Syscall Reference

Syn_OS extends the Linux syscall table with 17 custom syscalls (469–485). All 17 are wired with full handlers, copy-to/from-user paths, LRU caches, ring buffers, eBPF monitor tables, and host tests.

The 50-syscall ceiling discussed in early FEV documents was an aspirational maximum. The practical scope landed at 17 covering all kernel-side observability + AI-cortex needs.

Consciousness fusion (469–479) — v41 Wave 8

Implemented in synos_syscall kernel module. Hold fragment_field.rs for 475/476/477.

#	Name	Returns / Effect
469	GET_CONSCIOUSNESS_STATE	struct consciousness_state — coherence, activity, mode, decision latency
470	PROCESS_AI_STIMULUS	Enqueues a stimulus into the fusion pipeline; returns request handle
471	MAKE_AI_DECISION	Synchronous fused decision over a posed problem; latency-bounded
472	UPDATE_AI_MEMORY	Append a MemoryFragment into hippocampus storage
473	GET_AI_METRICS	Decision counters + latency histogram
474	OPTIMIZE_MEMORY_LAYOUT	Apply fragment-aware allocator hints from synos-memory
475	GET_QUANTUM_STATE	Returns Fragment Field IDS energy signature
476	CREATE_MEM_ENTANGLE	Establish correlated memory regions for energy-topology IDS
477	GET_MEM_RECOMMEND	Allocator hints based on observed entanglement
478	ENABLE_EBPF_MONITOR	Toggle one of the 5 eBPF monitors (memory / network / process / security / perf)
479	GET_EBPF_STATS	Read eBPF monitor stats from kernel-side ring buffer

Glasswalker observability (480–485) — v45

Implemented in synos-observability-module (fruit/core/kernel/observability/). eBPF-friendly counters and perf ring buffers.

#	Name	Returns / Effect
480	OBS_REGISTER_COUNTER	Register a kernel-observability counter; returns counter ID
481	OBS_INCREMENT_COUNTER	Atomic counter increment from userspace context
482	OBS_READ_COUNTER	Read counter value
483	OBS_PERF_RING_OPEN	Open a perf ring buffer for high-throughput event streaming
484	OBS_PERF_RING_SUBMIT	Submit an event to the ring
485	OBS_PERF_RING_DRAIN	Userspace drain of accumulated events

Calling convention

Standard Linux x86_64 syscall ABI. Argument registers: rdi, rsi, rdx, r10, r8, r9. Return value in rax.

#include <syn_os/syscalls.h>     /* SYS_GET_CONSCIOUSNESS_STATE etc. */
#include <syn_os/types.h>

struct consciousness_state s;
long rc = syscall(SYS_GET_CONSCIOUSNESS_STATE, &s);
if (rc < 0) {
    /* errno set; ENOSYS if Curtain v3 tier denies the claim */
}

if (s.coherence > 0.85 && s.mode == ALFRED_MODE_ADVISORY) {
    struct ai_request  req  = { .kind = AI_DECISION_RECON, /* ... */ };
    struct ai_response resp = { 0 };
    syscall(SYS_MAKE_AI_DECISION, &req, &resp);
}

Tier gating

The Curtain v3 LSM hook intercepts each syscall and consults the calling process’s tier token before dispatching:

Syscall range	grimoire-public	goodlife	master
469	✅ allowed (read-only)	✅ allowed (read-only)	✅
470–474	❌ ENOSYS	✅ allowed (research-mode)	✅
475–477	⚠️ userspace-only path	✅ kernel + userspace	✅
478–479	✅ allowed	✅ allowed	✅
480–485	✅ allowed	✅ allowed	✅

Read more: Curtain Capability Tokens →

Header

The userspace header is shipped in the synos-headers package:

#include <syn_os/syscalls.h>   /* syscall numbers */
#include <syn_os/types.h>      /* consciousness_state, ai_request, etc. */
#include <syn_os/curtain.h>    /* tier-related typedefs */

Errors

errno	Meaning
ENOSYS	The syscall is denied by Curtain v3 for this tier (most common reason)
EPERM	The kernel taint flag is set; Master claims revoked
EAGAIN	The fusion pipeline is at capacity — back off and retry
EINVAL	Argument structure failed validation
EFAULT	copy_from_user / copy_to_user failed
ETIMEDOUT	Synchronous decision exceeded its latency budget

Reading the kernel side

/proc/synos/consciousness         # current ConsciousnessState (469 mirror)
/proc/synos/fragment-field        # Fragment Field IDS energy state (475 mirror)
/proc/synos/observability/*       # registered counters (480–482 mirror)
/proc/synos/attest/ledger         # HMAC-SHA256 attestation chain
dmesg | grep -i synos

Note

These syscalls are implemented via Rust kernel modules using the rust-for-linux framework. They are available only on Syn_OS kernels — calling them from a non-Syn_OS Linux installation will return ENOSYS from the upstream kernel.

Related

• Custom Kernel → — module architecture, eBPF monitors, LSM hook
• ALFRED → — the consciousness fusion engine that drives 469–474
• Curtain → — tier-based access control for syscalls