Files
LithosAnanake/src/starkernel/homeblocks_sig.c
T
Robert Allan JamesandClaude Sonnet 5 b031b802e3 Rename FABRIC series: FABRIC.md->0, FABRIC-2.md->1, FABRIC-3.md->2, FABRIC-4.md unchanged
FABRIC.md -> FABRIC-0.md
FABRIC-2.md -> FABRIC-1.md
FABRIC-3.md -> FABRIC-2.md (the current/living document)
FABRIC-4.md unchanged (new #3 to follow separately)

Every cross-reference repo-wide updated to match, including doc-comment
citations inside kernel source (.c/.h) files -- done via an ordered
placeholder substitution (FABRIC-3.md->placeholder2, FABRIC-2.md->
placeholder1, FABRIC.md->placeholder0, then placeholders resolved to
final names) in a single pass per file to avoid double-shifting
already-renamed references.

One line in capsules/font.4th grew past the 64-char block-format limit
as a side effect of the longer filename; shortened it and reverified
with mkcapsule --lint (34/34 pass) before rebuilding.

Verified 3-arch boot to ok> (amd64/aarch64/riscv64, each in the
foreground) after the fix; logs and DoE CSVs from this session's
verification runs included per this repo's own audit-artifact
convention.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019YcT3H2PQeyujrzjqS3Var
2026-09-04 11:22:51 -04:00

88 lines
3.1 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) 2023–2025 Robert A. James
All rights reserved.
This file is part of the StarForth project.
Licensed under the StarForth License, Version 1.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at:
https://github.com/star.4th@proton.me/StarForth/LICENSE.txt
This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
express or implied, including but not limited to the warranties of
merchantability, fitness for a particular purpose, and noninfringement.
See the License for the specific language governing permissions and
limitations under the License.
*/
/**
* homeblocks_sig.c - Drive signature check (FABRIC-2.md, Milestone 4).
* See starkernel/homeblocks_sig.h for the format and interface design.
*/
#include "starkernel/homeblocks_sig.h"
#include <stddef.h>
#include <string.h>
#include "blkio.h"
#include "block_subsystem.h" /* compute_crc64() -- same CRC-64/ISO this file's
* check reuses rather than duplicating */
uint64_t homeblocks_sig_compute_crc(const homeblocks_sig_t *sig) {
/* Covers every field up to but not including hdr_crc itself (and never
* _pad, which sits after it) -- offsetof is the exact boundary, not a
* hand-counted byte offset that could drift out of sync with the
* struct's own field list. */
size_t crc_span = offsetof(homeblocks_sig_t, hdr_crc);
return compute_crc64((const uint8_t *)sig, crc_span);
}
homeblocks_sig_result_t homeblocks_sig_check(struct blkio_dev *dev,
uint32_t sig_start_fblock,
homeblocks_sig_t *out_sig) {
uint8_t buf[4096];
uint32_t i;
homeblocks_sig_t local;
uint64_t expected_crc;
if (!dev) return HOMEBLOCKS_SIG_READ_ERROR;
/* homeblocks_sig_t is exactly one 4KiB devblock; blkio's own unit is a
* 1KiB "forth block" (BLKIO_FORTH_BLOCK_SIZE), so the header spans 4
* consecutive reads starting at sig_start_fblock. */
for (i = 0; i < 4; i++) {
if (blkio_read((blkio_dev_t *)dev, sig_start_fblock + i,
buf + (size_t)i * BLKIO_FORTH_BLOCK_SIZE) != BLKIO_OK) {
return HOMEBLOCKS_SIG_READ_ERROR;
}
}
/* Copy into a properly-aligned local rather than reinterpreting buf's
* address directly -- buf is only byte-aligned, and homeblocks_sig_t
* has uint64_t members; a raw cast would be a strict-aliasing and
* alignment violation for no benefit over one memcpy. */
memcpy(&local, buf, sizeof(local));
if (HOMEBLOCKS_SIG_GET_MAGIC(local.magic) != (uint32_t)(HOMEBLOCKS_SIG_MAGIC & 0xFFFFFFFFULL)) {
return HOMEBLOCKS_SIG_BLANK;
}
if (HOMEBLOCKS_SIG_GET_VERSION(local.magic) != HOMEBLOCKS_SIG_VERSION_0) {
return HOMEBLOCKS_SIG_BAD_VERSION;
}
expected_crc = homeblocks_sig_compute_crc(&local);
if (expected_crc != local.hdr_crc) {
return HOMEBLOCKS_SIG_BAD_CRC;
}
if (out_sig) *out_sig = local;
return HOMEBLOCKS_SIG_OK;
}