Files
LithosAnanake/include/starkernel/capsule_runcap.h
T
Robert Allan JamesandClaude Sonnet 5 e1e839258d Phase D: RUNCAP -- runtime capsule construction from thumbdrive content
capsule_runcap_birth() (new capsule_runcap.h/.c): builds a heap-only,
single-entry CapsuleDirHeader + CapsuleDesc + CapsuleNameEntry + arena
from a home-blocks drive's identity_src region (skipping the first
devblock, reserved for MINT's user_identity_seed_t record) and hands it
to the existing, unmodified capsule_birth_baby() -- no new birth
mechanism, matching FABRIC-3.md §F.6's own trace.

Found and closed a real gap in that trace along the way:
capsule_birth_baby()'s signature check calls capsule_get_signatures(),
which unconditionally returns the compile-time-baked global array --
meaningless for a heap-built directory, where index 0 would compare
RUNCAP's own content against whatever real capsule happens to occupy
that slot in the baked array (guaranteed-wrong, not a security check).
Added an explicit skip_pki_sig flag (0 for all 4 existing call sites,
1 for RUNCAP): that content's trust comes from CERTVERIFY, a separate
root, not the capsule-PKI chain.

Also found live: capsule_birth_baby() never sets the registry entry's
own .name (every existing caller does this itself afterward via
capsule_vm_registry_set_name() -- RUNCAP now does too), and
capsule_exec_payload() requires a "Block NNNN" header per chunk of
content or it's silently skipped, never executed -- not a bug, but
necessary context for whoever authors MINT's default personality
content next.

Added a small accessor pair (repl.h/.c) exposing the currently attached
home-blocks device/sig -- the same gap F.9's own BINDSTEP scoping had
already flagged, needed by both.

Verified end-to-end live in QEMU: synthetic identity-source content
written directly to a thumbdrive image's raw devblocks (no capsule
build, no mkcapsule) was read, compiled, and executed by a genuinely
new VM via a diagnostic RUNCAP-TEST word -- confirmed via VM-EXEC
invoking a word defined only in that source. Clean 3-architecture
regression boot (no RUNCAP drive attached) confirms no side effects.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019ZGkimpfyh63EZyRkNbkPD
2026-08-28 14:29:42 -04:00

76 lines
2.9 KiB
C
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
/*
StarForth — Steady-State Virtual Machine Runtime
Copyright (c) 20232025 Robert A. James
All rights reserved.
Licensed under the StarForth License, Version 1.0
*/
/**
* capsule_runcap.h - RUNCAP: runtime capsule construction from thumbdrive
* content (FABRIC-3.md §F.6/§F.18).
*
* A user's identity source (raw FORTH init/personality text, minted by
* MINT into a home-blocks drive's identity_src region) never exists at
* build time, so it can never appear in the compile-time-baked capsule
* directory. This builds a heap-only, single-entry CapsuleDirHeader +
* CapsuleDesc + CapsuleNameEntry + arena from that region and hands it to
* the existing, unmodified capsule_birth_baby() -- no new birth mechanism,
* per §F.6's own trace ("capsule_birth_baby() is already generic").
*
* Does not verify the caller has already run CERTVERIFY -- that's the
* caller's responsibility (WIREBIND, not yet built). This function's own
* job is narrow: read the region, construct the directory, birth it.
*/
#ifndef STARKERNEL_CAPSULE_RUNCAP_H
#define STARKERNEL_CAPSULE_RUNCAP_H
#ifdef __STARKERNEL__
#include <stdint.h>
#include "starkernel/capsule_run.h" /* CapsuleRunResult */
#include "starkernel/vm_uuid.h" /* VMUuid */
#include "starkernel/homeblocks_sig.h" /* homeblocks_sig_t */
struct blkio_dev;
/**
* capsule_runcap_birth - Birth a VM from a home-blocks drive's own
* identity_src region.
*
* Reads sig->identity_src_devblocks devblocks starting at
* sig->identity_src_offset. The first devblock is the identity's own
* user_identity_seed_t record (MINT, §F.8) and is skipped here -- RUNCAP
* only cares about the FORTH source that follows it. Refuses cleanly
* (CAPSULE_RUN_ERR_INVALID) if identity_src_offset is 0 (never minted) or
* identity_src_devblocks < 2 (no source content beyond the seed record).
*
* The heap-allocated directory/descriptor/name/arena are never freed --
* deliberate, matching kernel_main.c's own compile-time-directory-to-heap
* copy at Mama's own birth (also never freed): a VM's IDENTITY exec reads
* directly from this arena, and nothing in this codebase frees capsule
* arenas after a successful birth today.
*
* @param dev Already-open block device for the attached drive.
* @param sig Already-verified homeblocks_sig_t read from it.
* @param vm_name Symbolic name for the new VM (becomes both the
* capsule's own single directory entry name and the
* VM registry name).
* @param out_vm_id Output: assigned VM ID.
* @param out_vm_ctx Output: new VM context (may be NULL if not needed).
* @return CAPSULE_RUN_OK on success, error code otherwise.
*/
CapsuleRunResult capsule_runcap_birth(
struct blkio_dev *dev,
const homeblocks_sig_t *sig,
const char *vm_name,
VMUuid *out_vm_id,
void **out_vm_ctx
);
#endif /* __STARKERNEL__ */
#endif /* STARKERNEL_CAPSULE_RUNCAP_H */