diff options
Diffstat (limited to 'arch/x86/cpu/i386/cpu.c')
| -rw-r--r-- | arch/x86/cpu/i386/cpu.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/x86/cpu/i386/cpu.c b/arch/x86/cpu/i386/cpu.c index 8f342dd06e..7517b756f4 100644 --- a/arch/x86/cpu/i386/cpu.c +++ b/arch/x86/cpu/i386/cpu.c @@ -34,6 +34,10 @@ DECLARE_GLOBAL_DATA_PTR; +#define CPUID_FEATURE_PAE BIT(6) +#define CPUID_FEATURE_PSE36 BIT(17) +#define CPUID_FEAURE_HTT BIT(28) + /* * Constructor for a conventional segment GDT (or LDT) entry * This is a macro so it can be used in initialisers @@ -388,6 +392,25 @@ static void setup_identity(void) } } +static uint cpu_cpuid_extended_level(void) +{ + return cpuid_eax(0x80000000); +} + +int cpu_phys_address_size(void) +{ + if (!has_cpuid()) + return 32; + + if (cpu_cpuid_extended_level() >= 0x80000008) + return cpuid_eax(0x80000008) & 0xff; + + if (cpuid_edx(1) & (CPUID_FEATURE_PAE | CPUID_FEATURE_PSE36)) + return 36; + + return 32; +} + /* Don't allow PCI region 3 to use memory in the 2-4GB memory hole */ static void setup_pci_ram_top(void) { |