[coreboot] Fwd: Ethernet problem in x200

[Nico Huber]

On 28.03.2017 01:39, Denis 'GNUtoo' Carikli wrote:
> On Mon, 27 Mar 2017 16:14:53 +0200
> Zoran Stojsavljevic <zoran.stojsavljevic at gmail.com> wrote:
> 
>> [user at localhost projects]$ cat dmesg.txt | grep 00:19.0
>> [    0.151652] pci 0000:00:19.0: *[8086:294c*] type 00 class 0x020000
>> [    0.151694] pci 0000:00:19.0: reg 0x10: [mem 0xe1600000-0xe161ffff]
>> [    0.151707] pci 0000:00:19.0: reg 0x14: [mem 0xe1624000-0xe1624fff]
>> [    0.151721] pci 0000:00:19.0: reg 0x18: [io  0x3000-0x301f]
>> [    0.151802] pci 0000:00:19.0: PME# supported from D0 D3hot D3cold
>> [    1.489719] e1000e 0000:00:19.0: Interrupt Throttling Rate
>> (ints/sec) set to dynamic conservative mode
>> [    1.611526] e1000e 0000:00:19.0: The NVM Checksum Is Not Valid
>> *[    1.635873] e1000e: probe of 0000:00:19.0 failed with error -5*
> The Lenovo Thinkpad X200 uses a GM45 chipset. This chipset supports
> different ways of booting:
> (1) Having a boot fimrware occupy all the flash chip, if you do that the
>     Ethernet will not work, according to the datasheet.
> (2) Having a boot firmware with the management engine firmware.
> (3) Having a boot firmware without the management engine firmware.
> 
> It is strongly advised to do (3) and follow the corresponding coreboot
> documentation.

Strongly advised by who? In which scenario? Under which assumptions?

> To get a working Ethernet with (3) you need to set a
> valid mac address:
> In the installation documentation, you are expected to use ich9gen,
> however if you use it this way:
>> $ ./ich9gen
> It will not produce a valid MAC address. You must instead do something
> like that, and replace <A-VALID-MAC-ADDRESS> by a valid MAC address:
>> $ ./ich9gen --macaddress <A-VALID-MAC-ADDRESS>
> To find such MAC address, you have several options:
> - Look if it can be found on a sticker on the bottom of your laptop.
> - Reflash the original flash content and get it with:
>> $ ifconfig -a
> or:
>> ip link

Pew, thanks for reminding me, that we have this in our wiki.

> 
> == Side note ==
> According to the wikipedia article on MAC Address[1], the 3 bytes on
> the left correspond to a vendor/organisation.
> So I got a valid MAC address with the methods mentioned above, and only
> kept the 3 bytes on the left, and tested that MAC address:
>> 00:1f:16:00:00:00
> And it worked on my Lenovo Thinkpad X200.
> To use that MAC address, just use:
>> $ ./ich9gen --macaddress 
> 
> It might be possible that all addresses between 00:1f:16:00:00:00 and
> 00:1f:16:FF:FF:FF work, but I didn't test that.

If you read that article, you might learn that any but the broadcast ad-
dress should work, as long as it's unique on the local network segment.
Also, that your address claims to be globally unique. Which might not be
the best idea.

Nico

> 
> References:
> -----------
> [1]https://en.wikipedia.org/wiki/MAC_address#Address_details
> 
> Denis.