AI2524 Router Card User’s Manual
Page 7-30 August 1997
2524UM
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 upgrad e 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 informati on.
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. Flas h 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 o n the s pecified 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