Real or Protected?
I've been using Linux for about 2 years now.
I began with MDK 9.2 and moved into Slackware 9.1 about year-ish ago.
One thing I've always wondered;
I came from a Windows world, like most of you probably did.
I've always wondered, is Linux a real or protected mode OS? Do these terms even apply for a monolithic kernel or is this just a Windows thing? If not, then can someone explain the difference, etc.?
A system running the Linux kernel runs in two states: kernel-space and user-space.
Many architectures, such as x86, have a handful of processor states, ranging from a 'real' mode with no protection (see: It does wtf you tell it to) to a 'protected' mode. On platforms such as x86 with more than two states, the two extremes are selected for kernel and user space. The kernel ( and all kernel modules ) run in kernel-space, which runs in 'real' mode. Userspace, on the other hand, runs in a protected mode which doesn't just arbitrarily execute code.