/etc/init.csv and /etc/devices.csv become /system/configuration/*.csv (the
repo's etc/ moves to system/configuration/, mirroring the runtime tree),
/var/log becomes /system/logs, and /mnt/usb becomes /volumes/usb. The
kernel VFS gains a carve-out so FAT may serve exactly /system/configuration
and /system/logs beneath the initrd-backed /system while /system and /test
themselves stay unshadowable; FAT's single /var mount splits into those two
rewritten mounts. The kvfs readdir check learns /system's third child and
the ramdisk spawn sweep skips the configuration tree.
Suite 106/106.
Each library domain (kernel, device, client, protocol, csv,
xkeyboard-config) now owns a build.zig + build.zig.zon that wires and
exports its modules, with a standalone `zig build test` per domain.
The kernel package also exports abi (source stays in system/abi.zig) so
every consumer names one module instance. The root build swaps its
createModule calls for b.dependency(...).module(...) — no binary moves;
the root is the pilot consumer (docs/build-packages-plan.md). Path
dependencies deduplicate by resolved location, so the diamond
(root -> device -> kernel, root -> kernel) yields a single instance of
each module. Boot-image file list unchanged.
Replaces L2's interim DMA pool (every buffer reachable by every claimed
device) with true per-grant confinement: a device reaches only buffers
whose capability was delegated to its driver.
Kernel:
- DmaRegionObject (handle kind 2): a delegation token naming a dma_alloc'd
region, passable across processes on the IPC cap slot like an endpoint
or shared-memory object. Frames stay owned by the allocating address
space (freed on dma_free/teardown as before); the token carries a `dead`
flag so a stale downstream handle can no longer bind a freed region.
- dma_alloc gains the dma_shareable flag: it returns a capability handle
in r8 and every region is tracked in a registry. A task's own regions
auto-bind into the devices it claims (its rings just work); foreign
buffers are bound explicitly.
- dma_bind / dma_unbind / handle_close syscalls (51-53). dma_bind maps a
held region (or shared-memory) capability into a claimed device's domain;
it is idempotent. handle_close reclaims a table slot (raised 16 -> 32).
- dma_free and task death unmap a region from every domain and invalidate
BEFORE its frames return to the allocator — the stale-IOTLB use-after-
free window, closed structurally.
Protocols (flag-day): block gains attach, usb-transfer gains dma_attach —
each carries a region capability on the cap slot. fat allocates its bounce
buffer shareable and attaches it; usb-storage allocates its transport
buffers shareable, attaches them to the controller, and forwards fat's
capability downstream; usb-xhci-bus binds and closes; virtio-gpu binds its
shared scanout surface. The physical addresses on the wire are unchanged
(identity IOVA), so no register-programming code moved.
Cross-process DMA (fat -> usb-storage -> xHC) now flows only through
delegated capabilities. iommu-usb-storage / iommu-usb-hid / iommu-fault
all green under per-grant enforcement; 104/104 overall (fail-open paths
unchanged).
Replaces L1's shared blanket identity domain with a private translation
domain per claimed PCI function. A device now reaches only:
- the DMA pool: every dma_alloc'd region, mapped into every claimed
device's domain (poolAdd/poolRemove, driven from the dma_alloc and
dma_free syscalls). This keeps the cross-process buffer handoff
working (fat's bounce buffer reaches the xHC) while blocking the
kernel, page tables, process heaps, MMIO, and unallocated RAM.
- its own firmware reserved region (RMRR), seeded at confine time.
The pool is the honest interim: devices can still reach one another's
DMA buffers. The DMA-region capability layer (next) narrows it to
per-grant reachability.
dma_free unmaps from every domain and invalidates BEFORE the frames
return to the allocator, closing the stale-IOTLB use-after-free window.
Driver death tears down its domains (detach + free tables) before the
broker claims and DMA frames are released.
