.. | .. |
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6 | 6 | Enable passing additional variables for synthetic uevents that |
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7 | 7 | are generated by writing /sys/.../uevent file. |
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8 | 8 | |
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9 | | - Recognized extended format is ACTION [UUID [KEY=VALUE ...]. |
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| 9 | + Recognized extended format is:: |
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10 | 10 | |
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11 | | - The ACTION is compulsory - it is the name of the uevent action |
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12 | | - ("add", "change", "remove"). There is no change compared to |
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13 | | - previous functionality here. The rest of the extended format |
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14 | | - is optional. |
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| 11 | + ACTION [UUID [KEY=VALUE ...] |
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| 12 | + |
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| 13 | + The ACTION is compulsory - it is the name of the uevent |
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| 14 | + action (``add``, ``change``, ``remove``). There is no change |
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| 15 | + compared to previous functionality here. The rest of the |
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| 16 | + extended format is optional. |
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15 | 17 | |
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16 | 18 | You need to pass UUID first before any KEY=VALUE pairs. |
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17 | | - The UUID must be in "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" |
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| 19 | + The UUID must be in ``xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`` |
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18 | 20 | format where 'x' is a hex digit. The UUID is considered to be |
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19 | 21 | a transaction identifier so it's possible to use the same UUID |
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20 | 22 | value for one or more synthetic uevents in which case we |
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21 | 23 | logically group these uevents together for any userspace |
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22 | 24 | listeners. The UUID value appears in uevent as |
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23 | | - "SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" environment |
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| 25 | + ``SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`` environment |
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24 | 26 | variable. |
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25 | 27 | |
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26 | 28 | If UUID is not passed in, the generated synthetic uevent gains |
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27 | | - "SYNTH_UUID=0" environment variable automatically. |
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| 29 | + ``SYNTH_UUID=0`` environment variable automatically. |
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28 | 30 | |
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29 | 31 | The KEY=VALUE pairs can contain alphanumeric characters only. |
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| 32 | + |
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30 | 33 | It's possible to define zero or more pairs - each pair is then |
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31 | 34 | delimited by a space character ' '. Each pair appears in |
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32 | | - synthetic uevent as "SYNTH_ARG_KEY=VALUE". That means the KEY |
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33 | | - name gains "SYNTH_ARG_" prefix to avoid possible collisions |
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| 35 | + synthetic uevent as ``SYNTH_ARG_KEY=VALUE``. That means the KEY |
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| 36 | + name gains ``SYNTH_ARG_`` prefix to avoid possible collisions |
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34 | 37 | with existing variables. |
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35 | 38 | |
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36 | | - Example of valid sequence written to the uevent file: |
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| 39 | + Example of valid sequence written to the uevent file:: |
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37 | 40 | |
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38 | 41 | add fe4d7c9d-b8c6-4a70-9ef1-3d8a58d18eed A=1 B=abc |
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39 | 42 | |
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40 | | - This generates synthetic uevent including these variables: |
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| 43 | + This generates synthetic uevent including these variables:: |
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41 | 44 | |
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42 | 45 | ACTION=add |
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43 | 46 | SYNTH_ARG_A=1 |
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44 | 47 | SYNTH_ARG_B=abc |
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45 | 48 | SYNTH_UUID=fe4d7c9d-b8c6-4a70-9ef1-3d8a58d18eed |
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| 49 | + |
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46 | 50 | Users: |
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47 | 51 | udev, userspace tools generating synthetic uevents |
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