Struct Config

pub struct Config {
    pub format_costs: Option<Vec<FormatCostEntry>>,
    /* private fields */
}

This type is fidl::Persist()’ed in the sysmem_config.persistent_fidl file within the sysmem domain config by the assembly tool, and read by the sysmem driver.

Normally json[5] would be preferable for config, but we generate this config in rust using FIDL types (to avoid repetition and to take advantage of FIDL rust codegen), and there’s no json schema for FIDL types.

Currently there is no mechanism to change anything in this config at runtime or from boot to boot. This config is static per run of the assembly tool.

See src/lib/assembly/config_schema/src/platform_config/sysmem_config.rs for aspects of sysmem config which are specified directly inline in board info or assembly platform config. The two parts of sysmem config don’t (currently) overlap. The config here is for aspects of sysmem config which would be too verbose for direct inclusion in board info or assembly platform config. In addition, some/most of the pixel format cost entries are programmatically generated (as of this comment).

Prior to aggregation by assembly tool, there are multiple .persistent_fidl files each storing its own Config instance. The board info and assembly platform config lists the input persistent_fidl files, with board info logically before assembly platform config. The overall list of files is processed, which allows later files to override/replace info in prior files.

Because this type is only intended for use with persistent fidl, where the length of a serialized instance isn’t bounded, we don’t bound the internal vector element counts.

Fields

format_costs: Option<Vec<FormatCostEntry>>

This is the ordered list of FormatCost entries which will be considered by sysmem when breaking ties among formats supported by all participants of a buffer collection.

During config aggregation, if a later entry has matching FormatCostKey, the earlier entry is omitted/removed. This allows later files to override entries in earlier files, and allows files specified in assembly platform config to override entries in files specified in the board info.

This vector will normally not have any two entries with matching pixel_format, pixel_format_modifier, and buffer_usage_bits in the Config instance loaded from sysmem_config.persistent_fidl by sysmem. If somehow two entries do match in those fields, sysmem can ignore all but one of the entries chosen arbitrarily.

Trait Implementations

impl Clone for Config

fn clone(&self) -> Config

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Config

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

Formats the value using the given formatter.

impl<D: ResourceDialect> Decode<Config, D> for Config

fn new_empty() -> Self

Creates a valid instance of Self. The specific value does not matter, since it will be overwritten by decode.

unsafe fn decode( &mut self, decoder: &mut Decoder<'_, D>, offset: usize, depth: Depth, ) -> Result<()>

Decodes an object of type T from the decoder’s buffers into self.

impl Default for Config

fn default() -> Config

Returns the “default value” for a type.

impl<D: ResourceDialect> Encode<Config, D> for &Config

unsafe fn encode( self, encoder: &mut Encoder<'_, D>, offset: usize, depth: Depth, ) -> Result<()>

Encodes the object into the encoder’s buffers. Any handles stored in the object are swapped for Handle::INVALID.

impl PartialEq for Config

fn eq(&self, other: &Config) -> 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 TypeMarker for Config

type Owned = Config

The owned Rust type which this FIDL type decodes into.

fn inline_align(_context: Context) -> usize

Returns the minimum required alignment of the inline portion of the encoded object. It must be a (nonzero) power of two.

fn inline_size(_context: Context) -> usize

Returns the size of the inline portion of the encoded object, including padding for alignment. Must be a multiple of inline_align.

fn encode_is_copy() -> bool

Returns true if the memory layout of Self::Owned matches the FIDL wire format and encoding requires no validation. When true, we can optimize encoding arrays and vectors of Self::Owned to a single memcpy.

fn decode_is_copy() -> bool

Returns true if the memory layout of Self::Owned matches the FIDL wire format and decoding requires no validation. When true, we can optimize decoding arrays and vectors of Self::Owned to a single memcpy.

impl ValueTypeMarker for Config

type Borrowed<'a> = &'a Config

The Rust type to use for encoding. This is a particular Encode<Self> type cheaply obtainable from &Self::Owned. There are three cases:

fn borrow(value: &<Self as TypeMarker>::Owned) -> Self::Borrowed<'_>

Cheaply converts from &Self::Owned to Self::Borrowed.

impl Persistable for Config

impl StructuralPartialEq for Config