Commit Graph
7 Commits
Author SHA1 Message Date
Daniel Samson e854f65623 docs: full docs-vs-code audit — fix every stale claim across 40 docs
Every doc verified claim-by-claim against the code by parallel audit agents,
then fixed and adversarially re-verified. Two waves of staleness corrected:
the originally audited findings (higher-half boot handoff, kernel VFS
takeover, fault isolation + claim release + driver restart, AML/S5 moving to
ring 3, threading's shipped design, USB+FAT landing) and a second pass of
adjacent claims the verifiers caught (smp.md 'not built yet' intro,
system-requirements' PS/2-only and no-storage claims, halting.md's red-panic
and no-IDT text, testing.md's serial mirroring, router-era vfs-protocol
wording, capsule-first boot loading).

threading.md now documents the shared-fate gap explicitly: the design says a
process dies whole, the kernel today kills only the offending thread.

Also fixes three stale code comments (isr.s exceptionHandler, acpi.zig
sleepValue, build.zig boot-volume) — comments only, no behavior change.
2026-07-22 09:09:53 +01:00
Daniel SamsonandClaude Haiku 4.5 f9dea7790a docs: rename arch.md to architecture.md and update all references
Rename the file to match current naming conventions and update all
cross-references throughout the documentation. Update the content to
reflect the current state of the codebase:

- Module is now called "architecture", not "arch"
- Directory is system/kernel/architecture/, not system/kernel/arch/
- Generic kernel file is kernel.zig, not main.zig
- Updated file listing for x86_64 architecture module (added smp.zig,
  per-cpu.zig, ioapic.zig, trampoline.s)
- Updated function list in cpu.zig to include enterUser/userExit and
  address-space management
- Clarified that _start lives in architecture-specific isr.s
- Expanded architecture-specific vs generic comparison table with
  actual current modules

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
2026-07-22 02:10:00 +01:00
Daniel Samson 452080e997 Add runtime.time, drop demo drivers, harden TSC timekeeping
Time is a kernel concern in danos: the kernel owns the scheduling timer and
already exposes monotonic time via the clock/sleep/timer_bind syscalls, so a
userspace time service would be a redundant, slower path. This adds the generic
runtime.time module over those syscalls, retires the two demonstration drivers,
reorganizes the milestone docs, and makes the monotonic clock correct on Intel,
AMD, and inside any VM.

runtime.time (library/runtime/time.zig)
- Instant/Duration interface: now, sleep, spin, after, monotonicNanos, available
- a thin layer over system.clock/sleep/timerOnce; unit-tested arithmetic

Remove the demo drivers hpet and bus (a teaching example belongs in the docs,
not shipped in the tree)
- system/drivers/ now holds only real drivers: pci-bus, ps2-bus, usb-xhci-bus
- device-manager end-to-end test repointed to pci-bus (asserts on kernel state:
  the process table and the device tree, not a racy serial marker)
- device_register containment moved to a new in-kernel `containment` test
- the driver-model worked example moved inline into docs/drivers.md

Reorganize milestone docs into topic docs
- m17-m18 / m19-m20 / m21 plans dissolved into process-lifecycle, device-manager,
  discovery, and acpi docs; new docs/power.md and docs/timers.md; ~20 citations
  repointed; plan docs deleted

TSC reliability (apic.zig, smp.zig, cpu.zig, kernel.zig)
- check the invariant-TSC bit (CPUID 0x80000007 EDX[8]) on Intel and AMD
- cross-core "warp" check at SMP bring-up, pairwise BSP<->AP as each core comes up
- fall back to the HPET clocksource when the TSC is not invariant (a bare VM) or
  not synchronized (a warp), switched continuously so time never jumps
- boot log reports the outcome; new tsc-sync test exercises the TSC + warp path

Verified: zig build; zig build test; 60/60 QEMU cases (incl. new containment and
tsc-sync).
2026-07-13 11:56:43 +01:00
Daniel Samson 0628944b15 Docs: close the discovery migration (M20.3)
discovery.md records ACPI enumeration leaving the kernel; device-manager.md
increment 8 marked done — enumeration now runs entirely in ring 3.
2026-07-13 03:32:53 +01:00
Daniel Samson af2c766f42 The flip: PCI enumeration leaves the kernel (M19.3)
enumeratePci, addBars, pciConfigurationPtr, and the PciHeader struct are
deleted; the kernel seeds only the host bridge, and the ring-3 pci-bus
driver's reports are the sole source of PCI function nodes. The manager
matches PCI drivers from reported identity, deduped by registered device
id so a bus restart never double-spawns.

The flip did its job by exposing a latent SMP race: ring-3
device_register made the broker table concurrent for the first time, and
mmio_map read it lock-free — under load a torn resource length mapped
hpet's window wrong (its user fault) and underflowed r.len-1 into a
kernel integer-overflow panic. Fixed: the broker read in mmio_map (and
claim) runs under the big kernel lock, the arithmetic rejects
zero-length and wrapping windows cleanly, and pci-bus no longer registers
unimplemented size-0 BARs. driver-restart hammered 6x, suite 55/55.
2026-07-13 02:54:50 +01:00
Daniel Samson 2ee898a91e add device platform module with ACPI support 2026-07-08 09:23:41 +01:00
daniel f9f0511ac2 documenting research for arm and device discovery 2026-07-03 20:22:48 +01:00