holy shit i am a god

Author: tombl

drivers/tty/tty_io.c

@@ -1927,7 +1927,7 @@ static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp,
 #endif
 	case MKDEV(TTYAUX_MAJOR, 1): {
 		struct tty_driver *console_driver = console_device(index);
-
+		pr_info("got console %p\n", console_driver);
 		if (console_driver) {
 			driver = tty_driver_kref_get(console_driver);
 			if (driver && filp) {
@@ -2042,8 +2042,6 @@ static struct tty_struct *tty_open_by_driver(dev_t device,
 	int index = -1;
 	int retval;
 
-	pr_info("tty_open_by_driver of %i %s\n", device, filp->f_path.dentry->d_iname);
-
 	mutex_lock(&tty_mutex);
 	driver = tty_lookup_driver(device, filp, &index);
 	if (IS_ERR(driver)) {

kernel/printk/printk.c

@@ -3006,6 +3006,7 @@ struct tty_driver *console_device(int *index)
 
 	console_lock();
 	for_each_console(c) {
+		pr_info("console %s[%i] -> %p", c->name, c->index, c->device);
 		if (!c->device)
 			continue;
 		driver = c->device(c, index);

tools/wasm/public/index.html

@@ -118,7 +118,12 @@
       });
     </script>
     <script type="module">
-      import { Machine } from "./dist/index.js";
+      import {
+        BlockDevice,
+        ConsoleDevice,
+        EntropyDevice,
+        Machine,
+      } from "./dist/index.js";
 
       const term = new Terminal({
         convertEol: true,
@@ -146,19 +151,36 @@
       document.querySelector("input[name=cmdline]").value = cmdline;
       document.querySelector("input[name=memory]").value = memory;
 
+      const stdin = new ReadableStream({
+        start(controller) {
+          term.onData((data) => {
+            controller.enqueue(data);
+          });
+        },
+      });
+
+      const stdout = new WritableStream({
+        write(chunk) {
+          term.write(chunk);
+        },
+      });
+      const stdout2 = new WritableStream({
+        write(chunk) {
+          term.write(chunk);
+        },
+      });
+
       const machine = new Machine({
         cmdline: cmdline.replace(/\+/g, " "),
         memoryMib: memory,
+        devices: [
+          new ConsoleDevice(stdin, stdout),
+          new EntropyDevice(),
+          new BlockDevice(new Uint8Array(8 * 1024 * 1024)),
+        ],
       });
 
-      machine.bootConsole.pipeTo(
-        new WritableStream({
-          write(chunk) {
-            term.write(chunk);
-            // return new Promise((r) => term.write(chunk, r));
-          },
-        })
-      );
+      machine.bootConsole.pipeTo(stdout2);
 
       machine.on("halt", () => {
         term.write("halting...");

tools/wasm/run.js

@@ -1,5 +1,10 @@
 #!/usr/bin/env -S deno run --allow-read
-import { Machine } from "./dist/index.js";
+import {
+  BlockDevice,
+  ConsoleDevice,
+  EntropyDevice,
+  Machine,
+} from "./dist/index.js";
 import { parseArgs } from "jsr:@std/cli@1/parse-args";
 import { assert } from "./src/util.ts";
 
@@ -33,9 +38,14 @@ const machine = new Machine({
   cmdline: args.cmdline,
   memoryMib: args.memory,
   cpus: args.cpus,
+  devices: [
+    new ConsoleDevice(Deno.stdin.readable, Deno.stdout.writable),
+    new EntropyDevice(),
+    new BlockDevice(new Uint8Array(8 * 1024 * 1024)),
+  ],
 });
 
-machine.bootConsole.pipeTo(Deno.stdout.writable);
+machine.bootConsole.pipeTo(Deno.stderr.writable, { preventClose: true });
 
 machine.on("halt", () => {
   console.log("halting...");

tools/wasm/src/index.ts

@@ -4,16 +4,12 @@ import vmlinuxUrl from "./build/vmlinux.wasm";
 import { type DeviceTreeNode, generate_devicetree } from "./devicetree.ts";
 import init2 from "./init2.cpio";
 import { assert, EventEmitter, get_script_path, unreachable } from "./util.ts";
-import {
-  BlockDevice,
-  ConsoleDevice,
-  EntropyDevice,
-  virtio_imports,
-  VirtioDevice,
-} from "./virtio.ts";
+import { virtio_imports, VirtioDevice } from "./virtio.ts";
 import { type Imports, type Instance, kernel_imports } from "./wasm.ts";
 import type { InitMessage, WorkerMessage } from "./worker.ts";
 
+export { BlockDevice, ConsoleDevice, EntropyDevice } from "./virtio.ts";
+
 const worker_url = get_script_path(() => import("./worker.ts"), import.meta);
 
 const vmlinux_response = fetch(new URL(vmlinuxUrl, import.meta.url));
@@ -45,21 +41,12 @@ export class Machine extends EventEmitter<{
     cmdline?: string;
     memoryMib?: number;
     cpus?: number;
+    devices: VirtioDevice[];
   }) {
     super();
     this.#boot_console = new TransformStream<Uint8Array, Uint8Array>();
     this.#boot_console_writer = this.#boot_console.writable.getWriter();
-
-    this.#devices = [
-      new EntropyDevice(),
-      new ConsoleDevice(
-        new ReadableStream({
-          pull(controller) {
-          },
-        }),
-      ),
-      // new BlockDevice(),
-    ];
+    this.#devices = options.devices;
 
