Skip to content
Open
Changes from 1 commit
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion src/content/chapters/1-the-basics.mdx
Original file line number Diff line number Diff line change
Expand Up @@ -72,7 +72,7 @@ It's time to leap through our first rabbit hole into a land filled with syscalls

## Two Rings to Rule Them All

The *mode* (sometimes called privilege level or ring) a processor is in controls what it's allowed to do. Modern architectures have at least two options: kernel/supervisor mode and user mode. While an architecture might support more than two modes, only kernel mode and user mode are commonly used these days.
The *mode* (sometimes called privilege level or ring) controls what a processor it's allowed to do. Modern architectures have at least two options: kernel/supervisor mode and user mode. While an architecture might support more than two modes, only kernel mode and user mode are commonly used these days.

In kernel mode, anything goes: the CPU is allowed to execute any supported instruction and access any memory. In user mode, only a subset of instructions is allowed, I/O and memory access is limited, and many CPU settings are locked. Generally, the kernel and drivers run in kernel mode while applications run in user mode.

Expand Down