barebox-state setup

Andreas Wilhelm andreas.wilhelm at emlix.com
Mon May 22 05:47:18 PDT 2017 

On 05/09/2017 10:26 AM, Andreas Wilhelm wrote:
> On 05/08/2017 02:18 PM, Sascha Hauer wrote:
>> On Fri, May 05, 2017 at 03:52:22PM +0200, Andreas Wilhelm wrote:
>>> On 05/03/2017 02:13 PM, Sascha Hauer wrote:
>>>> On Tue, May 02, 2017 at 03:24:10PM +0200, Andreas Wilhelm wrote:
>>>>> Hello,
>>>>>
>>>>> I am using barebox state to exchange data between barebox and linux. From barebox I can access and change the state without any problems. If I try to access the state using the barebox-state util included with dt-utils (v2017.03.0), I get the following error:
>>>>>
>>>>>> # barebox-state -g myvar
>>>>>> of_get_devicepath: no 'label' property found in /soc/aips-bus at 02000000/spba-bus at 02000000/ecspi at 02008000/m25p80 at 0
>>>>>> Cannot find backend path in /state
>>>>> This problem does not occur when using version 2016.08.0 of dt-utils. However, in this version I experienced an other problem. Even with backend-storage-type set to "circular" barebox attempted to storte data in "direct" mode:
>>>>>
>>>>>> WARNING, no stridesize given although we use a direct file
>>>>>> write. Starting in degraded mode
>>>>>> Failed to initialize desired amount of direct buckets, only 1 of 3
>>>>>> succeeded
>>>>> Furthermore changing the state from within barebox worked just fine, while changing it using dt-utils from within a booted linux didn't.
>>>>>
>>>>> The barebox state is stored in NOR-flash and configured in barebox as followed:
>>>>>
>>>>>> state: state {
>>>>>>     magic = <0x27031977>;
>>>>>>     compatible = "barebox,state";
>>>>>>     backend-type = "raw";
>>>>>>     backend = &flash, "partname:barebox-state";
>>>> Please use "backend = &barebox_state;" with a partition like this:
>>>>
>>>> barebox_state: partition at 0 {
>>>> 	reg = <0x0 0x40000>;
>>>> };
>>>>
>>>>> Within the linux kernel I use the following configuration
>>>> Note that barebox will rewrite the state node in the device tree passed
>>>> to Linux to make sure that both are consistent. You do not need to add a
>>>> state node to the Linux device tree manually. Unfortunately the
>>>> rewriting of the device node does not work correctly if you use the
>>>> "partname:" binding above in barebox.
>>>>
>>>> Sascha
>>>>
>>> Thanks for your fast reply.
>>>
>>> Removing the state definition from the linux device tree and changing
>>> the backend definition stopped barebox and dt-utils from complaining
>>> about a bad state backend. However, now I am facing a strange error.
>>>
>>> I am able to read and change the barebox state from within barebox and
>>> changes are reflected when reading from within barebox and linux. When
>>> changing the state using dt-utils, the change is persistent between
>>> reboots, but cannot be seen from within barebox.
>> First of all, what storage device are you using? Is it a real flash or
>> some EEPROM or NVRAM?
>>
>>> Example:
>>>
>>> // State myvar initialized with A by default
>>>
>>> state.myvar=B; state -s
>>> => Barebox: echo $state.myvar // myvar=B
>>> => Linux: barebox-state -g myvar // myvar=B
>>>
>>> barebox-state -s myvar=C
>>> => Barebox: echo $state.myvar // myvar=B
>>> => Linux: barebox-state -g myvar // myvar=C
>> This looks like a circular/noncircular mixup somewhere. Could you
>> hexdump the state partition (using the md command in barebox) to see if
>> the data is stored in circular or noncircular format? In circular format
>> you should see two copies of the same data directly after each other.
> It is stored in messed up circular-format:
>
> 00000000: 77 19 03 27 00 00 0c 00 6f c6 d5 7b 01 54 26 49    w..'....o..{.T&I
> 00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
> 00000020: 02 2d fa 14 28 00 00 00 77 19 03 27 00 00 0c 00    .-..(...w..'....
> 00000030: 0a a1 69 c3 9f 54 8c 85 00 00 00 00 00 00 00 00    ..i..T..........
> 00000040: 01 00 00 00 00 00 00 00 02 2d fa 14 28 00 00 00    .........-..(...
>> Also the output of barebox-state with -v might contain some useful
>> information.
>>
>> Sascha
>>
>>
> adding DT alias:ethernet0: stem=ethernet id=0 node=/soc/aips-bus at 02100000/ethernet at 02188000
> adding DT alias:can0: stem=can id=0 node=/soc/aips-bus at 02000000/flexcan at 02090000
> adding DT alias:can1: stem=can id=1 node=/soc/aips-bus at 02000000/flexcan at 02094000
> adding DT alias:gpio0: stem=gpio id=0 node=/soc/aips-bus at 02000000/gpio at 0209c000
