Robert Allan JamesandClaude Sonnet 5
af267a52a6
blk_subsys_detach_device() (block_subsystem.c) walks the device chain, refuses removal of anything but the current tail (a mid-chain removal would corrupt every later slot's start_lbn -- this architecture's own doc already argues USB stays last specifically to avoid that), unlinks, shrinks total_user_lbn, closes and frees the slot. Discards rather than flushes dirty state -- the device is physically gone by the time this runs (PORTSC disconnect only). Trigger wiring mirrors the attach path: bot_msc_attached (set only once attach actually succeeds) gates a new bot_msc_detach_pending flag set at PORTSC disconnect (not Disable Slot completion, which is conditionally skipped and would miss concurrent connect/disconnect pairs), consumed in sk_repl_idle(). Advisor flagged the real hazard ahead of time: block_words.c's VM block window (blk_vm_lbn[]/blk_vm_cbuf[]) can go stale across a detach then a same-LBN re-attach, and suggested a pointer-identity re-check in blk_vm_load() as a minimal fix. That fix was implemented, then directly falsified by its own designed-for-this test: attach a blank device, read a block (populating the cache), detach, re-attach a device with distinct content at the identical LBN, read again -- served stale content from the first device. Root cause, confirmed live: glibc's allocator hands free(slot) straight back to the very next same-size calloc(), so the "fresh" and stale pointers were bitwise identical despite being two different devices. Fixed properly with a monotonic blk_subsys_epoch() counter (bumped on every attach/detach) checked by a new blk_vm_check_epoch() helper at the one choke point (blk_vm_find(), plus blk_vm_flush_all() which reads the same arrays directly) that covers every path touching the window cache -- unfooled by address reuse. Verified live with a new disk/usb-thumbdrive-test2.img fixture (distinct content from the existing blank test image): attach A, read (cache hit populated), detach, re-attach B at the same LBN, read again -- correctly ran a fresh device read and returned B's real content, not A's stale cached zeros. The failing pointer-comparison attempt's own capture log kept as evidence, not deleted. All three architectures re-verified clean. FABRIC-2.md Section X 2h marked complete -- enumeration through hot-detach all live and verified; only WRITE(10) (2g's own still-open item) remains unimplemented in the driver, not blocking anything here. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01CXjAPTEKrgY2Mrk25KoLDn
lfs/
Per-architecture copies of the hosted starforth binary. The hosted
Makefile copies the freshly built binary here as its last build step
(cp $(BINARY) lfs/$(ARCH_DIR)/starforth), separate from
build/<arch>/<profile>/, which is the working build-output tree.
amd64/starforth,arm64/starforth,riscv64/starforth— one binary per architecture, rebuilt whenever that architecture's hosted build runs.