Struct Descriptor

#[repr(transparent)]
pub struct Descriptor(u64);

Describes the structure of segment descriptors

A data structure that contains size, position, access rights, and purpose of any segment. Segment descriptors are used in both the GDT, as well as in LDTs.

• ISDMv3, 3.4.5; Segment Descriptors
• AAPMv2, 4.7 Legacy Segment Descriptors

Tuple Fields

0: u64

Implementations

impl Descriptor

const LIMIT_LOW_BITS: usize = 16usize

const LIMIT_LOW_OFFSET: usize = 0usize

const BASE_LOW_BITS: usize = 24usize

const BASE_LOW_OFFSET: usize = 16usize

const KIND_BITS: usize = 4usize

const KIND_OFFSET: usize = 40usize

const DESCRIPTOR_KIND_BITS: usize = 1usize

const DESCRIPTOR_KIND_OFFSET: usize = 44usize

const RING_BITS: usize = 2usize

const RING_OFFSET: usize = 45usize

const PRESENT_BITS: usize = 1usize

const PRESENT_OFFSET: usize = 47usize

const LIMIT_HIGH_BITS: usize = 4usize

const LIMIT_HIGH_OFFSET: usize = 48usize

const AVAILABLE_BITS: usize = 1usize

const AVAILABLE_OFFSET: usize = 52usize

const CUSTOM_BITS: usize = 2usize

const CUSTOM_OFFSET: usize = 53usize

const PAGES_BITS: usize = 1usize

const PAGES_OFFSET: usize = 55usize

const BASE_HIGH_BITS: usize = 8usize

const BASE_HIGH_OFFSET: usize = 56usize

pub const fn new() -> Self

Creates a new default initialized bitfield.

pub const fn from_bits(bits: u64) -> Self

Convert from bits.

pub const fn into_bits(self) -> u64

Convert into bits.

const fn limit_low(&self) -> u32

Least-significant bits of segment size (influenced by Self::pages!)

Bits: 0..16

const fn with_limit_low_checked(self, value: u32) -> Result<Self, ()>

Least-significant bits of segment size (influenced by Self::pages!)

Bits: 0..16

const fn with_limit_low(self, value: u32) -> Self

Least-significant bits of segment size (influenced by Self::pages!)

Bits: 0..16

fn set_limit_low(&mut self, value: u32)

Least-significant bits of segment size (influenced by Self::pages!)

Bits: 0..16

fn set_limit_low_checked(&mut self, value: u32) -> Result<(), ()>

Least-significant bits of segment size (influenced by Self::pages!)

Bits: 0..16

const fn base_low(&self) -> u32

Least-significant bits of base address

Bits: 16..40

const fn with_base_low_checked(self, value: u32) -> Result<Self, ()>

Least-significant bits of base address

Bits: 16..40

const fn with_base_low(self, value: u32) -> Self

Least-significant bits of base address

Bits: 16..40

fn set_base_low(&mut self, value: u32)

Least-significant bits of base address

Bits: 16..40

fn set_base_low_checked(&mut self, value: u32) -> Result<(), ()>

Least-significant bits of base address

Bits: 16..40

pub const fn kind(&self) -> u8

Type: defines which kind code/data/system descriptor this is. This depends on Self::descriptor_kind.

Bits: 40..44

pub const fn with_kind_checked(self, value: u8) -> Result<Self, ()>

Type: defines which kind code/data/system descriptor this is. This depends on Self::descriptor_kind.

Bits: 40..44

pub const fn with_kind(self, value: u8) -> Self

Type: defines which kind code/data/system descriptor this is. This depends on Self::descriptor_kind.

Bits: 40..44

pub fn set_kind(&mut self, value: u8)

Type: defines which kind code/data/system descriptor this is. This depends on Self::descriptor_kind.

Bits: 40..44

pub fn set_kind_checked(&mut self, value: u8) -> Result<(), ()>

Type: defines which kind code/data/system descriptor this is. This depends on Self::descriptor_kind.

Bits: 40..44

pub const fn descriptor_kind(&self) -> bool

Descriptor type: if true code or data, else system

Bits: 44..45

pub const fn with_descriptor_kind_checked(self, value: bool) -> Result<Self, ()>

Descriptor type: if true code or data, else system

Bits: 44..45

pub const fn with_descriptor_kind(self, value: bool) -> Self

Descriptor type: if true code or data, else system

Bits: 44..45

pub fn set_descriptor_kind(&mut self, value: bool)

Descriptor type: if true code or data, else system

Bits: 44..45

pub fn set_descriptor_kind_checked(&mut self, value: bool) -> Result<(), ()>

Descriptor type: if true code or data, else system

Bits: 44..45

pub const fn ring(&self) -> Ring

Ring for this segment

Bits: 45..47

pub const fn with_ring_checked(self, value: Ring) -> Result<Self, ()>

Ring for this segment

Bits: 45..47

pub const fn with_ring(self, value: Ring) -> Self

Ring for this segment

Bits: 45..47

pub fn set_ring(&mut self, value: Ring)

