Acer G520 series manual Bootblock Initialization Code Checkpoints

168 Appendix F: Diagnostic Code Checkpoints

Diagnostic LED Decoder

Check

point

G=Green, R=Red, A+Amber Description

MSBLSB

B1	R	OFF	R	A	Save system context for
					ACPI.
00	OFF	OFF	OFF	OFF	Passes control to OS
					Loader (typically INT19h).

Bootblock Initialization Code Checkpoints

The Bootblock initialization code sets up the chipset, memory and other components before system memory is available. The following table describes the type of checkpoints that may occur during the bootblock initialization portion of the BIOS:

Check point

Diagnostic LED Decoder

G=Green, R=Red, A+Amber

MSB LSB

Description

Before D1					Early chipset initialization
					is done. Early super I/O
					initialization is done
					including RTC and
					keyboard controller. NMI
					is disabled.
D1	R	R	OFF	A	Perform keyboard
					controller BAT test. Check
					if waking up from power
					management suspend
					state. Save power-on
					CPUID value in scratch
					CMOS.
D0	R	R	OFF	R	Go to flat mode with 4GB
					and GA20 enabled. Verify
					the bootblock checksum.