Robert Allan James
36389e9d4a
Adds q48_reduce_angle() (range-reduce a signed Q48.16 angle into [-PI_Q48, PI_Q48] via one integer division plus a bounded fix-up loop) and q48_sin_approx/q48_cos_approx (Taylor series, terms n=3,5,7,9,11 for sin and n=2,4,6,8,10 for cos, early exit below 10). Q.SIN/Q.COS registered as FORTH words in q48_words.c, same pattern as Q.LOG/Q.EXP/Q.SQRT. Found mid-implementation: this codebase has two independent Q48.16 implementations -- src/word_source/q48_16_words.c (hosted/vendored) and src/starkernel/math/q48_16.c (kernel-only; the kernel build does not compile the former at all). The hosted build linked fine after the first pass; the kernel build failed with undefined references until the same two functions were added to both .c files and both q48_16.h headers (include/q48_16.h and include/starkernel/q48_16.h). Not fixed at the root -- Q.LOG/Q.EXP/Q.SQRT already had this same four-file duplication, unremarked until now -- just navigated correctly for this item. Verified live on amd64 via serial injection: sin/cos at 0, +-pi/2, pi, and 3pi (range-reduction across multiple turns) all match expected values within Taylor-series truncation error (<0.2%). All three architectures boot clean to ok> with the DoE completing; dict_hash identical across all three (0x291a660b05fa7b52). FABRIC.md item 4.3.3a marked done with full acceptance evidence.
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