Ring for this segment

Bits: 45..47

pub fn set_ring_checked(&mut self, value: Ring) -> Result<(), ()>

Ring for this segment

Bits: 45..47

pub const fn present(&self) -> bool

Entry is ignored if set to false

Bits: 47..48

pub const fn with_present_checked(self, value: bool) -> Result<Self, ()>

Entry is ignored if set to false

Bits: 47..48

pub const fn with_present(self, value: bool) -> Self

Entry is ignored if set to false

Bits: 47..48

pub fn set_present(&mut self, value: bool)

Entry is ignored if set to false

Bits: 47..48

pub fn set_present_checked(&mut self, value: bool) -> Result<(), ()>

Entry is ignored if set to false

Bits: 47..48

const fn limit_high(&self) -> u32

Most-significant bits of segment size

Bits: 48..52

const fn with_limit_high_checked(self, value: u32) -> Result<Self, ()>

Most-significant bits of segment size

Bits: 48..52

const fn with_limit_high(self, value: u32) -> Self

Most-significant bits of segment size

Bits: 48..52

fn set_limit_high(&mut self, value: u32)

Most-significant bits of segment size

Bits: 48..52

fn set_limit_high_checked(&mut self, value: u32) -> Result<(), ()>

Most-significant bits of segment size

Bits: 48..52

pub const fn available(&self) -> bool

Bit which can be freely used for other purposes

Bits: 52..53

pub const fn with_available_checked(self, value: bool) -> Result<Self, ()>

Bit which can be freely used for other purposes

Bits: 52..53

pub const fn with_available(self, value: bool) -> Self

Bit which can be freely used for other purposes

Bits: 52..53

pub fn set_available(&mut self, value: bool)

Bit which can be freely used for other purposes

Bits: 52..53

pub fn set_available_checked(&mut self, value: bool) -> Result<(), ()>

Bit which can be freely used for other purposes

Bits: 52..53

pub const fn custom(&self) -> u8

The meaning of these bits are related to Self::descriptor_kind and Self::kind

Bits: 53..55

pub const fn with_custom_checked(self, value: u8) -> Result<Self, ()>

The meaning of these bits are related to Self::descriptor_kind and Self::kind

Bits: 53..55

pub const fn with_custom(self, value: u8) -> Self

The meaning of these bits are related to Self::descriptor_kind and Self::kind

Bits: 53..55

pub fn set_custom(&mut self, value: u8)

The meaning of these bits are related to Self::descriptor_kind and Self::kind

Bits: 53..55

pub fn set_custom_checked(&mut self, value: u8) -> Result<(), ()>

The meaning of these bits are related to Self::descriptor_kind and Self::kind

Bits: 53..55

pub const fn pages(&self) -> bool

Uses page granularity for the segment limit (instead of bytes)

Bits: 55..56

pub const fn with_pages_checked(self, value: bool) -> Result<Self, ()>

Uses page granularity for the segment limit (instead of bytes)

Bits: 55..56

pub const fn with_pages(self, value: bool) -> Self

Uses page granularity for the segment limit (instead of bytes)

Bits: 55..56

pub fn set_pages(&mut self, value: bool)

Uses page granularity for the segment limit (instead of bytes)

Bits: 55..56

pub fn set_pages_checked(&mut self, value: bool) -> Result<(), ()>

Uses page granularity for the segment limit (instead of bytes)

Bits: 55..56

const fn base_high(&self) -> u8

Most-significant bits of base address

Bits: 56..64

const fn with_base_high_checked(self, value: u8) -> Result<Self, ()>

Most-significant bits of base address

Bits: 56..64

const fn with_base_high(self, value: u8) -> Self

Most-significant bits of base address

Bits: 56..64

fn set_base_high(&mut self, value: u8)

Most-significant bits of base address

Bits: 56..64

fn set_base_high_checked(&mut self, value: u8) -> Result<(), ()>

Most-significant bits of base address

Bits: 56..64

impl Descriptor

pub const fn segment( memory: RangeInclusive<u32>, code: bool, ring: Ring, ) -> Self

Create a code/data segment descriptor

pub fn tss(tss: *const TaskStateSegment) -> Self

Creates a new task state segment descriptor for the Global Descriptor Table.

pub const fn base(&self) -> u32

Base/starting address

pub const fn with_base(self, v: u32) -> Self

Base/starting address

pub const fn limit(&self) -> u32

Segment size minus one

pub const fn with_limit(self, v: u32) -> Self

Segment size minus one

Trait Implementations

impl Clone for Descriptor

fn clone(&self) -> Descriptor

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Descriptor

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

Formats the value using the given formatter.

impl Default for Descriptor

fn default() -> Self

Returns the “default value” for a type.

impl From<Descriptor> for u64

fn from(v: Descriptor) -> u64

Converts to this type from the input type.

impl From<u64> for Descriptor

fn from(v: u64) -> Self

Converts to this type from the input type.

impl PartialEq for Descriptor

fn eq(&self, other: &Descriptor) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Descriptor

impl Eq for Descriptor

impl StructuralPartialEq for Descriptor