Robert Allan JamesandClaude Sonnet 5
11c93773d0
Investigated before writing code, per this document's own discipline, and
found the original item 5 text's assumption doesn't hold: it framed this
as "swap the ACPI MCFG lookup for a DTB one, same flat-ECAM access
underneath." Confirmed against three primary sources that this is wrong:
- bcm2712-rpi-5-b.dts: RP1 sits under pcie2 ("brcm,bcm2712-pcie"),
reg = <0x10 0x00120000 0x00 0x9310> -- a ~37KB window, far too small
for a flat 256MB ECAM region.
- pcie-brcmstb.c (the real Linux driver for this compatible string):
brcm_pcie_map_bus() computes a standard ECAM-shaped offset but accesses
it through an IDX_ADDR/DATA_ADDR indirect index+window pair, not a
direct MMIO read. A real third config-access mechanism, not a bigger
version of the DTB-lookup task.
Re-scoped item 5 (§IV.3) to record the real shape: pci.c's cfg_read32/
cfg_write32 family dispatches today via #ifdef ARCH_AMD64 vs. everything
else (flat ECAM) -- but QEMU aarch64 (flat ECAM, real ACPI MCFG) and Pi 5
aarch64 (Broadcom indirect windowing) are the same build, so this needs a
runtime dispatch change to a file all three architectures currently boot
through, not a small addition. Also flagged: pci_init()'s vmm_map_range()
for the ECAM window is amd64-only today (aarch64/riscv64 rely on UEFI's
identity map); native boot has no UEFI identity map at all, so any PCIe
work here needs its own explicit mapping regardless of access mechanism.
Also corrected §V.3 item 5's now-stale "shares the same code" cross-
reference -- the Mars's JH7110 PCIe controller needs its own primary-
source check, not an assumed-shared implementation with RP1's.
Not implemented this pass -- recording the real shape is the deliverable;
building the runtime-dispatch version is a materially larger, separate
task. Doc-only change; 3-arch boot verified per the project's standing
rule, proving only that nothing regressed.
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