual system is not running). Every time CHARON comes on line it calculates a Delta time (the system time is used if there is no TOY file). Therefore, if the host system time is changed while CHARON is not running, the CHARON time may be incorrect when CHARON is restarted and the CHARON time must be set manually.

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ROM

The System Flash ROM file conserves specific parameters between reboots.

Parameter

Type

Description

container

Text string

Specifies the name of a file in which CHARON-AXP stores an intermediate state of its Flash ROM. This state includes, for example, most of the console parameters.

By default it is left unspecified.

it is recommended to specify the full path to this file

Example:

set rom container=”C:\Charon\my_virtual_system.rom”

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Auto Boot

CHARON-AXP systems can be configured to boot the operating system automatically at start up.

Console Parameter Description

auto_action restart

Determines whether CHARON-AXP boots automatically if the correct boot flags are set (and saved in the HP Alpha console files).

Example:

>>>set bootdef_dev dka0>>>set auto_action restart

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