Scanning for Hardware Capabilities - MotherBoard

Help & Support
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In order to “re-scan” for capabilities that are installed via PCI-bus, Linux offers the tool:

sudo  echo 1 > /sys/bus/pci/rescan

Is there a similar command allowing us to re-scan for MotherBoard “embedded” capabilities (not plugged into a PCI slot), like

  • on-board Ethernet interface & jack,
  • on-board WiFi capability,
  • on-board SATA socket capability,
  • on-board HDMI hardware,
  • etc.

which for whatever reason was not detected/reported at initial boot?


Same issue from a different perspective …

Is there a way to detect such “embedded” hardware if the BIOS did not detect it at initial boot time, but would detect it if a reboot was performed?

In other words, is there a mechanism which tells a MotherBoard’s BIOS to perform a “post-boot” hardware scan “refresh”? Or is the BIOS completely out of the loop, once the system has been booted up and running under a Linux OS?


P.S. This is a new take on a previously raised issue regarding my Network function being inoperable after boot, but for which a reboot usually fixes the problem. At that time, it was assessed that the issue is hardware degradation due to aging (heat/cold cycling stress-fracturing causing circuit break). I plan to try the above command at my next “no-internet” event, to see what transpires.

:slight_smile:

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There’s no single universal “rescan the BIOS” command, but the situation is a bit more nuanced than PCI vs onboard: most of what you listed (onboard SATA, onboard Ethernet, audio, even the integrated GPU driving your HDMI port) are actually chipset/PCH functions that show up on the PCI bus exactly like a discrete card, just wired to a fixed address instead of a slot, so /sys/bus/pci/rescan already covers most of them in principle (WiFi is the exception if it’s soldered via an internal USB header rather than M.2). The catch is that rescan only re-walks bus topology the firmware already enumerated and link-trained at boot; it doesn’t replay the low-level PCIe bring-up (link training, clock/power-rail sequencing) that BIOS performs during POST, so if a device never electrica

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