Daniel Samson
8754d4e46a
The source layout now mirrors the runtime filesystem hierarchy
(docs/danos-file-system-hierarchy-FSH.md): what lives under system/ in the
source is what a running danos represents under /system. Each service and
driver is a sub-project directory that is its own Zig module — cross-project
references go by module name, never by a path into another project's files.
Moves (all git mv, history preserved):
- src/ -> system/ (danos internals; the self-representation)
root.zig -> danos.zig (the kernel<->user contract module)
kernel/arch/ -> kernel/architecture/ (arch -> architecture)
device/ -> devices/ (what /system/devices reflects)
boot/ -> /boot (the loaders, top level)
- sbin/ -> split by role:
init, vfs -> system/services/<name>/<name>.zig
hpetd, busd -> system/drivers/<name>/<name>.zig
vfs-test -> system/services/vfs/vfs-test.zig (inside the vfs project)
- lib/ -> library/runtime/ (room for other libraries beside runtime)
The VFS wire protocol becomes its own module, system/services/vfs/protocol.zig
("vfs-protocol"): the vfs sub-project exposes its interface, and the runtime's
file layer imports it by name. First instance of the "protocol module" pattern
(docs/driver-model.md); usb/block will expose theirs the same way.
Also: fix a naming-standard violation in the protocol — Op -> Operation (and
req -> request, _pad -> _padding). Docs updated: /system/services added to the
FHS doc, a repository-layout section added to the docs index, and stale source
paths swept across comments and docs.
Runtime boot paths are unchanged (the bootloader still loads /sbin/init);
aligning the runtime filesystem to the FHS is a separate follow-up. Suite 35/35
plus host tests green.
40 lines
1.8 KiB
Zig
40 lines
1.8 KiB
Zig
//! /sbin/init — the first user-space program, PID 1. Built as its own
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//! freestanding binary (see build.zig), shipped on the boot volume at sbin/init,
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//! loaded by the bootloader, and started in ring 3 as a scheduled process by the
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//! kernel (system/kernel/process.zig). It links against the shared user runtime
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//! library `runtime` and talks to the kernel only through `runtime`'s system_call wrappers.
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//!
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//! Today it proves the C-convention heap works, then settles into a heartbeat:
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//! it prints a line and sleeps, forever — enough to show the system reaches user
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//! space and stays alive with a real process scheduled alongside the kernel's
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//! idle loop. It grows into the real init (service supervision) once there are
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//! other user programs to supervise.
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const runtime = @import("runtime");
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pub fn main() void {
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// Prove the heap end to end: allocate through the runtime allocator (which
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// mmaps pages from the kernel and carves them with the free list), write into
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// that heap buffer (exercising the widened debug_write bounds check), and
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// free it. A fault here would kill init before it heartbeats — so the init
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// test doubles as the heap regression test. (C code links the same heap via
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// the extern malloc/free symbols; Zig code uses this allocator.)
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const gpa = runtime.allocator();
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if (gpa.alloc(u8, 64)) |buffer| {
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const message = "init: heap ok\n";
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@memcpy(buffer[0..message.len], message);
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_ = runtime.system.write(buffer[0..message.len]);
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gpa.free(buffer);
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} else |_| {}
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while (true) {
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_ = runtime.system.write("init: heartbeat\n");
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runtime.system.sleep(1000);
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}
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}
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pub const panic = runtime.panic;
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comptime {
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_ = &runtime.start._start; // pull the runtime entry shim into the image
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}
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