Managing the JavaOS Checksum

Each time you receive a new copy of JavaOS, you can configure the DHCP server to deliver the new copy to JavaStation computers by following the first set of instructions below. To disable JavaOS updating on the JavaStation computers, follow the second set of instructions.

To Configure the DHCP Server for a New JavaOS

1. Determine the checksum.

   The checksum is contained in the first four bytes of the last 12 bytes of the JavaOS binary file. To determine the checksum, type:

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   % tail -4c /export/root/javaos/JSIIep/javaos | od -xv \
   	| nawk '{print $2 $3}'
   14eb02a1 

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2. Use dhtadm to add the new checksum to the DHCP configuration.

   The command to add a new checksum is:

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   % dhtadm -M -m SUNW.JSIIep -e JOSchksm=0x
   checksum 
   

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For example,

% dhtadm -M -m SUNW.JSIIep -e JOSchksm=0x14eb02a1 

At boot up, each JavaStation will update its flash memory with the new JavaOS and then reboot using the new JavaOS.

To Disable JavaOS Updating

1. Set the checksum to zero:

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   % dhtadm -M -m SUNW.JSIIep -e JOSchksm=0
   

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   or delete the checksum entirely from the DHCP configuration by typing:

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   % dhtadm -M -m SUNW.JSIIep -e JOSchksm= 
   

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   Note that there is nothing after the equal sign.