Kontron SBC-815ET-VER, User Manual

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page 82 SBC-815ET-VER User’s Guide
BIOS POST Check Point List
AWARDBIOS provides all IBM standard Power On Self Test (POST) routines as well as
enhanced AWARDBIOS POST routines. The POST routines support CPU internal
diagnostics. The POST checkpoint codes are accessible via the Manufacturing Test
Port (I/O port 80h).
Whenever a recoverable error occurs during the POST, the system BIOS displays an
error message explaining the problem and offers a solution.
During the POST, the BIOS signals a checkpoint by issuing one code to I/O address
80H. This code can be used to establish how far the BIOS has executed through the
power-on sequence and what test is being performed. This is done to help troubleshoot
a faulty board.
If the BIOS detects a terminal error condition, it will halt the POST process and attempt
to display the checkpoint code written to port 80H. If the system hangs before the BIOS
detects the terminal error, the value at port 80H will be the last test performed. In this
case, the terminal error cannot be displayed on the screen. The following POST
checkpoint codes are valid for all AWARDBIOS products with a core BIOS date of
07/15/95 version 6.27 (Enhanced).
Code Description
CFh Test CMOS R/W functionality.
COh Early chipset initialization: -Disable shadow RAM -Disable L2 cache (socket 7 or
below) -Program basic chipset registers
Clh Detect memory -Auto-detection of DRAM size, type and ECC. -Auto-detection of
L2 cache (socket 7 or below)
C3h Expand compressed BIOS code to DRAM
C5h Call chipset hook to copy BIOS back to E000 & F000 shadow RAM.
Ohl Expand the Xgroup codes locating in physical address 1000:0
02h Reserved
03h
Initial Superio Early Init switch.
04h Reserved
05h
1. Blank out screen 2. Clear CMOS error flag
06h Reserved
07h
1. Clear 8042 interface 2. Initialize 8042 self-test
08h 1. Test special keyboard controller for Winbond 977 series Super I/O chips. 2.
Enable keyboard interface.
09h Reserved
OAh Disable PS/2 mouse interface (optional). Auto detect ports for keyboard &
mouse followed by a port & interface swap (optional). Reset keyboard for
Winbond 977 series Super I/O chips.
OBh Reserved