RE: Ubuntu 32-bit, 32-bit PAE, 64-bit Kernel Benchmarks

[Yuhong Bao]

> The way the 286 could access 16MB of memory was plain old segmentation, just in a different way than EMS did.
I mean different from the way 8086/8088 did, which was that the selector's base address was always the selector value itself shifted by 4 bit to get a 20-bit base address. The 286 and later supported this in their real mode (and virtual 8086 mode in 386 and later) for compatibility. But in their protected mode, the selector was looked up in the GDT/LDT to get the base address and length of the segment as well as protection attributes.

Yuhong Bao
 		 	   		  
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