Kontron AM4211 - Manual (Page 55)

40 AM4211
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However, the command must be invoked with appropriate bridging parameters set. E.g. on an AT8404 carrier
with the AM4211 inside Bay 4, the syntax would be:
#
ipmitool -b 7 -t 0x80 kontron boot set 0 0
5.2.1 Switching between Firmware Images
The IPMI command used for image swap can be executed either from the bootloader shell with a predefined
script command or with a specific ‘ipmitool’ command either from the board itself, from an ATCA carrier or
from an external server.
5.3 Bootloader
On the AM4211 Advanced Mezzanine Card (AMC), the bootloader ‘u-boot‘ (universal bootloader) is used. The
bootloader initializes the main components of the board like CPU, DDR3 RAM, serial lines etc. for operation
and performs a power on self test (POST). After these steps have been finished, Linux kernel and application
are started from flash. Bootloader used on the AM4211 is a modified version from u-boot version 2011.03
included in the OCTEON SDK 2.2. The following section describes most of the differences from the original u-
boot that are used for the AM4211.
Generic u-boot features are not described in this section. Please read the u-boot documentation if the
requested information is not describe in this section.
5.3.1 Bootloader shell and options
The boot process can be interrupted by typing the bootstopkey phrase “stop”. This will open a bootloader
command line interface.
Entering “?” provides a list of possible built-in commands, “printenv” provides a list of current environment
settings. The bootloader shell can be used to customize boot options and system startup by changing some of
its environment variables. A list of available environment variables and its description can be seen in the
table below.
Note:
In case that no ipmitool is available on a carrier or host server and image 0 has been corrupted, the
board will perform an image swap automatically triggered by the system watchdog. An image swap
is performed automatically by the MMC after the 3rd unsuccessful boot attempt (3 consecutive
boot-up watchdog triggers)