New iommu_fault_drain syscall (+ driver.iommuFaultDrain) forces pending
fault records to the log on demand. The new iommu-fault case proves it:
a claimed e1000e is programmed to DMA-fetch its TX ring from an unmapped
page; VT-d faults the access (bdf 00:03.0 addr 0x1000 reason 0x6) and the
system stays alive. 104/104.
library/device/pci is now the complete generic floor a leaf PCI driver
needs, instead of just what virtio-gpu used:
- pci-class: capability IDs, MSI/MSI-X/power-management/PCI-Express
register layouts, extended-capability header decode (host-tested),
per-bit command constants, remaining header offsets.
- pci.Function: header accessors, disableBusMaster + interrupt-disable
helpers, findCapability, programMsi/disableMsi, MsiX vector-table
struct, ensurePowerStateD0, functionLevelReset (BAR save/restore),
extended-capability iterator.
Proven by the new pci-caps QEMU case: a pci-cap-test fixture claims an
extra e1000e (PM+MSI+PCIe+MSI-X, no danos driver) and readback-verifies
every surface, including the first driver-side use of msi_bind.
usb-xhci-bus converts from 8 ms event-ring polling to message-signalled
interrupts: plain MSI where offered (real Intel xHC), MSI-X entry 0
otherwise (qemu-xhci has no MSI capability), byte-identical polling as
fallback. The timer survives as a 250 ms port-reconcile/lost-edge tick —
real-hardware USB2 hub debounce still needs it. MSI setup runs BEFORE
controller bring-up: QEMU's xhci only registers the MSI-X vector as used
when IMAN.IE is written while MSI-X is already enabled; interrupts are
silently dropped otherwise (real hardware does not care about the order).
101/101 QEMU cases green; real-hardware smoke passed (mouse works,
boot 2026-07-23T174805Z, plain-MSI branch, vector 33).
Replace init's hardcoded boot_services array with an authoritative,
human-readable service list read at boot, mirroring /etc/devices.csv. Each row
is a service binary path followed by its argv; startup order is file order,
shutdown the reverse. There is no hardcoded fallback — a missing file starts
nothing (the no-ramdisk isolation behavior).
- library/csv: shared CSV helpers (comment strip, field iteration) with unit
tests; device-registry is refactored onto them so both /etc/*.csv files parse
through one place.
- init reads /etc/init.csv into fixed-max static tables (the same pattern as the
device registry) and passes each row's argv straight to spawnSupervised. This
also makes boot-time modes (e.g. device-manager test-usb-restart) expressible
as data rather than hardcoded.
- Diagnose mode (-Ddiagnose omits the display stack) becomes build-time file
selection between etc/init.csv and etc/init-diagnose.csv, so init carries no
comptime service logic; the diagnose build option is dropped from init.
- build.zig: csv module wired; /etc/init.csv bundled into the initrd; the
device-registry tests move to a dedicated block since they now import csv.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KJqSiLLchDUUCoXn5jsiwd
Replace the three hardcoded switch tables (pciDriverForIdentity, hidDriverFor,
usbDriverForIdentity) with an authoritative, human-readable device registry the
manager reads at boot. Matching is most-specific-wins across
base/subclass/prog_if/vendor/device/subsystem/hid, so a precise vendor:device
rule and a generic class rule coexist; an unmatched device is logged, never
guessed. This resolves docs' "matching stays code until the third bus".
- ABI: child_added and DeviceDescriptor gain vendor/device/subsystem; child_added
gains a bus discriminator (BusKind) so PCI and USB class triples match against
the right namespace.
- pci-bus reads vendor/device (config 0x00) and subsystem (0x2C, type-0) and
reports them.
- library/device/registry: freestanding CSV parser + matchDriver() with
specificity scoring; 5 unit tests wired into `zig build test`.
- etc/devices.csv bundled into the initrd; the kernel serves /etc directly, so
the manager reads it before any filesystem service is up (fat starts later).
- virtio-gpu: drop the now-redundant post-spawn 1AF4:1050 re-confirm, since the
registry binds this driver by exact identity.
- Remove the orphaned system/drivers/display driver (unreferenced by build or
registry).
