Robert Allan JamesandClaude Sonnet 5
1bd041e84d
Re-examined the Pi 5 RP1 PCIe access re-scoping (§IV.3 item 5) to see what
was actually buildable before real hardware arrives (2026-09-17), and
found nothing safely implementable this pass -- recorded three corrections:
1. The "vmm_map_range() needed for native boot" secondary finding is
wrong as stated: arch_mmu_init() is a stub on both non-amd64 ISAs,
vmm.c's load_cr3() is a no-op outside __x86_64__, and riscv64's satp
is explicitly left at Bare (this session's own §V.3 item 7 fix). No
non-amd64 ISA ever turns its own MMU on today, so VA==PA and there is
nothing to map. Reframed as a future concern conditional on MMU
bring-up, not a current prerequisite.
2. No silent-wrong-answer risk exists today: with no ACPI on native Pi 5
boot, pci_init()'s MCFG parse already fails cleanly and aarch64 takes
no ECAM fallback, rather than misreading RP1's 37 KB indirect window
as flat ECAM.
3. The "make config-space dispatch runtime instead of compile-time" half
of the re-scoped fix, considered on its own, isn't separable:
portio_read32() and siblings use outl/inl inline asm that cannot exist
in an aarch64/riscv64 translation unit, so any case referencing them
stays #ifdef-gated regardless -- an enum wearing the same compile-time
selection. It only becomes real dispatch once a second non-amd64
mechanism is actually compiled in.
Broadcom indirect access itself remains unimplemented: no QEMU model
exists for "brcm,bcm2712-pcie" (zero branches would ever execute before
real hardware, unlike the guard-exercised GIC/PLIC DTB fixes), and
config-space access alone is insufficient for RP1 to enumerate without
the real driver's controller bring-up (link training, PERST, window
setup) -- building only the index/data window would compile and boot
while silently never working.
No code changed. 3-arch acceptance run anyway per convention: all three
reach zuse)ok> with identical virtio-blk/xHCI PCI device discovery to
the pre-change baseline (commit 9b6de5d), confirming no regression from
a change that touched no source.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019YcT3H2PQeyujrzjqS3Var
capsules/
FORTH personality files loaded by the VM at boot. A capsule is an immutable, content-addressed payload; its XXHash64 hash is its identity. Any mutation changes the hash and the birth protocol rejects the image.
Key files
| File | Type | Purpose |
|---|---|---|
init.4th |
(m) MAMA_INIT |
Default Mama VM personality — loaded at LBN 2048 |
ACL.4th |
user | Word-level ACL system; self-activating at boot |
zuse.4th |
user | Bootstrap superuser; loaded by ACL.4th |
doe.4th |
user | DoE workload words (EXEC-DOE) — opt-in |
init-0.4th … init-9.4th |
(p) |
Numbered personality variants |
init-l8-*.4th |
(p) |
L8 Jacquard mode variants (stable/volatile/diverse/temporal/transition/omni) |
hermes/init.4th |
(p) |
Hermes baby VM personality |
artemis/init.4th |
(p) |
Artemis baby VM personality |
Block namespace
Block ranges are shared across all loaded capsules — collisions cause silent word-definition overwrites.
| Range | Owner |
|---|---|
| 2048–2099 | init.4th |
| 2100–2199 | doe.4th |
| 3000–3999 | workload capsules |
| 4000+ | user-defined (ACL.4th, zuse.4th, …) |
Each block is limited to 1024 bytes. Verify with wc -c before committing.
See also
experiments/bare_metal/README.md— DoE protocols and block namespace rulesdocs/03-architecture/word-acl/DESIGN.md— ACL system designtools/mkcapsule.c— assembles capsules intocapsule_generated.c- Project root