detecting no USB device quickly
- From: phil-news-nospam@xxxxxxxx
- Date: 4 May 2007 19:38:16 GMT
When I boot a kernel on a system with a USB drive attached, there is some
time delay before that drive is available. That time happens to be after
the /init program in my initramfs image gets started. I don't have any
problem with waiting for the USB drive to become available. What I do have
a problem with is doing that waiting when there is no USB drive at all.
The goal is to make this init program specifically look around at drive
contents for what it needs to do. For example a drive with a specific key
on it (perhaps as simple as which filesystem has the latest date on it)
will become the root file system. The USB drive might be plugged in as a
rescue disk on occaision.
Is there any way to detect, right when /init starts, whether there is some
USB device plugged in that is not yet completely registered (as opposed to
there being a USB controller without anything plugged in). It does not
even have to be known to be a storage device, yet. I just want to make
this /init program skip the delay if there are no USB devices at all at
boot time.
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| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / spamtrap-2007-05-04-1247@xxxxxxxx |
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