The module-to-domain table in build-support duplicated what each
domain's build.zig already states with its addModule exports. userBinary
now resolves each named import by searching the packages the binary
declared in its own build.zig.zon (b.available_deps), which also makes
the zon the literal include path: an import can only be satisfied by a
domain the binary claims, and naming a module whose domain is missing
fails the build graph with the domain to declare. build-support is down
to the recipe alone. All build variants green; manifest unchanged.
Every binary's build.zig now names precisely the modules its source
imports (derived by scanning each artifact's sources, transitively
through same-directory files), and its zon carries only the domains
those come from — kernel stays implicit (the root shim + link script
live there). build-support's userBinary resolves each name through one
module-to-domain table (module_homes); Domains/domains()/defaultImports
and the raw recipe entry point are deleted. An undeclared @import is a
compile error (verified: injecting @import("xkeyboard-config") into
logger fails with 'no module named ... available within module
program'), and e.g. xkeyboard-config now appears in exactly two
manifests — the two keyboard drivers. Availability never bloated the
emitted binaries (Zig compiles only what a program imports); this makes
the declared interfaces honest. Production and -Dtest-case manifests
byte-identical; all build variants and standalone package builds
green.
init, fat, display, display-demo, device-manager, input, logger, and
the two discovery fillers (acpi, fdt — each exporting an artifact named
"discovery"; the root -Ddiscovery picks which ships) convert to binary
packages on the pci-bus template. init's serial heartbeat flag rides
the dependency options (the root forwards its -Dserial). fat's and
display's unit tests move into their packages and the root aggregate
delegates to them. Boot-image file list 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.
Daniel Samson