Struct x86_64::structures::gdt::DescriptorFlags

pub struct DescriptorFlags { /* fields omitted */ }

Flags for a GDT descriptor. Not all flags are valid for all descriptor types.

Implementations

impl DescriptorFlags

pub const ACCESSED: DescriptorFlags

Set by the processor if this segment has been accessed. Only cleared by software. Setting this bit in software prevents GDT writes on first use.

pub const WRITABLE: DescriptorFlags

For 32-bit data segments, sets the segment as writable. For 32-bit code segments, sets the segment as readable. In 64-bit mode, ignored for all segments.

pub const CONFORMING: DescriptorFlags

For code segments, sets the segment as “conforming”, influencing the privilege checks that occur on control transfers. For 32-bit data segments, sets the segment as "expand down". In 64-bit mode, ignored for data segments.

pub const EXECUTABLE: DescriptorFlags

This flag must be set for code segments and unset for data segments.

pub const USER_SEGMENT: DescriptorFlags

This flag must be set for user segments (in contrast to system segments).

pub const DPL_RING_3: DescriptorFlags

The DPL for this descriptor is Ring 3. In 64-bit mode, ignored for data segments.

pub const PRESENT: DescriptorFlags

Must be set for any segment, causes a segment not present exception if not set.

pub const AVAILABLE: DescriptorFlags

Available for use by the Operating System

pub const LONG_MODE: DescriptorFlags

Must be set for 64-bit code segments, unset otherwise.

pub const DEFAULT_SIZE: DescriptorFlags

Use 32-bit (as opposed to 16-bit) operands. If LONG_MODE is set, this must be unset. In 64-bit mode, ignored for data segments.

pub const GRANULARITY: DescriptorFlags

Limit field is scaled by 4096 bytes. In 64-bit mode, ignored for all segments.

pub const LIMIT_0_15: DescriptorFlags

Bits 0..=15 of the limit field (ignored in 64-bit mode)

pub const LIMIT_16_19: DescriptorFlags

Bits 16..=19 of the limit field (ignored in 64-bit mode)

pub const BASE_0_23: DescriptorFlags

Bits 0..=23 of the base field (ignored in 64-bit mode, except for fs and gs)

pub const BASE_24_31: DescriptorFlags

Bits 24..=31 of the base field (ignored in 64-bit mode, except for fs and gs)

pub const fn empty() -> DescriptorFlags

Returns an empty set of flags

pub const fn all() -> DescriptorFlags

Returns the set containing all flags.

pub const fn bits(&self) -> u64

Returns the raw value of the flags currently stored.

pub fn from_bits(bits: u64) -> Option<DescriptorFlags>

Convert from underlying bit representation, unless that representation contains bits that do not correspond to a flag.

pub const fn from_bits_truncate(bits: u64) -> DescriptorFlags

Convert from underlying bit representation, dropping any bits that do not correspond to flags.

pub const unsafe fn from_bits_unchecked(bits: u64) -> DescriptorFlags

Convert from underlying bit representation, preserving all bits (even those not corresponding to a defined flag).

pub const fn is_empty(&self) -> bool

Returns true if no flags are currently stored.

pub const fn is_all(&self) -> bool

Returns true if all flags are currently set.

pub const fn intersects(&self, other: DescriptorFlags) -> bool

Returns true if there are flags common to both self and other.

pub const fn contains(&self, other: DescriptorFlags) -> bool

Returns true all of the flags in other are contained within self.

pub fn insert(&mut self, other: DescriptorFlags)

Inserts the specified flags in-place.

pub fn remove(&mut self, other: DescriptorFlags)

Removes the specified flags in-place.

pub fn toggle(&mut self, other: DescriptorFlags)

Toggles the specified flags in-place.

pub fn set(&mut self, other: DescriptorFlags, value: bool)

Inserts or removes the specified flags depending on the passed value.

impl DescriptorFlags

The following constants define default values for common GDT entries. They are all "flat" segments, meaning they can access the entire address space. These values all set WRITABLE and ACCESSED. They also match the values loaded by the syscall/sysret and sysenter/sysexit instructions.

