[Arm-dev] Lies! Doesn't work on Raspberry Pi 3

Robert Moskowitz rgm at htt-consult.com
Fri Sep 8 12:15:47 UTC 2017


Johnny,

Excellent write up.


On 09/08/2017 08:07 AM, Johnny Hughes wrote:
> On 09/01/2017 10:27 PM, Binary Buddha wrote:
>> ifconfig -a I get the normal expected output for eth0 and lo "UP,BROADCAST,RUNNING,MULTICAST”. But, I never receive a DHCP address. No packet info because it’s not connecting. As mentioned before, not even the lights on the ethernet port blink.
>>
>> I’m on the RPi 3 Model B V1.2. Is the version the same? Any chance you clean install with the same version of Centos that’s posted to see if it still works for you?
>>
> I have a RPi 3, Model B V 1.2 ,  Copyright Raspberry Pi 2015
>
> I grabbed this image:
>
> http://mirror.centos.org/altarch/7/isos/armhfp/CentOS-Userland-7-armv7hl-Minimal-1611-RaspberryPi3.img.xz
>
> I put a San Disk 64GB Extreme Plus card into my CentOS-7 x86_64 laptop
> card reader .. it showed up as /dev/mmcblk0 and I made sure I unmounted it.
>
> I used this command to push the image to the card:
>
> xzcat ./CentOS-Userland-7-armv7hl-Minimal-1611-RaspberryPi3.img.xz |
> sudo dd of=/dev/mmcblk0 status=progress bs=8M
>
> I then did this to make sure the dd finished:
>
> sudo sync
>
> I then wanted to go ahead and bump up the 'root partition' size to fill
> the card, so I opened up the card using fdisk:
>
> sudo fdisk /dev/mmcblk0
>
> It shows this as the main Linux partition:
>
> /dev/mmcblk0p3         2074624     6268927     2097152   83  Linux
>
> I want to make the 3rd partition use all space .. so, I deleted
> partition 3 (d command) and recreated it (n command, the primary (p) and
> 3rd partition (3)) starting at the same sector (2074624) ending at the
> last sector on the card (124735487).  now it looks like this:
>
> /dev/mmcblk0p3         2074624   124735487    61330432   83  Linux
>
> So partition 3 went from 2 GB to 60 GB
>
> Now I will use the w command to exit fdisk.
>
> Took the card out of my laptop .. put it into the RPi 3
>
> Hooked up NIC to my network and an HDMI monitor to the HDMI port and
> turned it on to boot:
>
> This is what appears on the console:
>
> https://people.centos.org/hughesjr/rpi3-boot.jpg
>
> (you can see that the NIC port turned on, 100Mbps, the lights are
> working normally on the port)
>
> Plugged in the keyboard .. logged on as root.
>
> I have an IP address:
>
> [root at centos-rpi3 ~]# ip a
> 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
>      link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
>      inet 127.0.0.1/8 scope host lo
>         valid_lft forever preferred_lft forever
>      inet6 ::1/128 scope host
>         valid_lft forever preferred_lft forever
> 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
> state UP qlen 1000
>      link/ether b8:27:eb:ef:55:fd brd ff:ff:ff:ff:ff:ff
>      inet 192.168.0.41/24 brd 192.168.0.255 scope global dynamic eth0
>         valid_lft 2589sec preferred_lft 2589sec
>      inet6 ::ba27:ebff:feef:55fd/64 scope global mngtmpaddr dynamic
>         valid_lft 3600sec preferred_lft 3600sec
>      inet6 fe80::ba27:ebff:feef:55fd/64 scope link
>         valid_lft forever preferred_lft forever
>
>
> So, the image works fine.
>
> If you are not getting an ip address and if the lights are not working,
> then:
>
> 1)  You have a network cable issue
> 2)  You have a hardware issue on either the NIC port on the RPi or the
> NIC Port on your switch/hub/router.
> 3)  You have some kind of routing issue between your dhcp server and the
> RPi3 where the packets can not traverse .. BUT, not likely, you said
> that the lights don't work.
> 4)  You have a software issue, where your dhcp server does not recognize
> the dhcp request from this device .. again, not likely if the lights are
> not working.
>
> I then ran the command:  resize2fs /dev/mmcblk0p3
>
> (to resize my root partition that I grew with fdisk from my laptop)
>
> rebooted
>
> Everything works fine.
>
> SO .. the image does work with RPi3 and a standard gbit netgear hub and
> my normal internet provider's gbit router as the dhcp server.
>
> I do think that you said the lights are not working .. if that is the
> case, then there is LIKELY something wrong with something physical
> between the two ports or the cable.  I suppose it could also be a power
> supply issue for the unit.
>
> Can you use a different OS image on a different SDCARD to boot and get
> connectivity with the same setup?
>
> Did you check the sha256sum of your image before you burned it?
>
> Thanks,
> Johnny Hughes
>
>
>
>
>
>
>
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> Arm-dev mailing list
> Arm-dev at centos.org
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