     const PAGE_SIZE = 0x10000;
     const BYTES_PER_MIB = 0x100000;
@@ -118,7 +105,9 @@ export class Machine extends EventEmitter<{
     const vmlinux = await vmlinux_promise;
 
     const boot_console_write = (message: ArrayBuffer) => {
-      this.#boot_console_writer.write(new Uint8Array(message));
+      this.#boot_console_writer.write(new Uint8Array(message)).catch(() => {
+        // Ignore errors if the console is closed
+      });
     };
     const boot_console_close = () => {
       this.#boot_console_writer.close();

tools/wasm/src/init2.cpio

@@ -188,12 +188,12 @@ export abstract class VirtioDevice<Config extends object = object> {
   vqs: Virtqueue[] = [];
   enable(vq: number, queue: Virtqueue) {
     this.vqs[vq] = queue;
-    console.log("enable", vq, queue.size);
+    console.log("enable", this.constructor.name, vq, queue.size);
   }
   disable(vq: number) {
     const queue = this.vqs[vq];
     assert(queue);
-    console.log("disable", vq);
+    console.log("disable", this.constructor.name, vq);
   }
 
   abstract notify(vq: number): void;
@@ -236,12 +236,13 @@ export class BlockDevice extends VirtioDevice<BlockDeviceConfig> {
   config_bytes = new Uint8Array(BlockDeviceConfig.size);
   config = new BlockDeviceConfig(this.config_bytes);
 
-  storage = new Uint8Array(1024 * 1024);
+  #storage: Uint8Array;
 
-  constructor() {
+  constructor(storage: Uint8Array) {
     super();
+    this.#storage = storage;
     this.features |= BlockDeviceFeatures.FLUSH;
-    this.config.capacity = BigInt(this.storage.byteLength / 512);
+    this.config.capacity = BigInt(this.#storage.byteLength / 512);
   }
 
   override notify(vq: number) {
@@ -273,8 +274,8 @@ export class BlockDevice extends VirtioDevice<BlockDeviceConfig> {
           assert(data.writable, "data must be writable when IN");
           const start = Number(request.sector) * 512;
           let end = start + data.array.byteLength;
-          if (end >= this.storage.length) end = this.storage.length - 1;
-          data.array.set(this.storage.subarray(start, end));
+          if (end >= this.#storage.length) end = this.#storage.length - 1;
+          data.array.set(this.#storage.subarray(start, end));
           n = end - start;
           status.array[0] = BlockDeviceStatus.OK;
           break;
@@ -284,12 +285,6 @@ export class BlockDevice extends VirtioDevice<BlockDeviceConfig> {
           status.array[0] = BlockDeviceStatus.UNSUPP;
       }
 
-      console.log(
-        request.type,
-        request.sector,
-        status.array[0],
-      );
-
       chain.release(n);
     }
     this.trigger_interrupt("vring");
@@ -302,40 +297,61 @@ export class ConsoleDevice extends VirtioDevice<EmptyStruct> {
   config = new EmptyStruct(this.config_bytes);
 
   #input: ReadableStream<Uint8Array>;
-  constructor(input: ReadableStream<Uint8Array>) {
+  #output: WritableStreamDefaultWriter<Uint8Array>;
+  constructor(
+    input: ReadableStream<Uint8Array>,
+    output: WritableStream<Uint8Array>,
+  ) {
     super();
     this.#input = input;
+    this.#output = output.getWriter();
   }
 
   #writing: Promise<void> | null = null;
+  async #writer(queue: Virtqueue) {
+    const queueIter = queue[Symbol.iterator]();
+    for await (let chunk of this.#input) {
+      while (chunk.length > 0) {
+        const chain = queueIter.next().value;
+        if (!chain) {
+          console.warn("no more descriptors, dropping console input");
+          break;
+        }
 
-  override notify(vq: number) {
-    assert(vq === 0);
+        const [desc, trailing] = chain;
+        assert(desc && desc.writable, "receiver must be writable");
+        assert(!trailing, "too many descriptors");
 
+        const n = Math.min(chunk.length, desc.array.byteLength);
+        desc.array.set(chunk.subarray(0, n));
+        chunk = chunk.subarray(n);
+        chain.release(n);
+      }
+    }
+  }
+
+  override async notify(vq: number) {
     const queue = this.vqs[vq];
     assert(queue);
-    const queueIter = queue[Symbol.iterator]();
 
-    this.#writing ??= (async () => {
-      for await (let chunk of this.#input) {
-        while (chunk.length > 0) {
-          const chain = queueIter.next().value;
-          if (!chain) {
-            console.warn("no more descriptors, dropping console input");
-            break;
+    switch (vq) {
+      case 0:
+        this.#writing ??= this.#writer(queue);
+        break;
+      case 1:
+        for (const chain of queue) {
+          let n = 0;
+          for (const { array, writable } of chain) {
+            assert(!writable, "transmitter must be readable");
+            await this.#output.write(array);
+            n += array.byteLength;
           }
-
-          const [desc, trailing] = chain;
-          assert(desc && desc.writable, "receiver must be writable");
-          assert(!trailing, "too many descriptors");
-
-          const n = Math.min(chunk.length, desc.array.byteLength);
-          desc.array.set(chunk.subarray(0, n));
-          chunk = chunk.subarray(n);
           chain.release(n);
         }
-      }
-    })();
+        break;
+      default:
+        console.error("ConsoleDevice: unknown vq", vq);
+    }
   }
 }