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/builtins.zig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'src/builtins.zig') diff --git a/src/builtins.zig b/src/builtins.zig index 23ae18c3..2c52b5f9 100644 --- a/src/builtins.zig +++ b/src/builtins.zig @@ -42,7 +42,7 @@ pub const capabilities: runtime_config.Capabilities = .{ .scene_shaders = pardes.platform == .gui or pardes.platform == .macos, // The tty's font belongs to its emulator, and the P4 firmware's belongs to // whatever terminal is on the other end of the serial line. - .tagline_font_size = pardes.platform != .tty and pardes.platform != .p4, + .tagline_font_size = pardes.platform != .tty and pardes.platform != .esp32p4, }; /// What a builtin gets to act on. One bundle rather than five parameters @@ -922,7 +922,7 @@ pub const Lspwhy = struct { // // Three words gated by `board_memory.enabled`, which is a fact about the // TARGET (freestanding, and not wasm) rather than about `pardes.platform` — -// see the reasoning there. Today that is exactly `-Dplatform=p4`; what makes +// see the reasoning there. Today that is exactly `-Dplatform=esp32p4`; what makes // it the right predicate is that a second bare-metal port gets them without // anyone remembering to add an enum arm, and the browser never does. // Elsewhere they are absent from the command enum, the help index, the leader -- cgit v1.3