fw/target: add hostid to TargetInfo

Add hostid entry, as reported by busybox's hostid applet, to TargetInfo.
This is intended to be a "unique 32-bit identifier for the current
machine". In practice, it may not be set, or may be generated from
something like an IP address, so may not be unique. However, if set, it
is still likely to be more unique than kernel/os version so may be worth
recording.

wa/framework/target/info.py

@@ -171,6 +171,9 @@ def get_target_info(target):
         # best effort -- debugfs might not be mounted
         pass
 
+    hostid_string = target.execute('{} hostid'.format(target.busybox)).strip()
+    info.hostid = int(hostid_string, 16)
+
     for i, name in enumerate(target.cpuinfo.cpu_names):
         cpu = CpuInfo()
         cpu.id = i
@@ -215,6 +218,7 @@ class TargetInfo(object):
         instance.cpus = [CpuInfo.from_pod(c) for c in pod['cpus']]
         instance.os = pod['os']
         instance.os_version = pod['os_version']
+        instance.hostid = pod['hostid']
         instance.abi = pod['abi']
         instance.is_rooted = pod['is_rooted']
         instance.kernel_version = kernel_version_from_pod(pod)
@@ -233,6 +237,7 @@ class TargetInfo(object):
         self.cpus = []
         self.os = None
         self.os_version = None
+        self.hostid = None
         self.abi = None
         self.is_rooted = None
         self.kernel_version = None
@@ -246,6 +251,7 @@ class TargetInfo(object):
         pod['cpus'] = [c.to_pod() for c in self.cpus]
         pod['os'] = self.os
         pod['os_version'] = self.os_version
+        pod['hostid'] = self.hostid
         pod['abi'] = self.abi
         pod['is_rooted'] = self.is_rooted
         pod['kernel_release'] = self.kernel_version.release