Revision as of 18:13, 23 September 2014 view source Columbus (talk \| contribs) 56 edits Added link to the ← Older edit		Revision as of 22:49, 13 November 2014 view source osdev>Augustl →‎How do I detect if the CPU is 64 bits ?: updating link to manuals Newer edit →
Line 25: ===How do I detect if the CPU is 64 bits ?=== After calling CPUID with EAX=0x80000001, all AMD64 compliant processors have the longmode-capable-bit turned on in the extended feature flags (bit 29) in EDX. There are also other bits required by long mode; you can check them out in the CPUID docs in the [http://support.amd.com/us/Processor_TechDocs/24594.pdf AMD general purpose instruction reference] (Link dead, the original author probably meant "AMD64 Architecture Programmer’s Manual Volume 3: General Purpose and System Instructions", found here: http://developer.amd.com/resources/documentation-articles/developer-guides-manuals/) ===How do I enable Long Mode ?===

X86-64: Difference between revisions