Laen
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Pi Zero W identifying as "B Rev 2"

Thu Mar 23, 2017 9:17 pm

Hi,

I recently purchased some Pi Zero W's from Adafruit, and I'm having trouble with one of them. When I boot it up, there's no wlan0, and the "Revision" in /proc/cpuinfo us 000f, which I believe indicates "Model B Rev 2". The same memory card in another PiZeroW works properly.

The bottom silkscreen on the board says It's a Pi Zero W v1.1.

Is this something that can be fixed with a firmware update, or should I return it to Adafruit?

Thanks,
-Laen
OSH Park

Laen
Posts: 9
Joined: Thu Mar 23, 2017 9:02 pm

Re: Pi Zero W identifying as "B Rev 2"

Thu Mar 23, 2017 11:27 pm

I went through all 10 of the Pi Zero W's I purchased, and 5 of them are "bad".

I've tried running "rpi-update" on a bad one, and that didn't fix it.

Here's /proc/cpuinfo on a "bad" one:

Code: Select all

processor	: 0
model name	: ARMv6-compatible processor rev 7 (v6l)
BogoMIPS	: 697.95
Features	: half thumb fastmult vfp edsp java tls 
CPU implementer	: 0x41
CPU architecture: 7
CPU variant	: 0x0
CPU part	: 0xb76
CPU revision	: 7

Hardware	: BCM2835
Revision	: 000f
Serial		: 000000000a59fd89
Here it is on a good one:

Code: Select all

processor	: 0
model name	: ARMv6-compatible processor rev 7 (v6l)
BogoMIPS	: 697.95
Features	: half thumb fastmult vfp edsp java tls 
CPU implementer	: 0x41
CPU architecture: 7
CPU variant	: 0x0
CPU part	: 0xb76
CPU revision	: 7

Hardware	: BCM2708
Revision	: 9000c1
Serial		: 0000000040a07aef
"Hardware" and "Revision" are different.

arraybytes
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Re: Pi Zero W identifying as "B Rev 2"

Fri Mar 24, 2017 2:31 am

did you get the W's form the same source?
did you buy them all at the same time?

Laen
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Re: Pi Zero W identifying as "B Rev 2"

Fri Mar 24, 2017 3:36 am

Yes. All 10 came from Adafruit in the same order.

Physically, the non-working ones look exactly like the working ones. Chip markings are all the same, they all say "Pi Zero W 1.1" on the bottom silkscreen.

Laen
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Re: Pi Zero W identifying as "B Rev 2"

Fri Mar 24, 2017 6:18 am

Okay, getting closer.. It looks like the wrong device tree is being selected by uBoot on the "bad" ones. I don't yet know how uBoot chooses which one to select.

Bad:

Code: Select all

001399.502: Read command line from file 'cmdline.txt'
dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait quiet splash plymouth.ignore-serial-consoles modules-load=dwc2,g_ether
001710.700: Loading 'kernel.img' to 0x8000 size 0x3f1128
001710.750: No kernel trailer (run mkknlimg to fix) - assuming DT-capable
001714.426: Loading 'bcm2708-rpi-b.dtb' to 0x3f9128 size 0x36ba
001774.871: dtparam: audio=on
001791.638: Loaded overlay 'dwc2'
002719.211: Device tree loaded to 0x1bfec400 (size 0x3bd7)
002720.480: gpioman: gpioman_get_pin_num: pin SDCARD_CONTROL_POWER not defined
003761.568: vchiq_core: vchiq_init_state: slot_zero = 0x5b880000, is_master = 1
003766.307: hdmi: HDMI:hdmi_get_state is deprecated, use hdmi_get_display_state instead
003771.899: TV service:host side not connected, dropping notification 0x00000002, 0x00000002, 0x00000004
Good:

