by Roderick W. Smith, rodsmith@rodsbooks.com
-Originally written: 3/14/2013; last Web page update: -1/16/2012, referencing rEFInd 0.6.5
+Originally written: 3/14/2012; last Web page update: +8/25/2013, referencing rEFInd 0.7.4
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@@ -26,49 +26,87 @@ href="mailto:rodsmith@rodsbooks.com">rodsmith@rodsbooks.comI've actually cut quite a few lines from this output; there are a total of 60 EFI: mem## lines on this computer. (Another of my computers has 148 such lines!) A BIOS-based computer will lack most or all of these lines, and certainly the EFI: mem## lines. I've heard of some BIOS-based computers that produce the final EFI Variables Facility line, though.
-One caveat exists to these tests: It's possible to boot Linux in EFI mode but disable the EFI features that create the /sys/firmware/efi directory and the copious EFI output in dmesg. This can happen because your kernel was compiled without EFI support or because you've added the noefi line to your existing BIOS boot loader configuration. To the best of my knowledge, no major Linux distribution ships with EFI support disabled in either of these ways, so chances are your tests won't mislead you to thinking you're using BIOS mode unless you've recompiled your kernel or deliberately added a noefi parameter to your boot loader configuration.
+One caveat exists to these tests: It's possible to boot Linux in EFI mode but disable the EFI features that create the /sys/firmware/efi directory and the copious EFI output in dmesg. This can happen because your kernel was compiled without EFI support or because you've added the noefi line to your existing BIOS boot loader configuration. Some of these features will also be absent if the efivars driver is not built into the kernel and is not loaded as a module. Typing modprobe efivars should load this module, so you might try that before concluding you've booted in BIOS mode. To the best of my knowledge, no major Linux distribution ships with EFI support disabled in any of these ways, so chances are your tests won't mislead you to thinking you're using BIOS mode unless you've recompiled your kernel or deliberately added a noefi parameter to your boot loader configuration.
Another way to identify your boot mode is to examine your partitions. Microsoft has tied use of the GUID Partition Table (GPT) to EFI booting. If you've booted from a GPT disk, then you must be using EFI, and if you've booted from a Master Boot Record (MBR) disk, you must have booted in BIOS mode. Therefore, you can check your partition table type as a proxy for your boot mode. To do this in Windows 7, follow these steps:
+The most reliable way I know of to identify your boot mode is to examine your partitions. Microsoft has tied use of the GUID Partition Table (GPT) to EFI booting. If you've booted from a GPT disk, then you must be using EFI, and if you've booted from a Master Boot Record (MBR) disk, you must have booted in BIOS mode. Therefore, you can check your partition table type as a proxy for your boot mode. To do this in Windows 7, follow these steps: