Reading Nonvolatile Memory (NVM)

Reading stable storage

Stable storage stores boot path information along with other critical system parameters. Like NVM, stable storage maintains its information through system crashes and failures. Unlike NVM, stable storage maintains its information even if the memory card, containing stable storage, is removed from the backplane.

To read the contents of stable storage, enter READSS nn at the prompt, where nn is the location to be read:

   ISL> READSS 40



      Address 40 contains 0XFFFFFF08

For information on the contents and locations of stable storage, refer to Appendix C “Reading Stable Storage and Nonvolatile Memory”.

Reading and setting the hardware clock

The ISL utility CLKUTIL reads and sets the battery backed-up hardware clock. This clock maintains Greenwich Mean Time (GMT) independently of the software clock that is displayed when you enter the ISL START utility or any of the other ISL utilities that support the software clock. (Refer to example 3-7 for an example of the software clock interaction.). The CLKUTIL utility, therefore, reads the date and time that were previously set with CLKUTIL, but does not itself reflect the changes that you may make while in any other ISL utility.

The hardware clock should be set to GMT if the clock displays are to be correct on the booted system. The hardware clock provides the basis for time displays that are part of some ISL utilities.

When the local time is entered during particular ISL utilities, the system computes an offset and stores it in stable storage. During a boot, the GMT and this offset are combined to produce the local time, displayed on the console.

To read or set the hardware clock, enter:

   ISL> CLKUTIL

The system responds with the following banner:

   SYSTEM FOR ISL STAND ALONE UTILITIES. [IHO, SPU LAB]

   Version 1.0



   ****** clock utility ************ ver 1.0 ***** 11/6/86

   enter command :  (r) read clock, (s) set clock >

To read the clock, enter r at the CLKUTIL prompt:

   enter command :  (r) read clock, (s) set clock > r

The system responds with a message similar to the following:

   THU, JAN 1,  1988,  9:00:16 AM

To set the clock, enter s at the CLKUTIL prompt:

   enter command :  (r) read clock, (s) set clock > s

The system responds with a message similar to the following:

   enter date  mm/dd/yyyy

When the enter date prompt appears, enter the date in the correct format: mm is a two-digit number, 1-12, representing the month; dd is a two-digit number, 1-31, representing the day of the month; and yyyy is a four-digit number representing the year. (You can also enter just the last two digits for the year.)

The system continues by issuing the following prompt:

   enter time hh:mm:ss

Enter the time using Greenwich Mean Time in 24-hour format.

The system requests verification of the adjusted date and time by issuing a message similar to the following:

   THU, JAN 7, 1988, 11:17:00 PM

   ok (y/n)?

Entering Y returns a message of:

   clock set!

Entering N returns you to the enter date prompt.

Pressing Return at the enter command prompt returns you to the ISL prompt.