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
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.