Toshiba QOSMIO G20 manual Debug port Boot mode error status 4/8, Bios

2.4 System Board Troubleshooting 2 Troubleshooting Procedures

Table 2-4 Debug port (Boot mode) error status (4/8)

D port status	Inspection items	Details
		Forwards the area of C0000h to EFFFFh to
		PCI (prohibition of DRAM)
		Sets resume error request
	Copying ROM/RAM of system	(When error occurred, it halts.)
	BIOS
F104h	SMRAM initialization
	WakeUp factor check
	SMRAM base rewriting and
	CPU state map saving for
	BIOS
	Permission of SMI based on
	ASMI
F105h	Initialization of devices which	PIT test (at Cold boot only) and initialization
	need initialization before PCI	Setting of test pattern to channel 0 of PIT#0
	bus initialization	Check whether the set test pattern can be
		read.
		Initialization of PIT channel 0
		(Setting of timer interruption interval to 55ms)
		Initialization of PIT channel 2
		(Setting of the sound generator frequency to
		664Hz)
		Test of PIT channel 1
		(Check whether the refresh signal works normally
		in 30 micro-s refresh interval)
		(The system halts when the time is out.)
		Test of PIT channel 2
		(Check if the speaker gate works properly.)
		CPU clock measurement
		Check of parameter block A
		Permission of SMI except auto-off function
		Control on excess of rated input power
		Battery discharge current control (1CmA)
		AC adapter rated over current control
		Dividing procedures for time measuring by IRT
		Setting for clock generator
		CPU Initialization
		Update of micro code
		Judge of CPU type
		Geyserville support check
		Setting of CPU clock to “high"
		Graphics Aperture Size setting

2-24 [CONFIDENTIAL] QOSMIO G20 Maintenance Manual (960-511)