In short, these values disable segmentation, permission checks, and access tracking at the GDT level. Kernels using these values should use paging to implement this functionality.

pub const KERNEL_DATA: Self

A kernel data segment (64-bit or flat 32-bit)

pub const KERNEL_CODE32: Self

A flat 32-bit kernel code segment

pub const KERNEL_CODE64: Self

A 64-bit kernel code segment

pub const USER_DATA: Self

A user data segment (64-bit or flat 32-bit)

pub const USER_CODE32: Self

A flat 32-bit user code segment

pub const USER_CODE64: Self

A 64-bit user code segment

Trait Implementations

impl Binary for DescriptorFlags

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

Formats the value using the given formatter.

impl BitAnd<DescriptorFlags> for DescriptorFlags

type Output = DescriptorFlags

The resulting type after applying the & operator.

fn bitand(self, other: DescriptorFlags) -> DescriptorFlags

Returns the intersection between the two sets of flags.

impl BitAndAssign<DescriptorFlags> for DescriptorFlags

fn bitand_assign(&mut self, other: DescriptorFlags)

Disables all flags disabled in the set.

impl BitOr<DescriptorFlags> for DescriptorFlags

type Output = DescriptorFlags

The resulting type after applying the | operator.

fn bitor(self, other: DescriptorFlags) -> DescriptorFlags

Returns the union of the two sets of flags.

impl BitOrAssign<DescriptorFlags> for DescriptorFlags

fn bitor_assign(&mut self, other: DescriptorFlags)

Adds the set of flags.

impl BitXor<DescriptorFlags> for DescriptorFlags

type Output = DescriptorFlags

The resulting type after applying the ^ operator.

fn bitxor(self, other: DescriptorFlags) -> DescriptorFlags

Returns the left flags, but with all the right flags toggled.

impl BitXorAssign<DescriptorFlags> for DescriptorFlags

fn bitxor_assign(&mut self, other: DescriptorFlags)

Toggles the set of flags.

impl Clone for DescriptorFlags

fn clone(&self) -> DescriptorFlags

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for DescriptorFlags

impl Debug for DescriptorFlags

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

Formats the value using the given formatter.

impl Eq for DescriptorFlags

impl Extend<DescriptorFlags> for DescriptorFlags

fn extend<T: IntoIterator<Item = DescriptorFlags>>(&mut self, iterator: T)

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬 This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬 This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl FromIterator<DescriptorFlags> for DescriptorFlags

fn from_iter<T: IntoIterator<Item = DescriptorFlags>>(
    iterator: T
) -> DescriptorFlags

Creates a value from an iterator.

impl Hash for DescriptorFlags

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl LowerHex for DescriptorFlags

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

Formats the value using the given formatter.

impl Not for DescriptorFlags

type Output = DescriptorFlags

The resulting type after applying the ! operator.

fn not(self) -> DescriptorFlags

Returns the complement of this set of flags.

impl Octal for DescriptorFlags

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

Formats the value using the given formatter.

impl Ord for DescriptorFlags

fn cmp(&self, other: &DescriptorFlags) -> Ordering

This method returns an Ordering between self and other.

#[must_use]fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl PartialEq<DescriptorFlags> for DescriptorFlags

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl PartialOrd<DescriptorFlags> for DescriptorFlags

fn partial_cmp(&self, other: &DescriptorFlags) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &DescriptorFlags) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &DescriptorFlags) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &DescriptorFlags) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &DescriptorFlags) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralEq for DescriptorFlags

impl StructuralPartialEq for DescriptorFlags

impl Sub<DescriptorFlags> for DescriptorFlags

type Output = DescriptorFlags

The resulting type after applying the - operator.

fn sub(self, other: DescriptorFlags) -> DescriptorFlags

Returns the set difference of the two sets of flags.

impl SubAssign<DescriptorFlags> for DescriptorFlags

fn sub_assign(&mut self, other: DescriptorFlags)

Disables all flags enabled in the set.

impl UpperHex for DescriptorFlags

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

Formats the value using the given formatter.