AI2524 Router Card User’s Manual

Flash memory. It is a lower-cost software upgrade solution than dual- bank Flash, which requires two banks of Flash memory on one SIMM.

The Flash load helper software upgrade process is simple and does not require additional hardware; however, it does require some brief net- work downtime. A system image running from Flash can use Flash load helper only if the boot ROMs support Flash load helper. Other- wise, you must perform the Flash upgrade manually. Refer to Manu ally Boot from Flash, for more information.

Flash load helper is an automated procedure that reloads the ROM- based image, downloads the software to Flash memory, and reboots to the system image in Flash memory. Flash load helper performs checks and validations to maximize the success of a Flash upgrade and mini mize the chance of leaving Flash memory either in an erased state or with a file that cannot boot.

In run-from-Flash systems, the software image is stored in and exe- cuted from the Flash EPROM rather than from RAM. This method re- duces memory cost. A run-from-Flash system requires enough Flash EPROM to hold the image and enough main system RAM to hold the routing tables and data structures. The system does not need the same amount of main system RAM as a run-from-RAM system because the full image does not reside in RAM. The AI2524 is a Run-from-Flash system.

Flash load helper:

zConfirms access to the specified source file on the specified server before erasing Flash memory and reloading to the ROM image for the actual upgrade.

zWarns you if the image being downloaded is not appropriate fo the system.

zPrevents reloads to the ROM image for a Flash upgrade if the sys- tem is not set up for automatic booting and if the user is not on the console terminal. In the event of a catastrophic failure during the upgrade, Flash load helper can bring up the boot ROM image as last resort rather than forcing the system to wait at the ROM mon- itor prompt for input from the console terminal.

zRetries Flash downloads automatically up to six times. The retry sequence is:

First try Immediate retry Retry after 30 seconds

Reload ROM image and retry Immediate retry

Retry after 30 seconds

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August 1997

 

2524UM

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AIS user manual AI2524 Router Card User’s Manual