- docs: new devices-csv.md; device-manager.md "matching stays code" resolved.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KJqSiLLchDUUCoXn5jsiwd
Every user binary and the two device-logic library modules (pci, usb) now
`@import` the concern modules directly instead of aliasing through `runtime`:
runtime.ipc/process/time/service/input/block/display -> @import("<module>")
runtime.device / runtime.device_manager -> @import("driver")
runtime.fs -> @import("file-system")
runtime.Thread -> @import("thread").Thread
runtime.system.{write,writeRecord,klog*} -> logging.*
runtime.system.{sleep,timerOnce,wallClock,clock} -> time.*
runtime.system.{spawn*,kill,exit,yield,processes,...}-> process.*
runtime.system.{mmap,munmap,PROT_*} -> memory.*
runtime.dma.* / runtime.shared_memory.* / runtime.allocator -> memory.*
Each consumer keeps its own alias name (e.g. `const device = @import("driver")`),
so call sites are unchanged and there are no collisions with local `driver`
variables. build.zig now injects the concern modules into every user binary via
`default_imports`; pci/usb module import lists were updated to match.
The `runtime` and `system` shims remain for one more step (root.zig still uses
runtime); they are deleted in C5. Nothing but root.zig imports `runtime` now.
Verified: zig build, zig build test, and 17 QEMU cases (smoke, device-manager,
logger, fat-mount, fat-mutations, usb-storage, usb-hid, display-native,
virtio-gpu, input, thread-spawn, thread-mutex, process-kill, shared-memory,
driver-restart, acpi-ps2, pci-scan).
Follow-up cleanup of the just-moved kernel device code:
- power.zig -> acpi.zig. Its reboot() is built entirely on the FADT reset
register (acpi.power_information) plus the legacy 0xCF9/8042 fallbacks — it is
ACPI reboot, so it becomes acpi.reboot (the "P" in ACPI). platform.reboot
still delegates; soft-off/S5 stays the ring-3 acpi service's job as before.
- device-tree.zig -> fdt.zig. It is a discovery *backend* (the ARM/FDT parser,
a sibling of acpi.zig), not part of the model — renaming it to its actual
subject kills the confusing device-tree / device-model DeviceTree name clash
and makes acpi.zig + fdt.zig read as the two parallel backends.
- Flatten: device-model.zig, acpi.zig, fdt.zig, platform.zig move out of the
system/kernel/devices/ subdir up into system/kernel/, joining devices-broker.zig
(already flat). The kernel dir is a flat pile by convention (only architecture/
is a subdir), so the subdir — and its poor "devices" name — is gone.
Pure restructure; "platform" module name unchanged, all cross-file deps are
relative siblings that moved together. zig build + test green; smoke, discovery,
acpi-parse, acpi-ps2, acpi-report, power-button, orderly-shutdown, reboot pass.
With the shared device data (device-abi, pci-class, usb-abi, usb-ids, acpi-ids,
aml) now in library/device/, what remained in system/devices/ was purely
kernel-internal: the firmware-discovery machinery and the rich pointer-based
device model (platform, device-model, acpi, device-tree, power), reached only
through the "platform" module by three kernel files. It belongs with the kernel.
Move it to system/kernel/devices/. A pure relocation: the "platform" module
name is unchanged and every cross-dir dependency is a module import, so only the
one b.path and some comments move. The top-level split is now clean —
system/kernel/ is the kernel, library/device/ the shared device libraries,
system/{drivers,services} the userspace. The runtime /system/devices concept
(the virtual device tree) is unaffected; system/kernel/devices/ is its
implementation.
Also fixes two comment refs that still pointed device-abi at its pre-Wave-1a
home (system/devices/) — it lives at library/device/model/ now.
zig build + test green; smoke, discovery, acpi-parse, acpi-ps2, acpi-report pass.
mmio is device-driver code, so it joins the other domains under
library/device/mmio/ (module name "mmio" unchanged — a pure relocation, only
the build paths move). And its abbreviated function names are spelled out per
docs/coding-standards.md:
read -> readRegister mb -> memoryBarrier
write -> writeRegister rmb -> readMemoryBarrier
wmb -> writeMemoryBarrier
All call sites updated (virtio-gpu, usb-xhci-library, pci.Function); the two
display-driver placeholders import mmio but use nothing, so they're untouched.
