From f2c51bc81d2aa618b29ddbeaae5ac1c5308821f0 Mon Sep 17 00:00:00 2001 From: Alex Auvolat Date: Mon, 9 Feb 2015 17:39:41 +0100 Subject: Reorganize all. --- src/kernel/include/gdt.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) create mode 100644 src/kernel/include/gdt.h (limited to 'src/kernel/include/gdt.h') diff --git a/src/kernel/include/gdt.h b/src/kernel/include/gdt.h new file mode 100644 index 0000000..a62d0db --- /dev/null +++ b/src/kernel/include/gdt.h @@ -0,0 +1,17 @@ +#pragma once + +#include +#include + +/* The GDT is one of the x86's descriptor tables. It is used for memory segmentation. + Here, we don't use segmentation to separate processes from one another (this is done with paging). + We only use segmentation to make the difference between kernel mode (ring 3) and user mode (ring 0) */ + +void gdt_init(); + +#define K_CODE_SEGMENT 0x08 +#define K_DATA_SEGMENT 0x10 +#define U_CODE_SEGMENT 0x18 +#define U_DATA_SEGMENT 0x20 + +/* vim: set ts=4 sw=4 tw=0 noet :*/ -- cgit v1.2.3