From 11f380f6d7222f2cad93c2cdf13701ea1f903d47 Mon Sep 17 00:00:00 2001 From: Gabriel Schneider Date: Wed, 26 Aug 2026 13:27:46 -0300 Subject: One core behind N frontends, the board's own runner moved in, and every board cap on one screen MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ## The wire is the effect stream, not a new protocol `pardes --detach` leaves a core running with no terminal; `pardes --attach` is a frontend that owns a terminal and a socket and nothing else. N frontends on one core all look at the same screen — `screen -x`, not N sessions. The codec (`src/detached/wire.zig`) carries exactly one `Event` or one `Host.VTable` call per message. That is not a coincidence and it is why there is no third vocabulary to keep in step: the core's IO seam was already a struct of function pointers with plain-data arguments, so a socket is a legal implementation of it. `nested.zig`'s socket could not be reused — it carries a builtin command line, and a command line cannot carry a frame. ARCHITECTURE-NEUTRAL on purpose, not as decoration. The frontend on the far end may be riscv32-freestanding on the ESP32-P4 while the core is x86_64 Linux, so every field is an explicit little-endian fixed width and no message is a blit of a native struct. A protocol that only works between two builds of the same compiler would have thrown away the one frontend that motivated it. ## The board comes in; its toolchain stays out `src/p4.zig` becomes `src/esp32p4.zig`, and the pardes half of `../05-zig-p4` — the vaxis-over- serial runner, the UART editor terminal, the keystroke rescue ring, the on-die test suite — moves into `src/esp32p4/`. `build.zig.zon` gains `.zig_p4 = .{ .path = "../05-zig-p4" }`, so `zig build -Dplatform=esp32p4 -Desp32p4-firmware` builds, flashes, monitors and self-tests the board from this repo's `build.zig`. The DIVISION is the point. What moved is what only pardes wants: the runner that drives a pardes core over a serial line. What stayed is everything a second project would also want — the HAL, the register/radio/oracle layers, the linker script, `_start`. `zig_p4` declares no dependencies of its own and its `build()` early-returns when it is not the root package, so this costs the package graph exactly zero packages and the editor's own builds nothing at all. ## limits.zig: nine forgettable places become one budget Nine `platform == .esp32p4` capacity tests lived in nine files. They were never nine decisions — they are ONE decision, how much memory this build may spend, taken nine times where no reader could see the total. `src/limits.zig` puts the whole budget on one screen with every cap named against what it is measured against, derived from two booleans. The payoff is testability on a machine that is not the board: the caps are ordinary comptime values, so a host build can be compiled against the board's numbers and the parking, eviction and clamping paths a 240 KiB core takes get exercised by the normal test suite instead of only over a UART. ## A bare `zig build` `zig build` with no arguments now builds the tty and GUI binaries and installs them into `~/.local/bin`, and says so once on stdout with the flag that overrides it. The old default built one binary into `zig-out` — a path nothing on a `PATH` ever looks at, which made "build it" and "use it" two different commands for no reason. --- src/dump.zig | 24 +++++++----------------- 1 file changed, 7 insertions(+), 17 deletions(-) (limited to 'src/dump.zig') diff --git a/src/dump.zig b/src/dump.zig index 37ba83c0..f8740cdb 100644 --- a/src/dump.zig +++ b/src/dump.zig @@ -1,5 +1,6 @@ const std = @import("std"); const builtin = @import("builtin"); +const limits = @import("limits.zig"); // scoped, not bare std.log: main.zig's logFn drops the unscoped .default scope // wholesale (ghostty and uucode log there too), and a corrupt dump's parse @@ -40,22 +41,11 @@ pub const magic = "pardes-dump"; pub const version: u32 = 1; pub const max_panes: usize = 16; pub const max_cols: usize = 6; -/// Bounds the only user-editable, schema-owned tag fragment. Keep this beside -/// the dump limits so readers can reject data before copying it into a pane. -/// It IS the storage bound: `Pane.tag_tail` is `[max_tag_tail]u8`, and every -/// writer (appendTag, tagInsert, restoreDumpTail, the acmefs `tag` file) -/// refuses input that does not fit rather than truncating it, so the schema -/// limit and the buffer can never disagree. -/// -/// 512 on the P4 firmware. A tag is ONE line — a pane's path plus its command -/// words — and 4 KiB of it is 4 KiB per pane out of a 384 KiB heap. A serial -/// console is 80 columns; 512 is six of those. -pub const max_tag_tail: usize = - if (@import("pardes_config").platform == .p4) 512 else 4096; /// Output arguments are typed in the same bounded one-line tag storage. Keep /// the schema limit named independently so a dump reader can validate it -/// without importing the output-pane implementation. -pub const max_origin_arg: usize = max_tag_tail; +/// without importing the output-pane implementation. The bound itself is +/// `limits.max_tag_tail` — the one place a board-shaped capacity is chosen. +pub const max_origin_arg: usize = limits.max_tag_tail; pub const Size = struct { cols: u16, @@ -157,7 +147,7 @@ pub fn validate(state: State) !void { if (!std.math.isFinite(pane.vweight) or pane.vweight <= 0) return error.BadDumpPaneWeight; if (pane.scroll > std.math.maxInt(i32)) return error.BadDumpPaneScroll; - if (pane.tag_tail) |tail| if (tail.len > max_tag_tail) + if (pane.tag_tail) |tail| if (tail.len > limits.max_tag_tail) return error.BadDumpTagTail; if (pane.file) |file| if (file.origin_arg.len > max_origin_arg) return error.BadDumpOriginArg; @@ -412,9 +402,9 @@ test "validation bounds pane restore state" { try std.testing.expectError(error.BadDumpPaneScroll, validate(state)); panes[0].scroll = 0; - var oversized_tail: [max_tag_tail + 1]u8 = @splat('x'); + var oversized_tail: [limits.max_tag_tail + 1]u8 = @splat('x'); panes[0].tag_tail = &oversized_tail; try std.testing.expectError(error.BadDumpTagTail, validate(state)); - panes[0].tag_tail = oversized_tail[0..max_tag_tail]; + panes[0].tag_tail = oversized_tail[0..limits.max_tag_tail]; try validate(state); } -- cgit v1.3