Enum lpc55::protected_flash::debug::DebugSetting

pub enum DebugSetting {
    Default,
    Disabled,
    Enabled,
    Illegal,
    Authenticate,
}

Controls access of debuggers to specific subsystems.

To understand if access is possible:

• factory + customer setting: Enabled -> yes
• factor + customer set to Enabled or Authenticate -> need a prepared debug certificate (this is not implemented in this library)
• any setting Illegal => device may lock up
• any setting Disabled => access not possible!!

Peculiarities to be aware of:

• Factory settings (CC_SOCU_PIN, CC_SOCU_DFLT) can be made stricter, but not relaxed, using customer settings (DCFG_CC_SOCU_NS_PIN, DCFG_CC_SOCU_NS_DFLT)
• As long as the factory page is not sealed, the setting can be changed there.
• To change settings in the customer page, the ping/pong dance must be done.
• The enabled bit (“DFLT”) determines which setting is potentially in effect
• The fixed bit (“PIN”) determines whether a debugger may activate the potentially effective settings (by presenting a Debug Authentication certificate)
• The non-fixed enabled setting is illegal.
• All bits are written in the lower half-word, and must be also written in inverted form in the upper half-word.
• Except, it seems, the default / empty setting, where both PIN and DFLT words are all zero.

In this implementation, we disregard customer settings from configuration files, enforcing that only the firmware changes them.

TODO: We could also model the factory default, where the entire word is zeros. This would need some special handling + research.

Variants

Default

Default state at startup. Will only be accepted when writing to factory settings when all settings are default.

Disabled

Disabled at startup, debugging not possible

Enabled

Debugging enabled at startup (debugger can’t turn off). “Access to the sub-domain is always enabled.”

Illegal

According to UM 11126, 51.7.14, Table 1064: “Illegal setting. Part may lock-up if this setting is selected.”

Authenticate

Debugging disabled at startup, only authenticated debugger can access

Trait Implementations

impl Clone for DebugSetting

fn clone(&self) -> DebugSetting

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for DebugSetting

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

Formats the value using the given formatter.

impl Default for DebugSetting

fn default() -> Self

Set to enabled, so that lpc55 factory-settings does not turn off debugging on an otherwise empty key, unless explicitly configured to be turned off.

It might be possible to set the default to Self::Default here, if we research whether its valid for some settings to stay 0 in both bits and also in the “inverted” section.

impl<'de> Deserialize<'de> for DebugSetting

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>where
    __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<[bool; 2]> for DebugSetting

fn from(bits: [bool; 2]) -> Self

Converts to this type from the input type.

impl Hash for DebugSetting

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 Ord for DebugSetting

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

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Selfwhere
    Self: Sized + PartialOrd<Self>,

Restrict a value to a certain interval.

impl PartialEq<DebugSetting> for DebugSetting

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

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

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

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

impl PartialOrd<DebugSetting> for DebugSetting

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

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

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

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

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

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

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

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

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

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

impl Serialize for DebugSetting

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>where
    __S: Serializer,

Serialize this value into the given Serde serializer.

impl Copy for DebugSetting

impl Eq for DebugSetting

impl StructuralEq for DebugSetting

impl StructuralPartialEq for DebugSetting