Boot PROM Chip 和 NVRAM Chip

jndu

Incorrect NVRAM settings can cause system boot failure. For
example, during a flash PROM download, if a power failure occurs,
some of the contents of the NVRAM can become unusable.

Boot PROM Chip 和 NVRAM Chip 不是分开的2块吗？怎么在during a flash PROM download, if a power failure occurs,
some of the contents of the NVRAM can become unusable.？？？？？

race

NVRAM k可以理解成硬件芯片，PROM可以理解成里面的软件，就明白那些话了

jndu

The fact is the Openboot PROM Chip and NVRAM are two different chips.

jobandmiss

和BIOS及CMOS对比是一个道理呀。

jndu

I don't think so.

race

打开机器看看， 都在一个芯片里面

jndu

看这里：

Each Sun system has a boot PROM chip. This 1-Mbyte chip is typically
located on the same board as the central processing unit (CPU). Boot
PROM chips are usually found in a pluggable socket on older systems. As
of the 3.x PROM, they are permanently soldered to the main system
board.
The Ultra™ workstations use a reprogrammable boot PROM called a
flash PROM (FPROM). The FPROM allows you to load new boot program
data into the PROM by using software, instead of having to replace the
chip. A CD-ROM distributes these updates.
Desktop systems have a write-protect jumper that must be moved before
you can write to the PROM. You have to move the jumper because the
default position is write-protect. Refer to the Flash Programming Manual for
Ultra Desktop Systems, part number 802-3233-17, for the jumper location on
your system.

再看这里：

Another important hardware element in each Sun system is the NVRAM
chip. This removable chip is often located on the main system board.
The NVRAM module contains the electronically erasable programmable
read-only memory (EEPROM). The EEPROM stores user-configurable
parameters that have been changed or customized from the boot PROM’s
default parameters settings. This behavior gives you a certain level of
flexibility in configuring the system to behave in a particular manner for a
specific set of circumstances. A single lithium battery within the NVRAM
module provides battery backup for the NVRAM and the clock.

qgqceo

是两个不同的芯片来的，可以参考如下的图片。

qgqceo

看到图片左上角的NVRAM和OBP芯片。其联系和区别如下：