Docs (driver-model graph, README layout, drivers.md, the FHS note) follow the
new path and names.
zig build + test green; virtio-gpu, display-native, display-reattach, usb-hid,
usb-hub, usb-storage, pci-scan pass.
Finish the direct-import convention: a protocol is now aliased to its module
name in snake_case in every file that imports one — consumers and the runtime
client wrappers alike. This kills the last of the alias variety (the generic
`protocol`, plus `power` and `transfer`), so `device_manager_protocol.Hello`
means the same thing everywhere and grepping a module name finds all its uses.
Pure rename (identifier uses only; prose references left untouched via a
guarded pattern). 14 files, 299/299 lines.
zig build + test green; 16 QEMU cases pass (smoke, device-manager,
driver-restart, device-list, pci-scan, usb-hid, usb-storage, display-service,
display-native, display-reattach, input, acpi-ps2, vfs, fat-mount,
power-button, orderly-shutdown).
The USB class-driver transfer client was library/runtime/usb.zig, re-exported
as runtime.usb — which compiled the USB client and usb-transfer-protocol into
every user binary (init, fat, the compositor…), none of which speak USB. It is
bus-family logic, not core runtime.
Move it to its domain home, library/device/usb/usb.zig (module "usb"), alongside
the usb-abi and usb-ids data modules; fix its internal imports to go through the
runtime module; and re-export usb.abi / usb.ids so a class driver reaches the
whole USB domain through one import. runtime.usb and runtime's
usb-transfer-protocol import are removed; the three class drivers
(usb-hid keyboard/mouse, usb-storage) import module "usb" directly.
zig build + test green; usb-hid, usb-storage pass.
New pci logic module (library/device/pci/pci.zig): a device driver's view of
the one PCI function it has claimed — Function.map (config space = resource 0),
vendorId/deviceId/command/status, enableMemoryAndBusMaster, mapBar (BAR decode
+ resource correlation + mmio_map, cached), and a capabilities() iterator. The
generic PCI mechanics every leaf PCI driver used to re-derive inline.
The config-space layout it needs — header offsets, the command MEM|bus-master
bits, the status capabilities-list bit, the capability-pointer mask, and the
BAR bit fields — is named in the pci-class data module (a "Configuration-space
layout" section), so the bus enumerator can share the same constants later.
virtio-gpu is the first consumer: its inline mapBar + walkCapabilities + config
header reads are gone, replaced by pci.Function; only the virtio-specific
cfg_type dispatch (and the virtio common-config cfgRead/cfgWrite, which are NOT
PCI config space) stay in the driver. The generic display driver will use the
same module. pci-bus's enumerator (arbitrary-function probing) is untouched.
zig build + test green; virtio-gpu, display-native, display-reattach, pci-scan pass.
First step of the device-code reorganization (plan: group device code by
domain, split each domain into a shareable data module + a logic module).
This moves the pure-data modules — the enums, wire types, and taxonomies
that any layer including the kernel can import cheaply — out of
system/devices/ and into their domain home:
device-abi -> library/device/model/device-abi.zig
pci-class -> library/device/pci/pci-class.zig
usb-abi -> library/device/usb/usb-abi.zig
usb-ids -> library/device/usb/usb-ids.zig
acpi-ids -> library/device/acpi/acpi-ids.zig
aml/ -> library/device/acpi/aml/
Module names are unchanged, so this is a pure file move: only the
b.addModule paths and the host-test file list in build.zig change; no
importer is touched. system/devices/ now holds only the kernel-internal
device model (device-model, platform, acpi, device-tree, power).
The device *logic* (the pci Function helper, the usb transfer client) and
the kernel's cosmetic taxonomy dependency are handled in following commits.
zig build + zig build test green.
Daniel Samson
Daniel Samson