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CP3923 User Guide
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4.3
Bootloader
On the CP3923 CPCI Ethernet Switch board, the bootloader 'u-boot' (universal bootloader) is used. The bootloader initial-
izes the main components of the board like Unit Computer, DDR2 RAM, serial lines etc. for operation and performs a power
on self test (POST). After these steps have been finished, kernel and application are started from flash.
4.3.1
Power On Self Test
4.3.1.1
Test Routines
Upon power on or system reset, the bootloader performs the following power on self tests (POST):
In the case that a POST fails, a POST error code is written into the postcode register of the onboard CPLD. The boot process
is not stopped as there are good chances that the board can finish startup sequence successfully. The postcode register is
also accessible by the PM which can report error codes to a separate management instance.
The following table shows the POST code values written into the CPLDs postcode register in case of a POST error.
Table 4-1:
POST tests
Test
Description
Serial
Onboard Unit Computer serial controller loopback test
I2C
Check for presence of onboard I2C devices
PCI Express
Check for PCI Express switch device presence
Serviceport
Onboard PPC405EX ethernet internal loopback test
DDR RAM data line
Data line test. Checks for stucked or shortened data lines
DDR RAM address line
Adress line test. Checks for stucked or shortened address lines
DDR RAM memory cells
Checkerboard standard test algorithm
Bootloader environment
Check for valid bootloader environment (CRC correct or both CRCs are
0xFFFFFFFF == not initialized)
VPD area
Check for valid VPD area (CRC is valid)
Table 4-2:
POST routines and error codes
Device
Test
0x00
All POST were successful
0x01
Serial POST failed
0x02
I2C POST failed
0x04
PCIe POST failed
0x08
Ethernet POST failed
0x10
Environment POST failed
0x20
VPD POST failed
0x40
Memory data/address line POST failed
0x80
Memory device cells POST failed
