Add CROSS_DEBUG env variable to debug qemu-system

.travis.yml

@@ -7,7 +7,7 @@ sudo: required
 matrix:
  include:
  # Linux
- - env: TARGET=aarch64-unknown-linux-gnu CPP=1 DYLIB=1 STD=1 OPENSSL=0.5.5 RUN=1 RUNNERS="qemu-user qemu-system"
+ - env: TARGET=aarch64-unknown-linux-gnu CPP=1 DYLIB=1 STD=1 OPENSSL=0.5.5 RUN=1 RUNNERS="qemu-user qemu-system" CROSS_DEBUG=1
  - env: TARGET=arm-unknown-linux-gnueabi CPP=1 DYLIB=1 STD=1 OPENSSL=0.5.5 RUN=1
  - env: TARGET=arm-unknown-linux-musleabi STD=1 RUN=1
  - env: TARGET=armv7-unknown-linux-gnueabihf CPP=1 DYLIB=1 STD=1 OPENSSL=0.5.5 RUN=1

docker/linux-runner

@@ -2,6 +2,13 @@
 
 set -e
 
+LOG=/tmp/qemu.log
+LOCK=/tmp/qemu.lock
+
+if [ -n "$CROSS_DEBUG" ]; then
+ set -x
+fi
+
 # arch in the rust target
 arch=$1
 shift
@@ -23,7 +30,9 @@ case "$CROSS_RUNNER" in
  ;;
 esac
 
+# 8 is the max number of cpu supported by qemu-aarch64
 n=$(nproc)
+n=$(( n > 8 ? 8 : n ))
 memory=1G
 driver9p="virtio-9p-device"
 drivernet="virtio-net-device"
@@ -40,9 +49,7 @@ esac
 
  echo Booting QEMU virtual machine with $n cpus...
 
- touch /tmp/qemu.log
-
- qemu-system-$arch \
+ QEMU_CMD="qemu-system-$arch \
  -m $memory \
  -smp $n \
  -nographic \
@@ -53,17 +60,21 @@ esac
  -initrd /qemu/initrd.gz \
  $opt \
  -fsdev local,id=fs0,path=/target,security_model=mapped \
- -device $driver9p,fsdev=fs0,mount_tag=target 2>&1 >> /tmp/qemu.log &
+ -device $driver9p,fsdev=fs0,mount_tag=target"
+
+ touch $LOG
+ if [ -n "$CROSS_DEBUG" ]; then
+ ($QEMU_CMD 2>&1 | tee -a $LOG) &
+ else
+ $QEMU_CMD 2>&1 >> $LOG &
+ fi
 
- while read line; do
- if [[ "$line" == *"Not backgrounding"* ]]; then
- break
- fi
- done < <(tailf /tmp/qemu.log)
+ # wait for dropbear
+ tailf $LOG | grep -m1 "Not backgrounding" > /dev/null
 
  echo Booted in $(dbclient -K 1 -p 10022 -y -y root@localhost "cut -d' ' -f1 /proc/uptime") seconds
 
-) 200>/tmp/qemu.lock
+) 200>$LOCK
 
 exec dbclient \
  -t \

src/docker.rs

@@ -121,6 +121,10 @@ pub fn run(target: &Target,
  docker.args(&["-e", &format!("QEMU_STRACE={}", value)]);
  }
 
+ if let Some(value) = env::var("CROSS_DEBUG").ok() {
+ docker.args(&["-e", &format!("CROSS_DEBUG={}", value)]);
+ }
+
  let mut runner = target.default_runner();
 
  if let Some(toml) = toml {