HP (Hewlett-Packard) 520 5/XX Personal Computer User Manual


 
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4 Summary of the HP/Phoenix BIOS
HP/Phoenix BIOS (BIOS version: GX.07.xx)
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.
Devices, such as memory and hard disks, are configured automatically. The
user is not requested to confirm the change. However, the user is prompted
if a device is found to have gone missing since the previous boot. The user
can simply accept the new configuration by pressing .
During the POST, the BIOS and other ROM data are 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.
Test Description
System BIOS Tests
LED Test
Tests the LEDs on the control panel.
Processor Test
Tests the processor’s registers. Test failure causes the boot process to
abort.
System (BIOS) ROM Test
Calculates an 8-bit checksum. Test failure causes the boot process to
abort.
RAM Refresh Timer Test
Tests the RAM refresh timer circuitry. Test failure causes the boot process
to abort.
Interrupt RAM Test
Checks the first 64 KB of system RAM used to store data corresponding to
various system interrupt vector addresses. Test failures cause the boot
process to abort.
Shadow the System ROM
BIOS
Tests the system ROM BIOS and shadows it. Failure to shadow the ROM
BIOS will cause an error code to display. The boot process will continue,
but the system will execute from ROM. This test is not performed after a
soft reset (using and ).
Load CMOS Memory
Checks the serial EEPROM and returns an error code if it has been
corrupted. Copies the contents of the EEPROM into CMOS RAM.
CMOS RAM Test
Checks the CMOS RAM for start-up power loss, verifies the CMOS RAM
checksum(s). Test failure causes error codes to display.