> adding DT alias:gpio1: stem=gpio id=1 node=/soc/aips-bus at 02000000/gpio at 020a0000
> adding DT alias:gpio2: stem=gpio id=2 node=/soc/aips-bus at 02000000/gpio at 020a4000
> adding DT alias:gpio3: stem=gpio id=3 node=/soc/aips-bus at 02000000/gpio at 020a8000
> adding DT alias:gpio4: stem=gpio id=4 node=/soc/aips-bus at 02000000/gpio at 020ac000
> adding DT alias:gpio5: stem=gpio id=5 node=/soc/aips-bus at 02000000/gpio at 020b0000
> adding DT alias:gpio6: stem=gpio id=6 node=/soc/aips-bus at 02000000/gpio at 020b4000
> adding DT alias:i2c0: stem=i2c id=0 node=/soc/aips-bus at 02100000/i2c at 021a0000
> adding DT alias:i2c1: stem=i2c id=1 node=/soc/aips-bus at 02100000/i2c at 021a4000
> adding DT alias:i2c2: stem=i2c id=2 node=/soc/aips-bus at 02100000/i2c at 021a8000
> adding DT alias:mmc0: stem=mmc id=0 node=/soc/aips-bus at 02100000/usdhc at 02190000
> adding DT alias:mmc1: stem=mmc id=1 node=/soc/aips-bus at 02100000/usdhc at 02194000
> adding DT alias:mmc2: stem=mmc id=2 node=/soc/aips-bus at 02100000/usdhc at 02198000
> adding DT alias:mmc3: stem=mmc id=3 node=/soc/aips-bus at 02100000/usdhc at 0219c000
> adding DT alias:serial0: stem=serial id=0 node=/soc/aips-bus at 02000000/spba-bus at 02000000/serial at 02020000
> adding DT alias:serial1: stem=serial id=1 node=/soc/aips-bus at 02100000/serial at 021e8000
> adding DT alias:serial2: stem=serial id=2 node=/soc/aips-bus at 02100000/serial at 021ec000
> adding DT alias:serial3: stem=serial id=3 node=/soc/aips-bus at 02100000/serial at 021f0000
> adding DT alias:serial4: stem=serial id=4 node=/soc/aips-bus at 02100000/serial at 021f4000
> adding DT alias:spi0: stem=spi id=0 node=/soc/aips-bus at 02000000/spba-bus at 02000000/ecspi at 02008000
> adding DT alias:spi1: stem=spi id=1 node=/soc/aips-bus at 02000000/spba-bus at 02000000/ecspi at 0200c000
> adding DT alias:spi2: stem=spi id=2 node=/soc/aips-bus at 02000000/spba-bus at 02000000/ecspi at 02010000
> adding DT alias:spi3: stem=spi id=3 node=/soc/aips-bus at 02000000/spba-bus at 02000000/ecspi at 02014000
> adding DT alias:usbphy0: stem=usbphy id=0 node=/soc/aips-bus at 02000000/usbphy at 020c9000
> adding DT alias:usbphy1: stem=usbphy id=1 node=/soc/aips-bus at 02000000/usbphy at 020ca000
> adding DT alias:spi4: stem=spi id=4 node=/soc/aips-bus at 02000000/spba-bus at 02000000/ecspi at 02018000
> adding DT alias:ipu0: stem=ipu id=0 node=/soc/ipu at 02400000
> adding DT alias:rtc1: stem=rtc id=1 node=/soc/aips-bus at 02100000/i2c at 021a8000/da9062 at 58/rtc
> adding DT alias:rtc2: stem=rtc id=2 node=/soc/aips-bus at 02000000/snvs at 020cc000/snvs-rtc-lp at 34
> adding DT alias:rtc0: stem=rtc id=0 node=/soc/aips-bus at 02100000/i2c at 021a0000/rtc at 68
> adding DT alias:ipu1: stem=ipu id=1 node=/soc/ipu at 02800000
> found state node /state:
> state {
>         magic = <0x27031977>;
>         compatible = "barebox,state";
>         backend-type = "raw";
>         backend = <0x71>;
>         backend-storage-type = "circular";
>         #address-cells = <0x1>;
>         #size-cells = <0x1>;
>         myval1 {
>                 type = "enum32";
>                 reg = <0x0 0x4>;
>                 names = "N", "Y";
>         };
>         myval2 {
>                 type = "enum32";
>                 reg = <0x4 0x4>;
>                 names = "A", "B";
>         };
>         myval3 {
>                 type = "enum32";
>                 reg = <0x8 0x4>;
>                 names = "D", "T", "B";
>         };
> };
> state: Read state from -1204245760 length 0
> state: Read state from -1204245760 length 65536
> state: Read state from -1204245760 length 131072
> state: New state registered 'state'
> state: Read state from PEB 0 global offset 40 length 0
> state: Read state from -1204245760 length 40
> state: Read state from PEB 1 global offset 40 length 0
> state: Read state from -1204245760 length 65576
> state: Read state from PEB 2 global offset 40 length 0
> state: Read state from -1204245760 length 131112
> state: Using bucket 0 at 0x00000000
>
> Could this be caused by the definition of #address-cells and #size_cells?
>
> Best regards
> Andreas
Hi,

> First of all, what storage device are you using? Is it a real flash or
> some EEPROM or NVRAM?

we are using an SPI NOR flash Micron N25Q128A13ESE40F. Are there any known issues with this kind of chips? And what could cause such behavior as shown above?

Best regards
Andreas

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