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5 Power-On Self-Test and Error Messages
Order in Which Tests are Performed
Order in Which Tests are Performed
Each time the system is powered on, or a reset is performed, the POST is
executed. The POST process verifies the basic functionality of the system
components and initializes certain system parameters.
The POST starts by displaying a graphic screen with the initial HP “Vectra”
logo. If the POST detects an error, the error message is displayed inside a
view system errors
screen, in which the
error message utility
(EMU) not
only displays the error diagnosis (localized into 11 languages), but the
suggestions for corrective action. Error codes are no longer displayed.
To see the tests performed during the POST, press
when the initial
HP “Vectra” logo appears, and the display will switch to text mode. In this
mode, a summary configuration screen will be displayed at the end of the
POST. Pressing the PAUSE/BREAK key at any time will allow you to inspect
the screen contents. Press any key to resume.
Devices, such as memory and newly installed hard disks, are configured
automatically. The user is not requested to confirm the change. Newly
removed hard disks are detected, and the user is prompted to confirm the
new configuration by pressing
. Note, though, that the POST does not
detect when a hard disk drive has been changed.
During the POST, the BIOS and other ROM data is copied into high-speed
shadow RAM. The shadow RAM is addressed at the same physical location
as the original ROM in a manner which is completely transparent to
applications. It therefore appears to behave as very fast ROM. This
technique provides faster access to the system BIOS firmware.
The table on the following page lists the POST routines in the order in which
they are executed (from the shadow RAM). If the POST is initiated by a soft
reset,
and
, the RAM tests are not executed and shadow
RAM is not cleared. In all other respects, the POST executes in the same
way following power-on or a soft reset.
