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Split the system contract into boot-handoff / abi / device-abi

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The `system` module (formerly `danos`) had become a grab-bag: it held the
loader<->kernel handoff *and* the kernel<->user ABI *and* the device wire types, in
one module three different audiences imported. Usage proved the seam — the
bootloader never touched the syscall/device ABI, and user space never touched the
boot handoff — so split it by audience, one module per contract:

  system/boot-handoff.zig       loader <-> kernel: BootInformation, Framebuffer,
                                MemoryMap, the VM layout + physicalToVirtual, kernel_abi
  system/abi.zig                kernel <-> user, core: SystemCall, mmap prot flags,
                                page_size, notify_badge_bit, ServiceId
  system/devices/device-abi.zig kernel <-> user, devices: DeviceDescriptor,
                                DeviceClass, ResourceDescriptor, ResourceKind, ...

device-abi is the devices sub-project's public interface, exposed as its own module
the way vfs exposes vfs-protocol — importable by user space, unlike the
kernel-internal device model it also feeds. That collapses a real duplication:
DeviceClass and ResourceKind were defined twice (device-model.zig and the contract,
kept "in sync by hand"); device-model now re-exports them from device-abi, so the
enum a driver matches on and the one the kernel classifies with are one type.

Each import now declares which contract it speaks: the bootloader imports only
boot-handoff; a driver only abi + device-abi (via the runtime); the kernel all
three. This also retires the `system` / `runtime.system` name overlap. page_size
lands in abi (it's part of the mmap contract user space aligns to); the bootloader
keeps its own local 4 KiB constant so it depends on nothing but the handoff.

All 21 importers rewired, docs updated to keep /system mapping to source. Build,
host tests, and the QEMU suite (36/36) all green.
This commit is contained in:
Daniel Samson
2026-07-10 18:08:51 +01:00
parent 47610e8ee2
commit be81394be3
37 changed files with 395 additions and 337 deletions
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library/runtime/device.zig
+6 -6
View File
@@ -3,13 +3,13 @@
//! ownership of its hardware; the claim is the capability the kernel checks before
//! mapping registers or routing an IRQ.
const system = @import("system");
const device_abi = @import("device-abi");
const sc = @import("system-call.zig");
pub const DeviceDescriptor = system.DeviceDescriptor;
pub const ResourceDescriptor = system.ResourceDescriptor;
pub const DeviceClass = system.DeviceClass;
pub const ResourceKind = system.ResourceKind;
pub const DeviceDescriptor = device_abi.DeviceDescriptor;
pub const ResourceDescriptor = device_abi.ResourceDescriptor;
pub const DeviceClass = device_abi.DeviceClass;
pub const ResourceKind = device_abi.ResourceKind;
inline fn failed(r: usize) bool {
return r > ~@as(usize, 0) - 4095;
@@ -33,7 +33,7 @@ pub fn mmioMap(device_id: u64, resource_index: u64) ?usize {
}
/// `DeviceDescriptor.parent` for a device with no parent.
pub const no_parent = system.no_parent;
pub const no_parent = device_abi.no_parent;
/// Publish `descriptor` as a child of `parent_id`, which this process must have claimed.
/// Returns the new device id. The child is left unclaimed, so whichever driver owns