4 ms·
I'm not sure that abstraction is even in the OS. I think its on the memory controller itself. The OS reads from the memory controller.
by jacurtis 3y ago
I'm not sure that abstraction is even in the OS. I think its on the memory controller itself. The OS reads from the memory controller.
- yjftsjthsd-h 3y agoI'm pretty sure it's more of a cooperative arrangement; the OS writes the configuration that the MMU uses, thereby imposing its rules on programs.
- vacuity 3y agoThe OS controls the MMU.
- yjftsjthsd-h 3y agoI mean, sure, that's also a valid description. If we're to be precise, at least on x86 the OS sets up a global descriptor table[0] and then uses the LGDT instruction to tell the CPU to use it[1], and LGDT is a privileged instruction so only the OS (kernel) can do that. [0] https://wiki.osdev.org/Global_Descriptor_Table https://wiki.osdev.org/Global_Descriptor_Table [1] https://wiki.osdev.org/GDT_Tutorial#Telling_the_CPU_Where_the_Table_Is https://wiki.osdev.org/GDT_Tutorial#Telling_the_CPU_Where_th...