Struct DescriptorFlags

pub struct DescriptorFlags(/* private fields */);

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

Implementations

impl DescriptorFlags

pub const ACCESSED: Self = _

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: Self = _

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: Self = _

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: Self = _

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

pub const USER_SEGMENT: Self = _

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

pub const DPL_RING_3: Self = _

These two bits encode the Descriptor Privilege Level (DPL) for this descriptor. If both bits are set, the DPL is Ring 3, if both are unset, the DPL is Ring 0.

pub const PRESENT: Self = _

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

pub const AVAILABLE: Self = _

Available for use by the Operating System

pub const LONG_MODE: Self = _

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

pub const DEFAULT_SIZE: Self = _

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: Self = _

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

pub const LIMIT_0_15: Self = _

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

pub const LIMIT_16_19: Self = _

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

pub const BASE_0_23: Self = _

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

pub const BASE_24_31: Self = _

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

impl DescriptorFlags

pub const fn empty() -> Self

Get a flags value with all bits unset.

pub const fn all() -> Self

Get a flags value with all known bits set.

pub const fn bits(&self) -> u64

Get the underlying bits value.

The returned value is exactly the bits set in this flags value.

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

Convert from a bits value.

This method will return None if any unknown bits are set.

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

Convert from a bits value, unsetting any unknown bits.

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

Convert from a bits value exactly.

pub fn from_name(name: &str) -> Option<Self>

Get a flags value with the bits of a flag with the given name set.

This method will return None if name is empty or doesn’t correspond to any named flag.

pub const fn is_empty(&self) -> bool

Whether all bits in this flags value are unset.

pub const fn is_all(&self) -> bool

Whether all known bits in this flags value are set.

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

Whether any set bits in a source flags value are also set in a target flags value.

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

Whether all set bits in a source flags value are also set in a target flags value.

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

The bitwise or (|) of the bits in two flags values.

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

The intersection of a source flags value with the complement of a target flags value (&!).

This method is not equivalent to self & !other when other has unknown bits set. remove won’t truncate other, but the ! operator will.

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

The bitwise exclusive-or (^) of the bits in two flags values.

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

Call insert when value is true or remove when value is false.

pub const fn intersection(self, other: Self) -> Self

The bitwise and (&) of the bits in two flags values.

pub const fn union(self, other: Self) -> Self

The bitwise or (|) of the bits in two flags values.

pub const fn difference(self, other: Self) -> Self

The intersection of a source flags value with the complement of a target flags value (&!).

This method is not equivalent to self & !other when other has unknown bits set. difference won’t truncate other, but the ! operator will.

pub const fn symmetric_difference(self, other: Self) -> Self

The bitwise exclusive-or (^) of the bits in two flags values.

pub const fn complement(self) -> Self

The bitwise negation (!) of the bits in a flags value, truncating the result.

impl DescriptorFlags

pub const fn iter(&self) -> Iter<DescriptorFlags>

Yield a set of contained flags values.

Each yielded flags value will correspond to a defined named flag. Any unknown bits will be yielded together as a final flags value.

pub const fn iter_names(&self) -> IterNames<DescriptorFlags>

Yield a set of contained named flags values.

This method is like iter, except only yields bits in contained named flags. Any unknown bits, or bits not corresponding to a contained flag will not be yielded.

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 for DescriptorFlags

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

The bitwise and (&) of the bits in two flags values.

type Output = DescriptorFlags

The resulting type after applying the & operator.

impl BitAndAssign for DescriptorFlags

fn bitand_assign(&mut self, other: Self)

The bitwise and (&) of the bits in two flags values.

impl BitOr for DescriptorFlags

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

The bitwise or (|) of the bits in two flags values.

type Output = DescriptorFlags

The resulting type after applying the | operator.

impl BitOrAssign for DescriptorFlags

fn bitor_assign(&mut self, other: Self)

The bitwise or (|) of the bits in two flags values.

impl BitXor for DescriptorFlags

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

The bitwise exclusive-or (^) of the bits in two flags values.

type Output = DescriptorFlags

The resulting type after applying the ^ operator.

impl BitXorAssign for DescriptorFlags

fn bitxor_assign(&mut self, other: Self)

The bitwise exclusive-or (^) of the bits in two flags values.

