[OE-core] [PATCH 1/1] runqemu: improve auto-detection of rootfs filenames

[Scott Garman]

This refactors the way rootfs filenames are auto-detected when you
run the runqemu script without an explicit rootfs filename argument.
It allows the script to use rootfs files generated by hob, and when
there are mutliple rootfs files to choose from, it will pick the
most recently created one.

Fixes [YOCTO #1437].

Signed-off-by: Scott Garman <scott.a.garman at intel.com>
---
 scripts/runqemu |   35 +++++++++++++++--------------------
 1 files changed, 15 insertions(+), 20 deletions(-)

diff --git a/scripts/runqemu b/scripts/runqemu
index 74938f7..8f44c0d 100755
--- a/scripts/runqemu
+++ b/scripts/runqemu
@@ -241,31 +241,24 @@ machine2=`echo $MACHINE | tr 'a-z' 'A-Z' | sed 's/-/_/'`
 # Defaults used when these vars need to be inferred
 QEMUX86_DEFAULT_KERNEL=bzImage-qemux86.bin
 QEMUX86_DEFAULT_FSTYPE=ext3
-QEMUX86_DEFAULT_ROOTFS="core-image-sato-sdk core-image-sato core-image-lsb core-image-basic core-image-minimal"
 
 QEMUX86_64_DEFAULT_KERNEL=bzImage-qemux86-64.bin
 QEMUX86_64_DEFAULT_FSTYPE=ext3
-QEMUX86_64_DEFAULT_ROOTFS="core-image-sato-sdk core-image-sato core-image-lsb core-image-basic core-image-minimal"
 
 QEMUARM_DEFAULT_KERNEL=zImage-qemuarm.bin
 QEMUARM_DEFAULT_FSTYPE=ext3
-QEMUARM_DEFAULT_ROOTFS="core-image-sato-sdk core-image-sato core-image-lsb core-image-basic core-image-minimal"
 
 QEMUMIPS_DEFAULT_KERNEL=vmlinux-qemumips.bin
 QEMUMIPS_DEFAULT_FSTYPE=ext3
-QEMUMIPS_DEFAULT_ROOTFS="core-image-sato-sdk core-image-sato core-image-lsb core-image-basic core-image-minimal"
 
 QEMUPPC_DEFAULT_KERNEL=zImage-qemuppc.bin
 QEMUPPC_DEFAULT_FSTYPE=ext3
-QEMUPPC_DEFAULT_ROOTFS="core-image-sato-sdk core-image-sato core-image-lsb core-image-basic core-image-minimal"
 
 AKITA_DEFAULT_KERNEL=zImage-akita.bin
 AKITA_DEFAULT_FSTYPE=jffs2
-AKITA_DEFAULT_ROOTFS="core-image-sato"
 
 SPITZ_DEFAULT_KERNEL=zImage-spitz.bin
 SPITZ_DEFAULT_FSTYPE=ext3
-SPITZ_DEFAULT_ROOTFS="core-image-sato"
 
 setup_tmpdir() {
     if [ -z "$TMPDIR" ]; then
@@ -302,26 +295,28 @@ setup_sysroot() {
     fi 
 }
 
-# Locate a rootfs image based on defaults defined above
+# Locate a rootfs image to boot which matches our expected
+# machine and fstype. 
 findimage() {
     where=$1
     machine=$2
     extension=$3
-    names=$4
 
-    for name in $names; do
-        fullname=$where/$name-$machine.$extension
-        if [ -e "$fullname" ]; then
-            ROOTFS=$fullname
+    # Sort rootfs candidates by modification time - the most
+    # recently created one is the one we most likely want to boot.
+    filenames=`ls -t $where/*core-image*$machine.$extension 2>/dev/null | xargs`
+    for name in $filenames; do
+        if [[ "$name" =~ core-image-sato-sdk ||
+              "$name" =~ core-image-sato     ||
+              "$name" =~ core-image-lsb      ||
+              "$name" =~ core-image-basic    ||
+              "$name" =~ core-image-minimal ]]; then
+            ROOTFS=$name
             return
-        fi
-    done
-
-    echo "Couldn't find image in $where. Attempted image names were:"
-    for name in $names; do
-        echo $name-$machine.$extension
+        fi	
     done
 
+    echo "Couldn't find a $machine rootfs image in $where."
     exit 1
 }
 
@@ -378,7 +373,7 @@ if [ -z "$ROOTFS" ]; then
     setup_tmpdir
     T=$TMPDIR/deploy/images
     eval rootfs_list=\$${machine2}_DEFAULT_ROOTFS
-    findimage $T $MACHINE $FSTYPE "$rootfs_list"
+    findimage $T $MACHINE $FSTYPE
 
     if [ -z "$ROOTFS" ]; then
         echo "Error: Unable to determine default rootfs for MACHINE [$MACHINE]"
-- 
1.7.1