Addresses items #1 (partial) and #2 of
docs/working/archive/session-logs/2026-07-24-punch-list.md.
docs/lithosananke/hosted-acceptance-test/README.md:
- riscv64 leg used riscv64-linux-gnu-gcc, which fails to build this tree
(nanosleep visibility under -std=c99). Replaced with the working
clang-18 --target=riscv64-linux-gnu --sysroot=/usr/riscv64-linux-gnu
invocation, verified end-to-end.
- All three arch sections referenced a -c "<script>" flag that has never
existed in cli.c/main.c. Corrected to the working
`echo "..." | starforth -s` pattern, verified on all three architectures.
- Updated Prerequisites: qemu-user alone is sufficient (guest binaries are
static; qemu-user-static provides static *emulators*, not required here).
Source fixes (ported from the old pre-split monorepo's master, commit
4db9946a, where they were made but never carried over to this line):
- src/math_portable.c: `-100LL << 16` is UB (shifting a negative value)
under clang's -Wshift-negative-value; changed to `-(100LL << 16)`.
- src/physics_pipelining_metrics.c: removed dead q48_mul_q48()
(-Wunused-function under clang; GCC doesn't flag this by default).
- src/word_source/editor_words.c: removed dead set_scr() (same reason).
These three were required just to get the documented clang build to
compile at all. The punch list's higher-severity item — a genuine
SIGSEGV-causing register-reuse hazard in vm_pop_asm/vm_rpop_asm
(include/vm_asm_opt_riscv64.h) — is intentionally NOT included here; it's
a separate, more careful change and isn't required for this build to
succeed (latent only under clang; this repo's kernel build uses GCC).
Verified: all three hosted builds compile and run correctly (amd64
native, aarch64 via qemu-aarch64, riscv64 via qemu-riscv64), each
printing "3 Goodbye!" for the piped `1 2 + . BYE` script. All three
Makefile.starkernel builds (amd64/aarch64/riscv64) still compile cleanly
with these shared vendored-source changes.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
kernel_main on riscv64 ran directly on EDK2's UEFI boot-time stack, with
no dedicated stack switch — amd64 has always had a kernel_entry.S
trampoline for exactly this reason (its own comment: "the FORTH
interpreter + DOE experiment loop can easily exceed that depth").
aarch64 happens to get away without one because its firmware's default
stack is apparently larger, but that was never a guarantee.
On riscv64 the VM bootstrap's call depth (27 word-registration modules
-> physics/SSM init -> Tripod capsule birth) overflowed that small
stack, corrupting a return address and producing a wild jump / page
fault right after vm_init_with_host() returned — reproduced consistently
across the 2026-08-01 DoE campaign logs.
- src/starkernel/arch/riscv64/kernel_entry.S (new): RISC-V stack-switch
trampoline mirroring amd64's, giving the kernel a dedicated 2 MiB BSS
stack before anything deep runs.
- kernel_main.c: riscv64 now builds kernel_main_impl (invoked via the
trampoline) instead of kernel_main directly, same pattern as amd64.
- Makefile.starkernel: wires the new file into the riscv64 build.
- uefi_loader.c: RAW_LOG() was silently a no-op on every non-amd64 arch;
added a real raw-UART writer for riscv64 (QEMU virt's uart8250 at MMIO
0x10000000) so existing loader diagnostics actually produce output.
Verified: all three architectures boot clean to [Hera] ok> in the
required order (amd64, aarch64, riscv64); logs and DoE CSVs from these
runs included.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
