[HN Gopher] Using Device Tree Overlays, Example on BeagleBone Bo...
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       Using Device Tree Overlays, Example on BeagleBone Boards
        
       Author : pabs3
       Score  : 42 points
       Date   : 2022-02-15 04:56 UTC (18 hours ago)
        
 (HTM) web link (bootlin.com)
 (TXT) w3m dump (bootlin.com)
        
       | rgrs wrote:
       | Can I remove an applied overlay?
       | 
       | Something like,
       | 
       | - apply overlay
       | 
       | - use the device
       | 
       | - unbind device & driver
       | 
       | - remove applied overlay
        
         | ghostpepper wrote:
         | Yep, believe the remove flag to dtoverlay is -r
        
       | ktownsend wrote:
       | The same concept is also used in smaller embedded systems, like
       | Zephyr RTOS:
       | https://docs.zephyrproject.org/latest/guides/dts/index.html
       | 
       | Useful video if you're interested in how DT applies to Zephyr,
       | such as defining I2C sensors available on your board target:
       | https://www.youtube.com/watch?v=sWaxQyIgEBY
        
         | koz1000 wrote:
         | I wouldn't call it the same concept. Zephyr uses the Devicetree
         | format to create headers and configure the compilation of the
         | kernel, but userspace code has _zero_ visibility into whatever
         | was set up in the devicetree file.
         | 
         | Zephyr is chock full of these creature comforts to make Linux
         | developers feel at home but only deliver 50% of the usability.
         | I went back to FreeRTOS.
        
           | pantalaimon wrote:
           | I mean on the small ROM of MCUs you don't usually want to
           | keep the device tree around, so it's just sensible that it
           | gets turned into macros and is not accessible at run time.
           | 
           | Given that FreeRTOS does not deal with hardware at all, I
           | don't see how it is a comparison.
        
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       (page generated 2022-02-15 23:02 UTC)