Author Topic: A guide for the uEnv.txt file  (Read 24439 times)

ale92_

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A guide for the uEnv.txt file
« on: February 21, 2013, 06:34:20 am »
hi all,
is there a guide or a list of all the commands that i can use in the uEnv.txt file like the one used for the script.bin file (this one http://linux-sunxi.org/Fex_Guide)?

for example how to change the ip address or the resolution (i already know these ones and i am curious about all the other things i can do with the uEnv.txt file)

Offline patwood

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Re: A guide for the uEnv.txt file
« Reply #1 on: February 21, 2013, 11:58:13 pm »
There's this: http://www.kernel.org/doc/Documentation/kernel-parameters.txt which lists the generic kernel parameters.  There are a bunch that are specific to the Allwinner build (and perhaps other embedded builds) like mac_addr.  Don't know if these are all described in one place.

Offline lawrence

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Re: A guide for the uEnv.txt file
« Reply #2 on: February 22, 2013, 04:47:46 am »
the bootloader uses standard uboot code, so anything they support really.

uboot site documents here -

http://www.denx.de/wiki/DULG/Manual

Here for the scripting stuff - http://www.denx.de/wiki/view/DULG/UBootScripts

You'll need to check the source for the uboot implementation you are using to see whats supported.
I use theseven's one myself, as it has nand support.

https://github.com/TheSeven/u-boot-sunxi/

ale92_

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Re: A guide for the uEnv.txt file
« Reply #3 on: February 22, 2013, 12:17:23 pm »
thanks for the answers, i'll read those pages as soon as i can.
i was hoping for a more direct guide like the Fex one, maybe i'll do it if i figured this out.

ale92_

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Re: A guide for the uEnv.txt file
« Reply #4 on: February 25, 2013, 05:05:23 am »
after i couple of days of searching that's what i found.
in the u-boot documentation i read that the commands i'm looking for are called: "Env Variables", so i looked for this in the u-boot git (the official one) and this is the list i found.
fw_env.c
Code: [Select]
bootargs
bootcmd
ramboot
nfsboot
bootdelay
baudrate
loads_echo
ethaddr
eth1addr
eth2addr
eth3addr
eth4addr
eth5addr
ethprime
ipaddr
serverip
autoload
rootpath
gatewayip
netmask
hostname
bootfile
loadaddr
preboot
clocks_in_mhz
pcidelay
arch
cpu
board
vendor
soc

i guess these are standard commands, i still don't understand where people get commands like : vncinstall ipv4 or disp.screen0_output_mode or hdmi.audio that's look like "board specific" (or "soc specific") commands.

can you help me?
« Last Edit: February 25, 2013, 08:32:24 am by ale92_ »

Offline lawrence

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Re: A guide for the uEnv.txt file
« Reply #5 on: February 25, 2013, 08:24:12 am »
You're confusing kernel with bootloader.

 disp.screen0_output_mode is a kernel parameter.

You can check passed parameters by looking at:

cat /proc/cmdline 

after boot.

This has a list of kernel parameters:

http://www.kernel.org/doc/Documentation/kernel-parameters.txt

Note that the drivers in the sunxi kernel may or may not support all the parameters.
I don't think there is a list of parameters available unfortunately, so you'll need to check the driver code to see whats allowable or implemented.

Offline patwood

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Re: A guide for the uEnv.txt file
« Reply #6 on: February 25, 2013, 11:07:39 am »
The dot parameters (e.g., disp.xxx) are module (aka driver) parameters and will be specific to each module.