#4349 NORM Never A: Improve startup speed

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#4349: Improve startup speed
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  Reporter:  wmb at firmworks.com  |       Owner:  cscott        
      Type:  defect             |      Status:  new           
  Priority:  normal             |   Milestone:  Never Assigned
 Component:  distro             |     Version:                
Resolution:                     |    Keywords:                
  Verified:  0                  |  
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Comment(by wmb at firmworks.com):

 Summarizing a related discussion about udev speedup possibilities:

 a) Hard-link some things that are currently modules.  The current (as of
 617) list of modules loaded during startup is: cs5535_gpio, psmouse,
 serio_raw, ieee80211_crypt, ieee80211, libertas, mousedev, i2c_dev.

 b) Create the portions of /dev/ that correspond to built-in devices
 "manually" (e.g. in hard-coded script) instead of dynamically via udev
 (keeping in mind that /dev is on a RAM filesystem).

 c) Make a simplified udev ruleset that only handles USB devices, omitting
 devices that cannot possibly be attached to XO (e.g. random PCI and ISA
 devices).  Note that the udev upstream has rulesets for several distros,
 most of which are quite simple compared to our current set).

 d) To ensure that our image still works with qemu, we may want to have
 separate scripts for real OLPC hardware and QEMU, choosing between the two
 either at run time or installation time.

 e) Modify modprobe so that it doesn't open the .ko files R/W (which is
 only needed for supporting the --force option, which we don't want to
 use), and thus does not break COW links.  Or maybe use insmod manually for
 the modules that we know we want to use, or maybe both.

-- 
Ticket URL: <https://dev.laptop.org/ticket/4349#comment:2>
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