Daniel Samson
ceacc6b514
Follow-up to the monorepo re-org. Suite 35/35 plus host tests green. POSIX compatibility is now its own library, library/posix/ (unistd, stdio), layered strictly over the runtime — it calls the runtime's IPC/heap, never system calls directly. The runtime is now POSIX-free (the danos-native application ABI). The VFS wire protocol is danos-native throughout (Stat -> FileStatus, .stat -> .status, O_CREAT -> create); the POSIX layer maps the POSIX spellings at the boundary. The coding standard's ABI-name exception is scoped to one place: a file is allowed POSIX spellings only if it lives under library/posix/ — everywhere else, danos naming with no exception. Naming fixes, all mechanical: - initrd -> initial-ramdisk: the source file, the module, the tool (make-initial-ramdisk.py), the artifact (initial-ramdisk.img, including the bootloader's load path), and the identifiers. - system/kernel/device-service.zig -> devices-broker.zig: it is ring-0 kernel code (the trusted device table + claim capability), not a ring-3 service. The future user-space device *manager* (policy) will live in system/services/. - Dropped the daemon `d` suffix: hpetd -> hpet, busd -> bus. A driver lives in system/drivers/, so the folder already says what it is; encoding the role in the name too is redundant. The coding standard drops that exception. - system/devices/aml/interp.zig -> interpreter.zig (the type was already Interpreter).
59 lines
2.4 KiB
Zig
59 lines
2.4 KiB
Zig
//! The initial_ramdisk (initial ramdisk) container format — shared by the build-time
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//! packer (tools/make-initial-ramdisk.py) and the kernel that unpacks it. Deliberately
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//! trivial: a header, a table of fixed-size entries, then the concatenated file
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//! blobs. We own both producer and consumer, so it need be no fancier.
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//!
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//! Layout:
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//! Header (magic, count)
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//! Entry * count (name, offset, len) — offset/len into the image
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//! blob bytes... (each entry's file, at its offset)
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const std = @import("std");
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/// "DNRD" — identifies a danos initial_ramdisk image.
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pub const magic: u32 = 0x444E5244;
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pub const Header = extern struct {
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magic: u32,
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count: u32,
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};
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pub const Entry = extern struct {
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name: [32]u8, // NUL-padded file name (basename)
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offset: u64, // byte offset of the blob within the image
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len: u64, // blob length in bytes
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};
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/// A validated view over an initial_ramdisk image. `init` checks the magic and that the
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/// entry table fits; `entry` bounds-checks each blob against the image.
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pub const Reader = struct {
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image: []const u8,
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count: u32,
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pub fn init(image: []const u8) ?Reader {
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if (image.len < @sizeOf(Header)) return null;
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const h = std.mem.bytesToValue(Header, image[0..@sizeOf(Header)]);
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if (h.magic != magic) return null;
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const table_end = @sizeOf(Header) + @as(usize, h.count) * @sizeOf(Entry);
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if (table_end > image.len) return null;
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return .{ .image = image, .count = h.count };
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}
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pub const Item = struct { name: []const u8, blob: []const u8 };
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pub fn entry(self: Reader, i: u32) ?Item {
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if (i >= self.count) return null;
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const off = @sizeOf(Header) + @as(usize, i) * @sizeOf(Entry);
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const e = std.mem.bytesToValue(Entry, self.image[off..][0..@sizeOf(Entry)]);
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if (e.offset > self.image.len or e.len > self.image.len - e.offset) return null;
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// The name is stored in the entry's fixed field; return a stable slice
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// into the image (not the value copy) up to the NUL terminator.
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const name_field = self.image[off .. off + 32];
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const nlen = std.mem.indexOfScalar(u8, name_field, 0) orelse name_field.len;
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return .{
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.name = name_field[0..nlen],
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.blob = self.image[@intCast(e.offset)..][0..@intCast(e.len)],
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};
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}
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};
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