Package: live-boot
Severity: wishlist
Tags: patch
If a preferred medium (device or medium type) is given with the
live-media parameter then waiting for the timeout to expire before
scaning for these devices is not necessary. Just pick the device as soon
as it appears. If a criterium would match several devices the outcome is
undefined anyway. So choosing the first one is good enough.
If no removable or removable-usb device is found after the timeout
expires, just boot any live medium available instead of panicing.
The second change makes it possible to have a non-wirteable (ISO)
live-image with the default boot parameter set to
live-media=removable-usb for machines that can't boot directly from USB
devices. If a live medium on an USB device is present it'll be
preferred, but the ISO will also boot without an USB device.
The attached patch implements a solution to both of these issues.
Gaudenz
-- System Information:
Debian Release: 7.0
APT prefers testing
APT policy: (800, 'testing'), (700, 'unstable'), (50, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 3.2.0-4-amd64 (SMP w/2 CPU cores)
Locale: LANG=de_CH.UTF-8, LC_CTYPE=de_CH.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
>From 50de32e9d644b09225937c0968dd7fb0095ab1d1 Mon Sep 17 00:00:00 2001
From: Gaudenz Steinlin <gaud...@debian.org>
Date: Thu, 17 Jan 2013 16:45:27 +0100
Subject: [PATCH] Immediately detect medium from live-media parameter
If a preferred medium (device or medium type) is given with the
live-media parameter then waiting for the timeout to expire before
scaning for these devices is not necessary. Just pick the device as soon
as it appears. If a criterium would match several devices the outcome is
undefined anyway. So choosing the first one is good enough.
If no removable or removable-usb device is found after the timeout
expires, just boot any live medium available instead of panicing.
---
scripts/boot/9990-misc-helpers.sh | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)
diff --git a/scripts/boot/9990-misc-helpers.sh b/scripts/boot/9990-misc-helpers.sh
index 888eeaf..1341972 100755
--- a/scripts/boot/9990-misc-helpers.sh
+++ b/scripts/boot/9990-misc-helpers.sh
@@ -259,16 +259,10 @@ find_livefs ()
{
timeout="${1}"
- # don't start autodetection before timeout has expired
- if [ -n "${LIVE_MEDIA_TIMEOUT}" ]
- then
- if [ "${timeout}" -lt "${LIVE_MEDIA_TIMEOUT}" ]
- then
- return 1
- fi
- fi
-
- # first look at the one specified in the command line
+ # first look at the one specified in the command line This is OK
+ # before the timeout has expired, if more than one device matches the
+ # criteria the outcome is undefined anyway, so we can pick the first
+ # one that appears.
case "${LIVE_MEDIA}" in
removable-usb)
for sysblock in $(removable_usb_dev "sys")
@@ -281,7 +275,6 @@ find_livefs ()
fi
done
done
- return 1
;;
removable)
@@ -295,7 +288,6 @@ find_livefs ()
fi
done
done
- return 1
;;
*)
@@ -309,7 +301,16 @@ find_livefs ()
;;
esac
- # or do the scan of block devices
+ # don't start autodetection before timeout has expired
+ if [ -n "${LIVE_MEDIA_TIMEOUT}" ]
+ then
+ if [ "${timeout}" -lt "${LIVE_MEDIA_TIMEOUT}" ]
+ then
+ return 1
+ fi
+ fi
+
+ # autodetection of live media
# prefer removable devices over non-removable devices, so scan them first
devices_to_scan="$(removable_dev 'sys') $(non_removable_dev 'sys')"
--
1.7.10.4
