Parsing /proc/cpuinfo for model on Android and Aura

base/cpu.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/cpu.h"
 
 #include <string.h>
 
 #include <algorithm>
 
 #include "base/basictypes.h"
+#include "base/file_util.h"
 #include "build/build_config.h"
 
 #if defined(ARCH_CPU_X86_FAMILY)
 #if defined(_MSC_VER)
 #include <intrin.h>
 #include <immintrin.h>  // For _xgetbv()
 #endif
 #endif
 
 namespace base {
@@ skipping 129 matching lines @@
     }
     cpu_brand_.assign(cpu_string, cpu_string_ptr - cpu_string);
   }
 
   const int parameter_containing_non_stop_time_stamp_counter = 0x80000007;
   if (max_parameter >= parameter_containing_non_stop_time_stamp_counter) {
     __cpuid(cpu_info, parameter_containing_non_stop_time_stamp_counter);
     has_non_stop_time_stamp_counter_ = (cpu_info[3] & (1 << 8)) != 0;
   }
 #elif defined(ARCH_CPU_ARM_FAMILY)
-  // TODO(piman): Expand this. ARM has a CPUID register, but it's not available
-  // in user mode. /proc/cpuinfo has some information, but it's non standard,
-  // platform-specific, and not accessible from the sandbox.
-  // For some purposes, this first approximation is enough.
-  // crbug.com/313454
-  cpu_brand_.assign("ARM");
+#if defined(USE_AURA) || defined(OS_ANDROID)
+  const char kProcessorPrefix[] = "Processor";
+  std::string contents;
+  ReadFileToString(FilePath("/proc/cpuinfo"), &contents);

[Mark Mentovai, 2014/03/06 14:41:55]

How is this file formatted on ARM?

It’s probably too long to stick in a comment, but it’s helpful during review to
know what the entire file, and specifically the Processor line, actually looks
like.

[rptr, 2014/03/08 06:26:59]

This is how /proc/cpuinfo looks in Samsung Galaxy S2.

Processor       : ARMv7 Processor rev 1 (v7l)
processor       : 0
BogoMIPS        : 1592.52

processor       : 1
BogoMIPS        : 2388.78

Features        : swp half thumb fastmult vfp edsp neon vfpv3 tls
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x2
CPU part        : 0xc09
CPU revision    : 1

Hardware        : SMDK4210
Revision        : 000e
Serial          : *****

Same format is seen in all other android devices which i checked(Nexus S, Note
etc).

+  DCHECK(!contents.empty());
+  if (!contents.empty()) {
+    std::istringstream iss(contents);
+    std::string line;
+    while (std::getline(iss, line)) {
+      if (line.compare(0, strlen(kProcessorPrefix), kProcessorPrefix) == 0) {
+        size_t pos = line.find(": ");

[Mark Mentovai, 2014/03/07 15:19:18]

What if ": " was not found?

+        cpu_brand_.assign(line.substr(pos + 2));

[vivekg, 2014/03/07 11:59:52]

You probably need to break here to avoid processing further.

+      }
+    }
+  }
+#endif
 #endif
 }
 
 CPU::IntelMicroArchitecture CPU::GetIntelMicroArchitecture() const {
   if (has_avx()) return AVX;
   if (has_sse42()) return SSE42;
   if (has_sse41()) return SSE41;
   if (has_ssse3()) return SSSE3;
   if (has_sse3()) return SSE3;
   if (has_sse2()) return SSE2;
   if (has_sse()) return SSE;
   return PENTIUM;
 }
 
 }  // namespace base