Ubuntu
udev package

  1. Bug #48547
  2. Comment #4

Comment 4 for bug 48547

Revision history for this message
Paul Sladen (sladen) wrote :

This module searches BIOS space for a 4-byte signature and then does a call to this address with:

  ax = 0x9610
  bl = 0x35
  bh = 0x00 (switch off), 0x01 (switch on), 0x02 (check if enabled in BIOS)

and states that it was produced from reverse engineering 'wbutton.sys' for a 'Fujitsu Siemens Amilo M 7400' laptop. Hopefully this BIOS call might actually be exposed through ACPI instead.