Struct WasmHeader 

#[repr(C)]
pub struct WasmHeader {

    pub wasm_magic: u32,
    pub header_version: u16,
    pub role: u8,
    pub target: u8,
    pub required_features: u16,
    pub export_count: u16,
    pub bytecode_size: u32,
    pub compressed_size: u32,
    pub compression: u8,
    pub min_memory_pages: u8,
    pub max_memory_pages: u8,
    pub table_count: u8,
    pub bytecode_hash: [u8; 32],
    pub bootstrap_priority: u8,
    pub interpreter_type: u8,
    pub reserved: [u8; 6],
}

64-byte header for WASM_SEG payloads.

Follows the standard 64-byte SegmentHeader. The WASM bytecode follows immediately after this header within the segment payload.

For self-bootstrapping files, two WASM_SEGs are present:

1. role = Interpreter — a minimal WASM interpreter (~50 KB)
2. role = Microkernel — the RVF query engine (~5.5 KB)

The bootstrap sequence is:

1. Host reads file, finds WASM_SEG with role = Interpreter
2. Host loads interpreter bytecode into any available execution engine
3. Interpreter instantiates the microkernel WASM_SEG
4. Microkernel processes VEC_SEG, INDEX_SEG, etc.

Fields

wasm_magic: u32

Magic: WASM_MAGIC (0x5256574D, “RVWM”).

header_version: u16

WasmHeader format version (currently 1).

role: u8

Role in the bootstrap chain (see WasmRole).

target: u8

Target platform (see WasmTarget).

required_features: u16

Required WASM features bitfield (see WASM_FEAT_*).

export_count: u16

Number of exports in the WASM module.

bytecode_size: u32

Uncompressed WASM bytecode size (bytes).

compressed_size: u32

Compressed bytecode size (0 if uncompressed).

compression: u8

Compression algorithm (same enum as SegmentHeader).

min_memory_pages: u8

Minimum linear memory pages required (64 KB each).

max_memory_pages: u8

Maximum linear memory pages (0 = no limit).

table_count: u8

Number of WASM tables.

bytecode_hash: [u8; 32]

SHAKE-256-256 hash of uncompressed bytecode.

bootstrap_priority: u8

Priority order for bootstrap resolution (lower = tried first). The interpreter with lowest priority is used when multiple are present.

interpreter_type: u8

If role=Interpreter, this is the interpreter type: 0x00 = generic stack machine, 0x01 = wasm3-compatible, 0x02 = wamr-compatible, 0x03 = wasmi-compatible.

reserved: [u8; 6]

Reserved (must be zero).

Implementations

impl WasmHeader

pub fn to_bytes(&self) -> [u8; 64]

Serialize the header to a 64-byte little-endian array.

pub fn from_bytes(data: &[u8; 64]) -> Result<Self, RvfError>

Deserialize a WasmHeader from a 64-byte slice.

Trait Implementations

impl Clone for WasmHeader

fn clone(&self) -> WasmHeader

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for WasmHeader

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

Formats the value using the given formatter.

impl Copy for WasmHeader