1 files changed, 20 insertions, 0 deletions
diff --git a/src/arch/x86/lib/cpu.c b/src/arch/x86/lib/cpu.c
index 3732ae296e..aaa0a16185 100644
--- a/src/arch/x86/lib/cpu.c
+++ b/src/arch/x86/lib/cpu.c
@@ -131,6 +131,26 @@ static const char *cpu_vendor_name(int vendor)
 	return name;
 }
 
+static int cpu_cpuid_extended_level(void)
+{
+	return cpuid_eax(0x80000000);
+}
+
+#define CPUID_FEATURE_PAE (1 << 6)
+#define CPUID_FEATURE_PSE36 (1 << 17)
+
+int cpu_phys_address_size(void)
+{
+	if (!(have_cpuid_p()))
+		return 32;
+
+	if (cpu_cpuid_extended_level() > 0x80000008)
+		return cpuid_eax(0x80000008) & 0xff;
+
+	if (cpuid_eax(1) & (CPUID_FEATURE_PAE | CPUID_FEATURE_PSE36))
+		return 36;
+	return 32;
+}
 static void identify_cpu(struct device *cpu)
 {
 	char vendor_name[16];