Files
StarForth/src/starkernel
Robert Allan JamesandClaude Sonnet 5 2e7e957680 Milestone 6 (ACL/PKI): Ed25519 verify + SHA-512, built from scratch
New freestanding, verify-only Ed25519 (RFC 8032) implementation:
include/starkernel/{sha512,fe25519,scalar25519,ed25519}.h +
src/starkernel/crypto/{sha512,fe25519,scalar25519,ed25519}.c, wired into
Makefile.starkernel. Kernel never signs or generates keys -- only
ed25519_verify() is needed; signing happens in the host-side mkcapsule
build tool via libsodium/OpenSSL.

Confirmed __int128 multiply/add/shift-by-constant compile with zero
undefined symbols on all three target toolchains (only division needs
libgcc's __udivti3, per timer.c's existing documented finding -- that
file's comment updated to narrow the claim, since it had been read as
"avoid __int128 entirely"). This enabled the standard 5-limb radix-2^51
field arithmetic representation.

An abandoned first attempt (10-limb radix-2^26, avoiding __int128 out of
premature caution) hit two real bugs, both invisible on inspection and
found only by property-based testing against Python's own bignum
arithmetic: a non-uniform-radix limb misalignment in multiplication, and
a double-counted carry. Verification chain: SHA-512 against known +
boundary vectors (7/7); field arithmetic property-tested 25,045 cases;
scalar-mod-L arithmetic 300 cases (L confirmed prime via Miller-Rabin
first); full verify() end-to-end against 110 real signatures from
Python's cryptography library, including tampered inputs and the RFC
8032 S>=L malleability attack -- all correctly accepted/rejected.

Compiles clean (zero warnings) and links on all three architectures,
confirmed via the mandatory three-arch QEMU boot. The code is linked but
not yet called from anywhere -- wiring into capsule_birth.c needs a
from-scratch X.509/DER parser first (Captain Bob chose real X.509 over a
raw-blob cert format this session), which is the next open item.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HZ8kNoTuP63pbQtro4qvrm
2026-08-22 12:41:26 -04:00
..

src/starkernel/

LithosAnanke — the bare-metal UEFI kernel that boots StarForth directly on hardware (amd64/aarch64/riscv64). Built only via Makefile.starkernel; the only valid acceptance test is the three-arch QEMU boot (see .claude/CLAUDE.md), never make test.

  • kernel_main.c — kernel entry point, driving the boot milestones (console init, PMM, VMM, interrupts, timers, kmalloc heap, VM bootstrap).
  • repl.c — kernel REPL.
  • doe_log.c — kernel-side DoE (Design of Experiments) metrics logging.

Subdirectories:

  • arch/{amd64,aarch64,riscv64}/ — per-architecture support (APIC/GIC/ PLIC interrupt controller, timers, boot/ISR assembly).
  • boot/ — UEFI loader, ELF loading, kernel command-line parsing.
  • capsule/ — capsule birth/run/load/validate pipeline.
  • hal/ — hardware-abstraction-layer implementation (console, framebuffer, VT100, memory, host services).
  • hash/ — XXHash64 content-addressing implementation.
  • math/ — kernel-build Q48.16 fixed-point arithmetic.
  • memory/ — physical/virtual memory managers and the kernel heap.
  • pci/ — PCI bus enumeration.
  • virtio/ — VirtIO block device driver.
  • vm/ — kernel VM subsystem (bootstrap, core interpreter, parity logging, capsule arena).

See include/starkernel/README.md for the corresponding headers.