[PATCH] defconfig: espressobin: enable NET_RANDOM_ETHADDR

[Tom Rini]

On Tue, Sep 08, 2020 at 10:14:15AM +0200, Andre Heider wrote:
> On 08/09/2020 09:42, Pali Rohár wrote:
> > On Tuesday 08 September 2020 08:35:00 Andre Heider wrote:
> > > The hardware does not provide a MAC address. Enable this so that
> > > network access works with just the default environment.
> > 
> > Well, this is not fully truth as MAC address is stored in SPI, just in
> > non-standard format, in U-Boot env stored in env partition and it is
> > hard to use outside of U-Boot, plus easy to erase / overwrite / lost.
> 
> True, but updating the bootloader usually implies wiping the env, so it's
> very easy to lose it.

It most certainly should NOT wipe out the existing environment, it
should be using the same environment location as before.

> > I'm not a big fan of this change. This looks like a workaround / hack
> > for boards where MAC address was erased (e.g. by broken U-Boot distro
> > scripts) or for early boards where MAC address was not written at all
> > (as I was told).
> > 
> > And on these boards this patch would cause that U-Boot would see on
> > every boot different MAC address. This would cause another mess in
> > network for U-Boot netboot as DHCP/TFTP server would see for one board
> > every time different MAC address.
> > 
> > Is not really better to instruct user how to fix board where e.g. broken
> > distro scripts erased MAC address? We have already paragraph in
> > README.marvell about it.
> > 
> > Also this change affects "default" defconfig value. And based on above
> > arguments I do not think that this change should be enabled by default.
> > 
> > I understand that for some situations it may be useful (e.g. mass board
> > reparation process via netboot), but as this is config option, users in
> > such situation can enable this option manually.
> > 
> > I think that for default behavior is not provide network access in
> > U-Boot if for some reasons factory permanent MAC address was removed.
> > User can easier and faster detect this issue and fix it.
> 
> It can be argued both ways I guess. If this option wouldn't make sense it
> wouldn't exist.
> 
> Out of the box working network access is probably what most users care
> about.
> 
> Changing this default means that you need to build the whole firmware
> yourself, and let's face it: building it for this board is a total
> clusterfuck. Most users will just download a binary. I don't care too much
> for this patch, but I would consider what fits most users.
> 
> Right now most users will probably run the downstream binaries provided by
> armbian, and as you know, that even has single hardcoded MAC, used for all
> boards. So this would already be an improvement ;)

Note that when CONFIG_NET_RANDOM_ETHADDR is set, we only use a random
MAC address when we haven't found one either on the hardware or
environment.  It also prints a warning that you are using a random MAC,
so if it's documented on how to recover the real MAC a user should see
that warning and fix it.

-- 
Tom
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