Code: Select all

001769.777: *** Restart logging
001772.896: Read command line from file 'cmdline.txt'
dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait quiet splash plymouth.ignore-serial-consoles modules-load=dwc2,g_ether
002050.004: Loading 'kernel.img' to 0x8000 size 0x3f1128
002053.688: No kernel trailer (run mkknlimg to fix) - assuming DT-capable
002056.197: Loading 'bcm2708-rpi-0-w.dtb' to 0x3f9128 size 0x39ba
002120.073: dtparam: audio=on
002137.952: Loaded overlay 'dwc2'
003164.265: Device tree loaded to 0x17fec100 (size 0x3eff)
003165.646: gpioman: gpioman_get_pin_num: pin SDCARD_CONTROL_POWER not defined
004196.051: vchiq_core: vchiq_init_state: slot_zero = 0x57880000, is_master = 1
004200.771: hdmi: HDMI:hdmi_get_state is deprecated, use hdmi_get_display_state instead

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Paul Webster
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Re: Pi Zero W identifying as "B Rev 2"

Fri Mar 24, 2017 7:12 am

Laen wrote:Yes. All 10 came from Adafruit in the same order.
Interesting side issue .... looks like the 1 Zero-W per order was relaxed.

Martin Frezman
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Re: Pi Zero W identifying as "B Rev 2"

Fri Mar 24, 2017 8:18 am

Paul Webster wrote:
Laen wrote:Yes. All 10 came from Adafruit in the same order.
Interesting side issue .... looks like the 1 Zero-W per order was relaxed.
Not necessarily. My understanding is that the "1 per" limit is only on purchases of "Just the Zero". If you buy some kind of kit that includes the Zero, then you can buy as many as you want. Adafruit, in particular, sells lots of different such kits. I'm guessing that's what OP did.
If this post appears in the wrong forums category, my apologies.

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DougieLawson
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Re: Pi Zero W identifying as "B Rev 2"

Fri Mar 24, 2017 8:57 am

Are you sure your SDCard is loaded with the right version of Raspbian or NOOBS to support your shiny new hardware?

Adafruit are notorious for shipping SDCards loaded with pre-historic versions of NOOBS that aren't updated for the new hardware they ship them with. (Someone should give them a slap for doing that.)

Try reformatting your SDCards and loading them up with 2017-03-02 Raspbian of NOOBS 2.3.
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gregeric
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Re: Pi Zero W identifying as "B Rev 2"

Fri Mar 24, 2017 9:41 am

Sounds like the revision hasn't been written to OTP at the factory. See viewtopic.php?f=43&t=160611

Laen
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Re: Pi Zero W identifying as "B Rev 2"

Fri Mar 24, 2017 2:10 pm

DougieLawson wrote:Are you sure your SDCard is loaded with the right version of Raspbian or NOOBS to support your shiny new hardware?

Try reformatting your SDCards and loading them up with 2017-03-02 Raspbian of NOOBS 2.3.
Yes. I've been doing all my testing with 2017-03-02.

Laen
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Re: Pi Zero W identifying as "B Rev 2"

Fri Mar 24, 2017 2:14 pm

gregeric wrote:Sounds like the revision hasn't been written to OTP at the factory. See viewtopic.php?f=43&t=160611
Ah ha! Yes. That's it.

jamesh
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Re: Pi Zero W identifying as "B Rev 2"

Fri Mar 24, 2017 3:55 pm

Can you try adding

force_board_rev=0x9000c0

to the /boot/config.txt file?

Might help, might not.

See this github thread..

https://github.com/raspberrypi/firmware/issues/758
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Laen
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Joined: Thu Mar 23, 2017 9:02 pm

Re: Pi Zero W identifying as "B Rev 2"

Tue Apr 04, 2017 10:54 pm

Adding "force_board_rev=0x9000c0" to the config.txt file resulting in a non-booting system.

Is flashing the OTP something I can do on my own, or should I return these units to my vendor?

jamesh
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Re: Pi Zero W identifying as "B Rev 2"

Wed Apr 05, 2017 9:19 am

It needs to be RMA'd. Looks like a badly programmed device.
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wesleyfurr
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Re: Pi Zero W identifying as "B Rev 2"

Mon Jul 24, 2017 1:34 am

Just a quick note to anyone else who runs into this...I've got a Zero W that does the same thing. The symptom I first noticed was that the power/activity LED did not light up. Second was that wifi would not work and wlan0 did not appear under ifconfig.

Forcing board to 0x9000c0 causes a blinking LED (four slow, four fast, repeat) and no boot.

