probe: generic_cpu: read 'cpu architecture'
For ARMv8, 64bit kernel, it seems that the /proc/cpuinfo won't report
"model name". The "CPU architecture" field seems to be supported. So a
workaround might be reading this as backup plan.
BUG=b:123880691
TEST=None
Change-Id: I9bd8685c2b6bf384b8094c69b2e133fc4a91079c
Reviewed-on: https://chromium-review.googlesource.com/1480753
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Wei-Han Chen <stimim@chromium.org>
Reviewed-by: Fei Shao <fshao@chromium.org>
diff --git a/py/probe/functions/generic_cpu.py b/py/probe/functions/generic_cpu.py
index 59d9350..3e534b3 100644
--- a/py/probe/functions/generic_cpu.py
+++ b/py/probe/functions/generic_cpu.py
@@ -57,10 +57,11 @@
@classmethod
def _ProbeArm(cls):
- # For platforms like arm, it sometimes gives the model name in 'Processor',
- # and sometimes in 'model name'. But they all give something like 'ARMv7
- # Processor rev 4 (v71)' only. So to uniquely identify an ARM CPU, we should
- # use the 'Hardware' field.
+ # For ARM platform, ChromeOS kernel has/had special code to expose fields
+ # like 'model name' or 'Processor' and 'Hardware' field. However, this
+ # doesn't seem to be available in ARMv8 (and probably all future versions).
+ # In this case, we will use 'CPU architecture' to identify the ARM version.
+
CPU_INFO_FILE = '/proc/cpuinfo'
with open(CPU_INFO_FILE, 'r') as f:
cpuinfo = f.read()
@@ -68,13 +69,28 @@
def _SearchCPUInfo(regex, name):
matched = re.search(regex, cpuinfo, re.MULTILINE)
if matched is None:
- logging.error('Unable to find "%s" field in %s.', name, CPU_INFO_FILE)
+ logging.warning('Unable to find "%s" field in %s.', name, CPU_INFO_FILE)
return 'unknown'
return matched.group(1)
+ # For ARMv7, model and hardware should be available.
model = _SearchCPUInfo(r'^(?:Processor|model name)\s*: (.*)$', 'model')
hardware = _SearchCPUInfo(r'^Hardware\s*: (.*)$', 'hardware')
+
+ # For ARMv8, there is no model nor hardware, we use 'CPU architecture' as
+ # backup plan. For an ARM device project (reference board and all follower
+ # devices), all SKUs should be using same ARM CPU. So we don't really need
+ # detail information. In the future, we can consider adding other "CPU .*"
+ # fields into model name if we think they are important.
+ architecture = _SearchCPUInfo(r'^CPU architecture\s*: (\d+)$',
+ 'architecture')
+ if model.strip() == 'unknown' and architecture != 'unknown':
+ model = 'ARMv' + architecture.strip()
+ else:
+ logging.error('Unable to construct "model" of ARM CPU')
+
cores = process_utils.CheckOutput('nproc', shell=True, log=True)
+
return {
'model': model.strip(),
'cores': cores.strip(),
