| From: Karen Lewellen via talk <talk@gtalug.org> | Hi Stewart, | Your comment is no doubt true. however, if one is building a setup for a | simple accommodation, given for Linux and some other systems the older | distros, or the 32 bit ones might actually be better. | Depends on the goal does it not? | Consider the freedos project. | www.freedos.org | Just a thought, Right. So far, all x86-64 processors can also run 32-bit programs. But UEFI firmware comes in 32-bit or 64-bit. So the almost-nonexistent 32-bit OS that runs under UEFI is pretty much out of luck. But almost all 32-bit OSes (like FreeDOS) booted in MBR / "legacy mode", not UEFI. They work fine when booted this way. But some locked-down devices don't support "legacy mode". This will surely become common for all device in the future but it doesn't seem to be yet. For example, the Lenovo ThinkCentre devices do support legacy mode booting. Details: Examples of 32-bit x86 UEFI systems: - the very first Intel-based Macs. Their Intel Core Duo processor was 32-bit only. But their UEFI implementations were screwy anyway. Avoid. Apple shortly went to 64-bit with the Core 2 Duo. - some x86 machines were designed to compete with ARM devices (on price and capabilities) and not eat into the market for higher-priced X86 devices. Through licensing terms, Intel and Microsoft attempted this anti-competitive feat. These devices used Intel x86 Atom chips that could run 64-bit code but had 32-bit UEFI-only firmware (no legacy). The intention was to limit them to 32-bit Windows. Sneaky Linux folks managed to run 64-bit kernels and userland on top of 32-bit UEFI. I have a few of these devices, all getting old since Intel threw in the towel on this fight many years ago. Example devices: Dell Venue 8 pro tablet, Asus Transformer T100 TAF. Enabling legacy mode: This can be tricky. You have to go into the firmware setup screen. This is usually called the BIOS setup screen but that is a misnomer: under UEFI there is no BIOS, only firmware. The actual setting changes required are odd and idiosyncratic -- different for different machines. Here are some hints: - Secure Boot and MBR booting don't co-exist well. Turn off Secure Boot. - UEFI booting is the opposite of "Legacy Booting". Select legacy booting. - enable "CSM" (Compatibility Support Module). This is the thing in UEFI firmware that emulates BIOS system calls. Some firmware requires you to enable this to even see the other required options. - the boot order screen may talk about UEFI and Legacy targets. Make sure you enable Legacy. Finding all this stuff may seem like the classic game "Adventure". I'm currently having trouble booting FreeDOS on a computer I just got. I haven't figured it out but I haven't given up.