A-4 Appendix: CPU features
A.4 Debug Code Table
Code Description
CPU INIT
CPU Initiation
DET CPU
Test CMOS R/W functionality.
CHIPINIT
Early chipset initialization:
-Disable shadow RAM
-Disable L2 cache (socket 7 or below)
-Program basic chipset registers
DET DRAM
Detect memory
-Auto-detection of DRAM size, type and ECC.
-Auto-detection of L2 cache (socket 7 or below)
DC FCODE
Expand compressed BIOS code to DRAM
EFSHADOW
Call chipset hook to copy BIOS back to E000 & F000 shadow RAM.
DC XCODE
Expand the Xgroup codes locating in physical address 1000:0
INIT IO
Initial Superio_Early_Init switch.
CLR SCRN
1. Blank out screen
2. Clear CMOS error ag
INIT8042
1. Clear 8042 interface
2. Initialize 8042 self-test
ENABLEKB
1. Test special keyboard controller for Winbond 977 series Super I/O chips.
2. Enable keyboard interface.
DIS MS
1. Disable PS/2 mouse interface (optional).
2. Auto detect ports for keyboard & mouse followed by a port & interface swap
(optional).
3. Reset keyboard for Winbond 977 series Super I/O chips.
R/W FSEG
Test F000h segment shadow to see whether it is R/W-able or not. If test fails, keep
beeping the speaker.
DET FLASH
Auto detect ash type to load appropriate ash R/W codes into the run time area in
F000 for ESCD & DMI support.
TESTCMOS
Use walking 1’s algorithm to check out interface in CMOS circuitry. Also set real-time
clock power status, and then check for override.
PRG CHIP
Program chipset default values into chipset. Chipset default values are MODBINable
by OEM customers.
INIT CLK
Initial Early_Init_Onboard_Generator switch.
CHECKCPU
Detect CPU information including brand, SMI type (Cyrix or Intel) and CPU level (586
or 686).
INTRINIT
Initial interrupts vector table. If no special specied, all H/W interrupts are directed to
SPURIOUS_INT_HDLR & S/W interrupts to SPURIOUS_soft_HDLR.
REC MPS
Initial EARLY_PM_INIT switch.
Reserved
Load keyboard matrix (notebook platform)
Reserved
HPM initialization (notebook platform)
SET FDD
1. Check validity of RTC value:
e.g. a value of 5Ah is an invalid value for RTC minute.
2. Load CMOS settings into BIOS stack. If CMOS checksum fails, use default value
instead.
3. Prepare BIOS resource map for PCI & PnP use. If ESCD is valid, take into
consideration of the ESCD’s legacy information.
4. Onboard clock generator initialization. Disable respective clock resource to empty
PCI & DIMM slots.
5. Early PCI initialization:
-Enumerate PCI bus number
-Assign memory & I/O resource
-Search for a valid VGA device & VGA BIOS, and put it nto C000:0.
INITINT9
Initialize INT 09 buffer