Forcing it to the plain Zero board ID of 0x900093 makes the power LED work properly. I have not tested a camera to see if that works. Still no dice on the wireless, but at least it could be used as a plain Zero...and presumably the camera connector would work...

The Zero W I'm having trouble with was purchased at the St. Louis Microcenter store less than two weeks ago. Unfortunately, I live on the east coast...so it looks like I got a $10 Pi Zero...unless I can make it to the Washington DC area store within the return window...

johnlane
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Re: Pi Zero W identifying as "B Rev 2"

Tue Sep 19, 2017 10:32 am

For anyone else reading this thread after seeing the wrong hardware reported in `/proc/cpuinfo`, I saw this on a Zero and I believe it is due to the kernel version.

Kernel 4.4 reports BCM2708

Code: Select all

$ cat /proc/cpuinfo
Hardware        : BCM2708
$ uname -a
Linux foo 4.4.48-2-ARCH #1 Mon Feb 13 19:53:47 MST 2017 armv6l GNU/Linux
Kernel 4.9 reports BCM2385

Code: Select all

$ cat /proc/cpuinfo
Hardware        : BCM2385
$ uname -a
Linux bar 4.9.33-1-ARCH #1 SMP Sun Jun 18 02:10:01 UTC 2017 armv6l GNU/Linux
I tried two sdcards with different builds of ArchLinux on two different Pi Zeros.

I also tried the same two sdcards on an early (revision 2) model B with the same result. So it isn't a hardware nor zero-specific problem, but more of a a kernel problem.
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DougieLawson
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Re: Pi Zero W identifying as "B Rev 2"

Tue Sep 19, 2017 10:51 am

It's not a kernel problem, it's a choice by the upstream kernel developers to label ALL raspberries as BCM2835 devices. It's been in 4.9 kernels forever.

The software that uses that for device ID needs to change.

It's more reliable to parse the virtual file /sys/firmware/devicetree/base/model.
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Martin Frezman
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Re: Pi Zero W identifying as "B Rev 2"

Tue Sep 19, 2017 11:06 am

DougieLawson wrote:
Tue Sep 19, 2017 10:51 am
It's more reliable to parse the virtual file /sys/firmware/devicetree/base/model.
Provided that file exists. On one of my machines, I get:

Code: Select all

$  nl /sys/firmware/devicetree/base/model
nl: /sys/firmware/devicetree/base/model: No such file or directory
$
If this post appears in the wrong forums category, my apologies.

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HawaiianPi
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Re: Pi Zero W identifying as "B Rev 2"

Sun Apr 29, 2018 1:54 am

gregeric wrote:
Fri Mar 24, 2017 9:41 am
Sounds like the revision hasn't been written to OTP at the factory. See viewtopic.php?f=43&t=160611
Interesting. I wonder how many of these slipped through the cracks? It seems like this could be at least one cause for WiFi problems that a small number of people seem to be having. Mine shows the correct info.

~ $ cat /sys/firmware/devicetree/base/model;echo
Image Raspberry Pi Zero W Rev 1.1 Image
My mind is like a browser. 27 tabs are open, 9 aren't responding,
lots of pop-ups...and where is that annoying music coming from?

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davidcoton
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Re: Pi Zero W identifying as "B Rev 2"

Sun Apr 29, 2018 11:02 am

HawaiianPi wrote:
Sun Apr 29, 2018 1:54 am
Image Raspberry Pi Zero W Rev 1.1 Image
:shock: That is so very wrong. It is not a Banana Pi. :roll:
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jamesh
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Re: Pi Zero W identifying as "B Rev 2"

Sun Apr 29, 2018 1:12 pm

HawaiianPi wrote:
Sun Apr 29, 2018 1:54 am
gregeric wrote:
Fri Mar 24, 2017 9:41 am
Sounds like the revision hasn't been written to OTP at the factory. See viewtopic.php?f=43&t=160611
Interesting. I wonder how many of these slipped through the cracks? It seems like this could be at least one cause for WiFi problems that a small number of people seem to be having. Mine shows the correct info.

~ $ cat /sys/firmware/devicetree/base/model;echo
Image Raspberry Pi Zero W Rev 1.1 Image
It does happen occasionally, and each time it does the reports are fed back to the factory, in an effort to stop it happening.
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