Daniel Samson
be81394be3
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.
53 lines
2.3 KiB
Zig
53 lines
2.3 KiB
Zig
//! Raw `system_call` instruction wrappers for user space — one per arity.
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//!
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//! ABI: number in rax, arguments in rdi, rsi, rdx, r10, r8, r9, result in rax.
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//! The `system_call` instruction itself clobbers rcx (it holds the return rip) and
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//! r11 (the saved rflags); the kernel entry stub preserves everything else.
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//! Note argument #3 goes in **r10, not rcx** — rcx is unavailable across the
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//! instruction, so the kernel reads the 4th argument from r10.
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const abi = @import("abi");
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const SystemCall = abi.SystemCall;
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pub inline fn systemCall0(n: SystemCall) usize {
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return asm volatile ("syscall"
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: [ret] "={rax}" (-> usize),
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: [n] "{rax}" (@intFromEnum(n)),
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: .{ .rcx = true, .r11 = true, .memory = true });
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}
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pub inline fn systemCall1(n: SystemCall, a0: usize) usize {
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return asm volatile ("syscall"
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: [ret] "={rax}" (-> usize),
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: [n] "{rax}" (@intFromEnum(n)), [a0] "{rdi}" (a0),
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: .{ .rcx = true, .r11 = true, .memory = true });
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}
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pub inline fn systemCall2(n: SystemCall, a0: usize, a1: usize) usize {
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return asm volatile ("syscall"
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: [ret] "={rax}" (-> usize),
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: [n] "{rax}" (@intFromEnum(n)), [a0] "{rdi}" (a0), [a1] "{rsi}" (a1),
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: .{ .rcx = true, .r11 = true, .memory = true });
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}
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pub inline fn systemCall3(n: SystemCall, a0: usize, a1: usize, a2: usize) usize {
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return asm volatile ("syscall"
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: [ret] "={rax}" (-> usize),
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: [n] "{rax}" (@intFromEnum(n)), [a0] "{rdi}" (a0), [a1] "{rsi}" (a1), [a2] "{rdx}" (a2),
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: .{ .rcx = true, .r11 = true, .memory = true });
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}
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pub inline fn systemCall4(n: SystemCall, a0: usize, a1: usize, a2: usize, a3: usize) usize {
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return asm volatile ("syscall"
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: [ret] "={rax}" (-> usize),
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: [n] "{rax}" (@intFromEnum(n)), [a0] "{rdi}" (a0), [a1] "{rsi}" (a1), [a2] "{rdx}" (a2), [a3] "{r10}" (a3),
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: .{ .rcx = true, .r11 = true, .memory = true });
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}
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pub inline fn systemCall5(n: SystemCall, a0: usize, a1: usize, a2: usize, a3: usize, a4: usize) usize {
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return asm volatile ("syscall"
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: [ret] "={rax}" (-> usize),
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: [n] "{rax}" (@intFromEnum(n)), [a0] "{rdi}" (a0), [a1] "{rsi}" (a1), [a2] "{rdx}" (a2), [a3] "{r10}" (a3), [a4] "{r8}" (a4),
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: .{ .rcx = true, .r11 = true, .memory = true });
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}
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