Raw Linux executables

The synchronous raw runtime supports x86-64 and ARM64 Linux with libc = "none", static linking and static relocation. Select silk/raw_start as a named runtime module and _start as the loader entry. The application exports ordinary Silk pub fn main(inputs: &ProcessInputs) -> i32, importing ProcessInputs from silk.raw_process_inputs. No C startup object or generated hosted entry supplies this composition.

The source entry captures the kernel stack before changing it, observes the platform stack-alignment contract and calls the source initializer. The initializer checks the argument terminator and auxiliary vector, requires exactly one positive power-of-two AT_PAGESZ, and invokes the application once. Invalid required startup facts exit with status 127. Normal application return terminates the process with the low eight bits of its result through Linux exit_group.

ProcessInputs borrows the kernel-provided argument and environment strings for the process lifetime. Its decoder is unsafe: the caller must supply the complete, aligned, readable, terminated kernel stack image. Validation of required facts does not make an arbitrary address safe to inspect. Accessors return nullable pointers for missing indices and do not allocate or copy strings.

silk.raw_linux provides unsafe syscall0 through syscall6 and a non-returning one-argument syscall operation. These follow Linux register conventions, declare memory effects, and expose the machine-word result. error decodes unsigned -4095 through -1 into positive error numbers. read and write expose partial transfers, EOF and errors directly; callers own retry and progress policy. Pointer conversion uses typed target assembly and grants neither ownership nor memory validity.

Mapping.allocate in silk.raw_mapping reserves an anonymous private read/write mapping. The page size must come from validated process inputs. Size must be positive; alignment and page size must be powers of two. Checked arithmetic rejects overflow before the syscall. Over-aligned allocations retain one complete mapping and return an aligned usable range whose initial bytes are zero. An affine owner releases the complete mapping on structured drop, or explicit Mapping.release consumes it and reports the kernel result. Neither path retries release. Unsafe pointer access must stay within the usable range and the owner's lifetime.

This composition supplies no execution-storage or terminal-reporting capability. Artifacts requesting the retained generated language runtime fail before object emission. The physical link planner provides no libc or CRT, and admitted source memory helpers remain subject to post-object helper accounting. LTO remains unsupported. Fatal traps do not promise cleanup or reporting.

The required raw Linux conformance fixture independently compiles pinned Linux UAPI declarations, executes debug and optimized artifacts on both architectures, and inspects object disassembly and final ELF closure. The final executable must be ET_EXEC with no interpreter, dynamic dependency or undefined symbol.