From: Mike Looijmans <mike.looijmans@topic.nl>
To: u-boot@lists.denx.de
Subject: [U-Boot] ethernet: ROM MAC address vs env variable MAC address
Date: Tue, 14 Nov 2017 10:31:56 +0100 [thread overview]
Message-ID: <45c912c9-ce5a-4ee0-326a-e1dadce04b65@topic.nl> (raw)
In-Reply-To: <20171113194902.3A0A0120504@gemini.denx.de>
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On 13-11-17 20:49, Wolfgang Denk wrote:
> Dear Prabhakar,
>
> In message <HE1PR04MB12410876E4BA09FC9CD7800C97560@HE1PR04MB1241.eurprd04.prod.outlook.com> you wrote:
>>
>> Why ROM MAC address getting overwritten by environment env MAC address.
>
> Because in U-Boot we give the user the freedom to do what he
> needs/wants to do. Usually the environment value gets initialized
> from the value in the ROM, so there is no difference anyway. But if
> the user wants a specific setting, he can change it.
>
>> MAC address is something unique and assigned to a particular device. So one should never change its MAC address.
>
> U-Boot follows good old UNIX style here:
>
> "UNIX was not designed to stop you from doing stupid things, because
> that would also stop you from doing clever things." - Doug Gwyn
Many board manufacturers "assign" this unique MAC address by printing it on a
sticker and sticking that on the board somewhere. It's pretty darn hard to
read a printed sticker in software, so we have to revert to solutions that
actually work.
In the "clever things" department, protocols like IPv6 merrily broadcast your
MAC address across gateways on the big bad internet, so if you value your
privacy, you'll appreciate the possibility to change your MAC address at will.
Kind regards,
Mike Looijmans
System Expert
TOPIC Products
Materiaalweg 4, NL-5681 RJ Best
Postbus 440, NL-5680 AK Best
Telefoon: +31 (0) 499 33 69 79
E-mail: mike.looijmans at topicproducts.com
Website: www.topicproducts.com
Please consider the environment before printing this e-mail
prev parent reply other threads:[~2017-11-14 9:31 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-08 12:02 [U-Boot] ethernet: ROM MAC address vs env variable MAC address Prabhakar Kushwaha
2017-11-09 10:14 ` Lukasz Majewski
2017-11-13 19:49 ` Wolfgang Denk
2017-11-14 9:31 ` Mike Looijmans [this message]
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