ejolson
Posts: 6040
Joined: Tue Mar 18, 2014 11:47 am

Re: Which components of a Pi have unique serial numbers..?

Tue Oct 25, 2016 5:29 am

W. H. Heydt wrote:which makes it a case of creating a new thread on the same topic as a closed thread, and that is a violation of Forum rules.
Where is the forum rule written which says no new thread can be started on the same topic as a closed thread?

Is it possible that rule and others have been replaced by the single rule "be good to each other"?

jdb
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 2468
Joined: Thu Jul 11, 2013 2:37 pm

Re: Which components of a Pi have unique serial numbers..?

Tue Oct 25, 2016 10:08 am

ejolson wrote:
W. H. Heydt wrote:which makes it a case of creating a new thread on the same topic as a closed thread, and that is a violation of Forum rules.
Where is the forum rule written which says no new thread can be started on the same topic as a closed thread?

Is it possible that rule and others have been replaced by the single rule "be good to each other"?
Or the corollary "don't annoy the mods". We know who's sockpuppeting, so please don't stir the pot with speculation.

Regarding OP vs unique serial numbers:
- The SMSC LAN chip has a random MAC. We set it on boot to be the Pi-specific OUI+trailing bits of the SoC serial number.
- The BCM wifi/bt chip has a MAC address embedded in NVRAM. It's set to the same as the Ethernet MAC address (derived from SoC serial number) but with the lower 24 bits inverted compared to the Ethernet MAC address.
- Any USB device is "supposed" to have a unique serial number. Of course, virtually no manufacturer of commodity devices actually implements programming of this number so most often it's zero or a value shared with every other device made in a particular month. The only devices I've seen that reliably have unique serials are FTDI interface devices.
- Any 1-wire device attached to the Pi has a 64-bit random serial number as this method is used to identify devices on the bus.
- SD cards are supposed to have "random" serial numbers. In general these follow the same rigorousness of application as USB devices - but the big manufacturers (that produce flash and controller together) usually implement it properly.

Of course, the SD controller is a MCU in reality - with a command space that's vendor-defined thus pretty much anything can be stored in it. The thing I'd trust the least in any Pi system would be the SD card. You can even hack them if you know how.
https://www.bunniestudios.com/blog/?p=3554
Rockets are loud.
https://astro-pi.org

mikerr
Posts: 2826
Joined: Thu Jan 12, 2012 12:46 pm
Location: UK
Contact: Website

Re: Which components of a Pi have unique serial numbers..?

Tue Oct 25, 2016 11:34 am

If anyone wants to have a practical play or log all your serials, here's a quick guide

Only the first is really pi specific, the rest will work on all linux systems

Pi serial:

Code: Select all

cat /proc/cpuinfo | grep Serial
Serial : 000000007d2bacd7

MAC Addresses for ethernet & wifi:

Code: Select all

ifconfig |grep HWaddr
eth0 Link encap:Ethernet HWaddr b8:27:eb:2b:ac:d7
wlan0 Link encap:Ethernet HWaddr b8:27:eb:7e:f9:82

Bluetooth MAC

Code: Select all

 echo exit |bluetoothctl |grep Controller
[NEW] Controller B8:27:EB:81:06:7D raspberrypi [default]

SD card serial:

Code: Select all

udevadm info -a -n /dev/mmcblk0 | grep -i serial
ATTRS{serial}=="0x2124178d"

HDD or flashdrive

Code: Select all

udevadm info  -n /dev/sda | grep -i serial
E: ID_SERIAL=Lexar_JD_FireFly_AA04015300017918-0:0
Android app - Raspi Card Imager - download and image SD cards - No PC required !

W. H. Heydt
Posts: 13636
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Which components of a Pi have unique serial numbers..?

Tue Oct 25, 2016 1:44 pm

ejolson wrote:
W. H. Heydt wrote:which makes it a case of creating a new thread on the same topic as a closed thread, and that is a violation of Forum rules.
Where is the forum rule written which says no new thread can be started on the same topic as a closed thread?

Is it possible that rule and others have been replaced by the single rule "be good to each other"?
I derive it from threads being closed because they are new threads on old, closed, topics. Most often on rancorous topics. We will see how long this one runs...

mutley
Posts: 61
Joined: Sat Jan 02, 2016 8:06 pm

Re: Which components of a Pi have unique serial numbers..?

Tue Oct 25, 2016 8:29 pm

broe23 wrote:
mutley wrote: <snip>
This is ignoring anything printed on the outside of a component, I have no idea about that.
Nice that you are playing third party again. How many profiles did you make up this week?
More unfounded accusations, I've been a member for close to a year, please grow up.
search.php?author_id=171591&sr=posts
memberlist.php?mode=viewprofile&u=171591

broe23
Posts: 902
Joined: Thu Jan 28, 2016 9:35 pm
Location: Central IL
Contact: Website

Re: Which components of a Pi have unique serial numbers..?

Tue Oct 25, 2016 10:16 pm

ejolson wrote:
W. H. Heydt wrote:which makes it a case of creating a new thread on the same topic as a closed thread, and that is a violation of Forum rules.
Where is the forum rule written which says no new thread can be started on the same topic as a closed thread?

Is it possible that rule and others have been replaced by the single rule "be good to each other"?
It is because Liz got tired of having to drop everything she has to do at her office at the Foundation, to take care of a bunch of childish posts.

She has stated in the rules that as other boards state, that if a thread is locked, do not post asking why or try and restart it again with a new thread topic.
Ren: Now listen, Cadet. I've got a job for you. See this button? Ren: Don't touch it! It's the History Eraser button, you fool! Stimpy: So what'll happen? Ren: That's just it. We don't know. Maybe something bad, maybe something good.

W. H. Heydt
Posts: 13636
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Which components of a Pi have unique serial numbers..?

Tue Oct 25, 2016 10:37 pm

broe23 wrote:
ejolson wrote:
W. H. Heydt wrote:which makes it a case of creating a new thread on the same topic as a closed thread, and that is a violation of Forum rules.
Where is the forum rule written which says no new thread can be started on the same topic as a closed thread?

Is it possible that rule and others have been replaced by the single rule "be good to each other"?
It is because Liz got tired of having to drop everything she has to do at her office at the Foundation, to take care of a bunch of childish posts.

She has stated in the rules that as other boards state, that if a thread is locked, do not post asking why or try and restart it again with a new thread topic.
Forum rules (speaking generally, not specifically about *this* set of Forums) are kind of like Mitchner's fictional description of the problem with translating a particular Biblical injunction into Hawaiian. Too many people will attempt to go by the letter of the "law" and ignore the intent if it doesn't suit their desires.

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