Emerson MVME2500 manual Using the Persistent Memory Feature

Boot System

3.TFTP the files from the server to local memory, then boot: run vxboot

6.4Using the Persistent Memory Feature

Persistent memory means that the RAM's memory is not deleted during a reset. Power cycling, or by temporarily removing the power and then powering up the blade again, will delete the memory content. Persistent memory feature is enabled by default.

This feature can be useful in many situations, including:

Analyzing kernel logs after a Linux kernel panic

Defining a particular memory region for the persistent storage of application specific data

Analyzing Kernel Log Files after a Kernel Panic

When a board that is running the Linux OS indicates a kernel panic, issue a reset (through the face plate button, for example) to analyze the cause, then subsequently analyze kernel log files. The persistent memory feature keeps the log files available in the memory.

To analyze the kernel log files:

1.Issue a reset.

2.Connect to U-Boot. For more information, see Accessing U-Booton page 103.

3.Enter the following command to obtain memory addresses of the kernel log files:.locate_kernel_log (1)

The memory addresses of any found kernel log files will be displayed.

4.Enter the following command to display the kernel logfile at any of these memory addresses: .printf (<memory address>)

The persistent memory is useful in application-specific data storage. The standard U-Boot variable pram can be used to reserve a memory region at the end of the physical memory to prevent it from being overwritten. U-Boot reports less memory to the Linux kernel through the mem parameter, indicating that the operating system should not use it either.

For more information, see the U-Boot documentation.

MVME2500 Installation and Use (6806800L01H) 107