Task State Segment. More...

Collaboration diagram for TSS:

Functions
void	tss_init (gdt_entry_t *gdt)
	Initializes the TSS. More...

void	tss_set_stack (uint32_t stack_pointer)
	Sets the TSS's kernel stack which is used to handle interrupts. More...

void	tss_load ()
	Loads the TSS into the TR register. More...

Variables
static tss_t	tss
	the TSS, for software multitasking we only need one

Detailed Description

Task State Segment.

The TSS stores information for switching from user to kernel space.

See also: http://wiki.osdev.org/TSS; https://en.wikipedia.org/wiki/Task_state_segment; http://www.lowlevel.eu/wiki/Task_State_Segment; http://wiki.osdev.org/Getting_to_Ring_3; http://www.jamesmolloy.co.uk/tutorial_html/10.-User%20Mode.html

Function Documentation

void tss_init ( gdt_entry_t * gdt )

Initializes the TSS.

Parameters

gdt	pointer to the GDT

Creates a TSS descriptor in the GDT.

Sets the TSS's stack segment to the kernel stack segment.

Definition at line 35 of file tss.c.

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void tss_load ( )

Loads the TSS into the TR register.

Loads the TR (= Task Register) with the TSS's GDT selector.

Definition at line 53 of file tss.c.

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void tss_set_stack ( uint32_t stack_pointer )

Sets the TSS's kernel stack which is used to handle interrupts.

Parameters

stack_pointer the kernel stack pointer

Definition at line 48 of file tss.c.

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