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 Debug for DescriptorFlags

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

Formats the value using the given formatter.

impl Extend<DescriptorFlags> for DescriptorFlags

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

The bitwise or (|) of the bits in each flags value.

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 Flags for DescriptorFlags

const FLAGS: &'static [Flag<DescriptorFlags>] = _

The set of defined flags.

type Bits = u64

The underlying bits type.

fn bits(&self) -> u64

Get the underlying bits value.

fn from_bits_retain(bits: u64) -> DescriptorFlags

Convert from a bits value exactly.

fn empty() -> Self

Get a flags value with all bits unset.

fn all() -> Self

Get a flags value with all known bits set.

fn from_bits(bits: Self::Bits) -> Option<Self>

Convert from a bits value.

fn from_bits_truncate(bits: Self::Bits) -> Self

Convert from a bits value, unsetting any unknown bits.

fn from_name(name: &str) -> Option<Self>

Get a flags value with the bits of a flag with the given name set.

fn iter(&self) -> Iter<Self>

Yield a set of contained flags values.

fn iter_names(&self) -> IterNames<Self>

Yield a set of contained named flags values.

fn is_empty(&self) -> bool

Whether all bits in this flags value are unset.

fn is_all(&self) -> bool

Whether all known bits in this flags value are set.

fn intersects(&self, other: Self) -> bool

where Self: Sized,

Whether any set bits in a source flags value are also set in a target flags value.

fn contains(&self, other: Self) -> bool

where Self: Sized,

Whether all set bits in a source flags value are also set in a target flags value.

fn insert(&mut self, other: Self)

where Self: Sized,

The bitwise or (|) of the bits in two flags values.

fn remove(&mut self, other: Self)

where Self: Sized,

The intersection of a source flags value with the complement of a target flags value (&!).

fn toggle(&mut self, other: Self)

where Self: Sized,

The bitwise exclusive-or (^) of the bits in two flags values.

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

where Self: Sized,

Call Flags::insert when value is true or Flags::remove when value is false.

fn intersection(self, other: Self) -> Self

The bitwise and (&) of the bits in two flags values.

fn union(self, other: Self) -> Self

The bitwise or (|) of the bits in two flags values.

fn difference(self, other: Self) -> Self

The intersection of a source flags value with the complement of a target flags value (&!).

fn symmetric_difference(self, other: Self) -> Self

The bitwise exclusive-or (^) of the bits in two flags values.

fn complement(self) -> Self

The bitwise negation (!) of the bits in a flags value, truncating the result.

impl FromIterator<DescriptorFlags> for DescriptorFlags

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

The bitwise or (|) of the bits in each flags value.

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, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl IntoIterator for DescriptorFlags

type Item = DescriptorFlags

The type of the elements being iterated over.

type IntoIter = Iter<DescriptorFlags>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl LowerHex for DescriptorFlags

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

Formats the value using the given formatter.

impl Not for DescriptorFlags

fn not(self) -> Self

The bitwise negation (!) of the bits in a flags value, truncating the result.

type Output = DescriptorFlags

The resulting type after applying the ! operator.

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.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for DescriptorFlags

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl PublicFlags for DescriptorFlags

type Primitive = u64

The type of the underlying storage.

type Internal = InternalBitFlags

The type of the internal field on the generated flags type.

impl Sub for DescriptorFlags

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

The intersection of a source flags value with the complement of a target flags value (&!).

This method is not equivalent to self & !other when other has unknown bits set. difference won’t truncate other, but the ! operator will.

type Output = DescriptorFlags

The resulting type after applying the - operator.

impl SubAssign for DescriptorFlags

fn sub_assign(&mut self, other: Self)

The intersection of a source flags value with the complement of a target flags value (&!).

This method is not equivalent to self & !other when other has unknown bits set. difference won’t truncate other, but the ! operator will.

impl UpperHex for DescriptorFlags

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

Formats the value using the given formatter.

impl Copy for DescriptorFlags

impl Eq for DescriptorFlags

impl StructuralPartialEq for DescriptorFlags