Bios Post Checkpoint Codes - Acer Altos R310 Service Manual

BIOS POST Checkpoint Codes

The POST code checkpoints are references and instructions used duing the BIOS pre-boot process.
The following table describles the checkpoints and associated beep codes, if any, that may occur during
the POST portion of the BIOS.
Checkpoint Code
01h
02h
03h
04h
06h
07h
08h
09h
0Ah
0Bh
0Ch
0Eh
0Fh
10h
11h
53
Beep Code
One short beep
before boot
Verify Real Mode. If the CPU is in protected mode,
turn on A20 and pulse the reset line, forcing a
shutdown 0.
NOTE: Hook routine should not alter DX, which
holds the powerup CPUID.
Disable Non-Makable Interrupts (NMI).
Get CPU type from CPU registers and other
methods.
Save CPU type in NVRAM.
NOTE: Hook routine should not alter DX, which
holds the powerup CPUID.
Initialize system hardware. Reset the DMA
controllers, disable video, clear any pending
interrupts from the real-time clock and setup port B
register.
Disable system ROM shadow and start to execute
ROMEXEC code from the flash part. This taks is
pulled into the build only when the ROMEXEC
relocatoin is installed.
Initialize chipset registers to the lnitial POST Values.
Set in-POST flag in CMOS that indicates we are in
POST. If this bit is not cleared by post -
ClearBootFlag(AEh), the BIOS no next boot
determines that the current configuration caused
POST to fail and uses default values for
configuration.
Clear the CMOS diagnostic byte (register E). Check
the real-time clock and verify the battery has not lost
power. Checksum the CMOS and verify it has not
been corrupted.
Initialize CPU registers.
Enable CPU cache. Set bits in CMOS related to
cache.
Set the initial POST values of the cache registers if
not integrated into the chipset.
Set the initial POST values of registers in the
integrated I/O chip.
Enable the local bus IDE as primary or secondary
depending on other drives detected.
Initialize power management
General dispatcher for alternate register initialization.
Set initial POST values for other hardward devices
defined in the register tables.
Description
Altos R310