Struct sunrise_kernel::i386::TssStruct

#[repr(C, align(128))]pub struct TssStruct {
    pub link: u16,
    _reserved1: u16,
    pub esp0: u32,
    pub ss0: u16,
    _reserved2: u16,
    pub esp1: u32,
    pub ss1: u16,
    _reserved3: u16,
    pub esp2: u32,
    pub ss2: u16,
    _reserved4: u16,
    pub cr3: u32,
    pub eip: u32,
    pub eflags: u32,
    pub eax: u32,
    pub ecx: u32,
    pub edx: u32,
    pub ebx: u32,
    pub esp: u32,
    pub ebp: u32,
    pub esi: u32,
    pub edi: u32,
    pub es: u16,
    _reserved5: u16,
    pub cs: u16,
    _reserved6: u16,
    pub ss: u16,
    _reserved7: u16,
    pub ds: u16,
    _reserved8: u16,
    pub fs: u16,
    _reserved9: u16,
    pub gs: u16,
    _reserveda: u16,
    pub ldt_selector: u16,
    _reservedb: u16,
    _reservedc: u16,
    pub iopboffset: u16,
}

The Task State Segment (TSS) is a special data structure for x86 processors which holds information about a task. The TSS is primarily suited for hardware multitasking, where each individual process has its own TSS. (see OSDEV)

Fields

link: u16

_reserved1: u16

esp0: u32

ss0: u16

_reserved2: u16

esp1: u32

ss1: u16

_reserved3: u16

esp2: u32

ss2: u16

_reserved4: u16

cr3: u32

eip: u32

eflags: u32

eax: u32

ecx: u32

edx: u32

ebx: u32

esp: u32

ebp: u32

esi: u32

edi: u32

es: u16

_reserved5: u16

cs: u16

_reserved6: u16

ss: u16

_reserved7: u16

ds: u16

_reserved8: u16

fs: u16

_reserved9: u16

gs: u16

_reserveda: u16

ldt_selector: u16

_reservedb: u16

_reservedc: u16

iopboffset: u16

Implementations

impl TssStruct

pub const fn empty() -> TssStruct

Creates an empty TssStruct.

All fields are set to 0, suitable for static declarations, so that it can live in the .bss.

The TssStruct must then be initialized with init.

Note that until it is initialized properly, the .iopboffset field will be invalid.

pub fn init(&mut self)

Fills the TSS.

The TSS is filled with kernel segments selectors, and the current cr3. Registers are set to 0.

pub fn set_esp0_stack(&mut self, esp: u32)

Set the stack pointer used to handle interrupts occuring while running in Ring3.

If an interrupt occurs while running in Ring3, it would be a security problem to use the user-controlled stack to handle the interrupt. To avoid this, we can tell the CPU to instead run the interrupt handler in a separate stack.

pub fn set_ip(&mut self, eip: u32)

Set the IP of the current task struct. When we hardware task switch to this TSS, we will resume running at the given instruction.

Trait Implementations

impl Clone for TssStruct

fn clone(&self) -> TssStruct

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for TssStruct

impl Debug for TssStruct

fn fmt(&self, f: &mut Formatter) -> Result

Formats the value using the given formatter.