On Mon, Mar 29, 2021 at 12:58 AM Willy Tarreau <w...@1wt.eu> wrote: > > On Sun, Mar 28, 2021 at 11:14:05PM +0300, Andy Shevchenko wrote: > > On Sunday, March 28, 2021, Willy Tarreau <w...@1wt.eu> wrote: > > > > > Hi Thomas, > > > > > > On Sun, Mar 28, 2021 at 03:07:24AM +0200, Thomas Gleixner wrote: > > > > On Sun, Mar 28 2021 at 00:25, Willy Tarreau wrote: > > > > > On Sat, Mar 27, 2021 at 10:13:22PM +0100, Mateusz Jonczyk wrote: > > > > > FWIW I tested on my ASUS 1025C which runs on an Atom N2600 forced to > > > > > 32-bit. I had already tried in the past but wanted to give it a try > > > > > again in case I'd have missed anything. Sadly it didn't work, I'm > > > > > still getting the "requires an x86-64 CPU" message. > > > > > > > > > > Given these machines were really cheap, I've always suspected that > > > > > they > > > > > employ cheaper, low-grade CPUs, possibly having been subject to > > > > > reduced > > > > > tests where x86_64-specific parts were not even verified and might be > > > > > defective. This may explain why they forcefully disable long mode > > > there, > > > > > but that's just speculation. > > > > > > > > There are some of these '32bit only' CPUs out there in the wild which > > > > actually support long mode. Some of them even do not have the long mode > > > > CPUID bit fused out. > > > > > > Yes, I'm aware of this as well. We might even have talked to the same > > > "victim" :-) > > > > > > > But whether it works is a different story: > > > > > > > > - If the CPUID bit is on, then the chance is high, but it runs out of > > > > spec (guarantee wise) > > > > > > > > - If it's off is still might work by some definition of work as they > > > > might have fused off more or there are actual defects in some 64bit > > > > only area which are irrelevant when in 32bit mode. > > > > > > > > Even if it could work perfectly fine, the BIOS/SMM/ucode can prevent > > > > switching to long mode. > > > > > > > > It's a lost cause. > > > > > > I agree. While I bought this netbook to have a 64-bit CPU and was > > > extremely > > > disappointed, > > > > > > Where did you get an idea that it had 64-bit SoC from? > > It's an N2600, and I bought this laptop because N2600 supports 64-bit > (and do have another mini-itx motherboard at work with the same CPU > on it working pretty well in 64-bit): > > > https://ark.intel.com/content/www/us/en/ark/products/58916/intel-atom-processor-n2600-1m-cache-1-6-ghz.html
Wow, TIL. :-) > > Atom Based 64-bit ones are Bay Trail, Cherry Trail, Tangier (Merrifield), > > Anniedale (Moorefield) and all based on Skylake family (Apollo Lake, > > Broxton, Gemini Lake, ...). > > Well, to be honest, I've never been able to remind (nor sort) all these > totally crazy names. The day someone gives me a mnemotechnic hint to > remind them and their ordering, that will make me reconsider them. For > now they're all "something lake", and I find it particularly difficult > to map them to SKUs. It took me a few years to be on trend with those names, that's how Wikipedia [1] helps. [1]: https://en.wikipedia.org/wiki/List_of_Intel_Atom_microprocessors -- With Best Regards, Andy Shevchenko
