AR# 20708

CORE Generator - Error messages "Could not reserve enough space for object heap" and "Could not create the Java virtual machine"


When I attempt to launch the CORE Generator software from the command line or open a JAVA-based IP core, the following errors occur:

Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine

ERROR:coreutil:576/424 (# depends on SW version) - An error occurred while running Java. Please examine the console or coregen log file for a specific IP related error.

For more information please search the Xilinx Answers Database for this error:
WARNING:coreutil:266 - Could not remove outfile.

An Error occurred during Customization.


This error occurs if Java cannot allocate the requested amount of memory on the machine in use.

To work around this issue, Set the Java Memory allocation to a smaller size.

The amount of memory available varies between different systems.

In most cases, this error occurs with the default memory settings.

The default system memory used by the CORE Generator 10.1 and later is 512 MB on Windows and 1024 MB on Unix.

For Windows, set a value smaller than 512 MB. 

For Unix, set a value smaller than 1024 MB.

To change the amount of memory allocated, change the "Memory available for Java" value in the CORE Generator tool, under File -> Preferences... -> Java. 

Note: If using ISE Design Suite 12.1, the Java heap size needs to be set from command line or with the JAVA_TOOL_OPTIONS environment variable; see (Xilinx Answer 35389).

Memory allocation can be changed when launching the CORE Generator tool from the command line; using the "coregen -J" option as shown in the following example: 

coregen -J Xmx256m 

Memory allocation can also be changed by using the JAVA_TOOL_OPTIONS environment variable as in the following example.
The total amount of physical memory, plus the virtual memory, must be greater than or equal to the command line memory setting for CORE Generator.

Setting the "-J Xmx" option to a larger value also ties up this amount of memory for CORE Generator used during your session.

Other applications cannot utilize this memory until after the CORE Generator software is terminated.

The maximum heap size is machine-dependent.

Many Windows NT systems cannot allocate much more than about 512 MB.

If CORE Generator requires more memory than is available on the system, it fails to open. 

If multiple versions of the Xilinx ISE design tools are installed on the same machine, make sure that the PATH variable lists the location of the %Xilinx%\bin\nt directory before any ISE installed version.

(Where %Xilinx% represents the current install path pointed to by the Xilinx variable.)

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AR# 20708
Date 08/12/2014
Status Active
Type General Article
Tools More Less