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2 bootloader shell and options, Bootloader shell and options – Kontron AM4204 User Manual

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Table 5-10:Bootloader POST Code values

5.2.2

Bootloader shell and options

The boot process can be interrupted by entering 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.

Table 5-11: Bootloader environment variables

POST Code Value

Description

0x00

All POST were successful

0x10

Cavium BIST failed

0x20

Memory data line POST failed

0x40

Memory address line POST failed

0x80

Memory device cells POST failed

Name

Type

Description

boardmacaddr

Var

Contains the default base MAC address for the Octeon plus Ethernet interfaces. This

variable is automatically set by the bootloader when the MAC address was read from

the MMC/KCS interfaces. This should only be set manually when disable_kcs=yes or

ignore_kcserr=yes to provide a “fallback” MAC address, when the KCS/MMC

interface is not available or fails

bootcmd

Script

This variable defines a command string that is automatically executed when the

initial countdown is not interrupted.

This command is only executed when the variable bootdelay is also defined!

bootcmddata0a

Script

Contains the standard startup script for loading OS image from flash partition

mtd4, which is a raw partition. The image is started using bootoctlinux command.

bootcmddata0b

Script

Contains the standard startup script for loading OS image from flash partition

mtd5, which is a JFFS2 partition by default. The image is started using a

combination of fsload/bootoctlinux command.

bootcmdnet

Script

Contains the standard startup script for loading OS image from network

bootcmdprd

Script

Contains the standard startup script for use during board production

bootdelay

Var

After reset, U-Boot will wait this number of seconds before it executes the

contents of the bootcmd variable. If the bootstopkey phrase is typed

during this time, the bootloader command line interface is entered.

Set this variable to 0 boots without delay. Be careful: depending on the

contents of your bootcmd variable, this can prevent you from entering

interactive commands again forever!

Set this variable to -1 to disable autoboot.
default: 5 for flash based bootloader, -1 for RAM resident bootloader

bootsource

Var

When the standard boot sequence is used, contains the boot source, either data0a,

data0b, net, prd to select the respective boot sequence to activate. It is only used

when bootcmd contains the default startup script, which may be overridden by the

user.
default: data0a