hiltrs.blogg.se

1. #U BOOT CONFIGURATION STEPS HOW TO#
2. #U BOOT CONFIGURATION STEPS INSTALL#
3. #U BOOT CONFIGURATION STEPS SERIAL#
4. #U BOOT CONFIGURATION STEPS MAC#

# MTD SPI-dataflash example # MTD device nameĝevice offsetĞnv. sizeğlash sector size Number of sectors /dev /mtd1 0x0000 0x2000 0x10000 # Futhermore, if the Flash sector size is ommitted, this value is assumed to # be the same as the Environment size, which is valid for NOR and SPI-dataflash # NOR example # MTD device nameĝevice offsetĞnv. # Notice, that the "Number of sectors" is ignored on NOR and SPI-dataflash. # Up to two entries are valid, in this case the redundant # environment sector is assumed present. Vi /etc/fw_env.config # Configuration file for fw_(printenv/saveenv) utility.

#U BOOT CONFIGURATION STEPS INSTALL#

You need to install and configure uboot-envtools:

#U BOOT CONFIGURATION STEPS HOW TO#

However there are several steps to be able to use the above commands effectively.įirst of all you must tell the fw_* tools where the U-Boot environment is located.Īlso, the bootloader partition will likely be mounted read-only and one must change this somehow.Īn example on how to change this, is here: TL-WR1043ND - Making bootloader partition writable This package includes tools to read ( fw_printenv) and modify ( fw_setenv) U-Boot bootloader environment.

#U BOOT CONFIGURATION STEPS SERIAL#

Note that the header checksum is still verified.Īccessing U-Boot environment variables in Serial Console If set to n or no disables the checksum calculation over the complete image in the bootm command to trade speed for safety in the boot process. If the configuration option CONFIG_SILENT_CONSOLE has been enabled for your board, setting this variable to any value will suppress all console messages. TFTP server IP address needed for tftp command. U-Boot refuses to delete or overwrite this variable once it has been set.ĭefault load address for commands like tftp or loads This variable can be set only once (usually during manufacturing of the board).

#U BOOT CONFIGURATION STEPS MAC#

Name of the default image to load with TFTPĮthernet MAC address for first/only ethernet interface ( eth0 in Linux). Set this variable to -1 to disable autoboot. Be careful: depending on the contents of your bootcmd variable, this can prevent you from entering interactive commands again forever! Set this variable to 0 boot without delay.

During this time a countdown is printed, which can be interrupted by pressing any key. This command is only executed when the variable bootdelay is also defined!Īfter reset, U-Boot will wait this number of seconds before it executes the contents of the bootcmd variable. This variable defines a command string that is automatically executed when the initial countdown is not interrupted. The contents of this variable are passed to the Linux kernel as boot arguments (aka “command line”). If set to yes, an image loaded using the rarpb, bootp, dhcp, tftp, disk, or docb commands will be automatically started (by internally calling the bootm command).Ī decimal number that selects the console baudrate (in bps). If set to no (or any string beginning with 'n'), the rarpb, bootp or dhcp commands will perform only a configuration lookup from the BOOTP / DHCP server, but not try to load any image using TFTP. The location on the flash partition is predefined: package/uboot-ar71xx/files/include/configs/nbg460n.h for the Zyxel NBG 460N/550N/550NH. The environment variables are set up in a board specific file, e.g. The environment is usually at the end of the uboot partition. This flexibility is based on being able to easily change environment variables. One of the huge advantages of Das U-Boot is its ability for run time configuration. You can read and write these values when you are connected to the U-Boot console via Serial Port and also from the CLI once you booted OpenWrt. It stores some values like the IP address of the TFTP server (on your PC) to which the the TFTP client (part of U-Boot) will try to connect, etc. This can hardly be compared to NVRAM/TFFS-approach of other bootloaders.

Das U-Boot uses a small amount of space on the flash storage usually on the same partition it is stored on to store some important configuration parameters.