add s3 h2 support for USB_RAM_BLOCK

src/esploader.ts

@@ -1,6 +1,11 @@
 import { ESPError } from "./types/error.js";
 import { Data, deflate, Inflate } from "pako";
-import { Transport, SerialOptions } from "./webserial.js";
+import {
+  Transport,
+  SerialOptions,
+  ESPRESSIF_VID as ESPRESSIF_USB_VID,
+  USB_JTAG_SERIAL_PID as ESPRESSIF_USB_JTAG_SERIAL_PID,
+} from "./webserial.js";
 import { ROM } from "./targets/rom.js";
 import { ClassicReset, CustomReset, HardReset, ResetConstructors, ResetStrategy, UsbJtagSerialReset } from "./reset.js";
 import { getStubJsonByChipName } from "./stubFlasher.js";
@@ -159,7 +164,8 @@
     0x3a: "64MB",
   };
 
-  USB_JTAG_SERIAL_PID = 0x1001;
+  ESPRESSIF_VID = ESPRESSIF_USB_VID;
+  USB_JTAG_SERIAL_PID = ESPRESSIF_USB_JTAG_SERIAL_PID;
 
   chip!: ROM;
   IS_STUB: boolean;
@@ -585,6 +591,71 @@
     return lastError;
   }
 
+  /**
+   * True if the host sees this port as Espressif USB Serial/JTAG (VID/PID match).
+   * Falls back to the chip UARTDEV_BUF_NO helper when Web Serial omits IDs
+   * or the USB product ID was customized.
+   */
+  async usesUsbJtagSerial(): Promise<boolean> {
+    const vid = this.transport.getVid();
+    const pid = this.transport.getPid();
+    if (vid === this.ESPRESSIF_VID && pid === this.USB_JTAG_SERIAL_PID) {
+      return true;
+    }
+    if (vid === this.ESPRESSIF_VID && pid === this.chip.IMAGE_CHIP_ID) {
+      return false;
+    }
+    if (vid !== undefined && vid !== this.ESPRESSIF_VID) {
+      return false;
+    }
+    if (typeof this.chip.usesUsbJtagSerial === "function") {
+      return await this.chip.usesUsbJtagSerial(this);
+    }
+    return false;
+  }
+
+  /**
+   * True if the host sees this port as Espressif USB-OTG (VID/PID match).
+   * Falls back to the chip UARTDEV_BUF_NO helper when Web Serial omits IDs
+   * or the USB product ID was customized.
+   */
+  async usesUsbOtg(): Promise<boolean> {
+    const vid = this.transport.getVid();
+    const pid = this.transport.getPid();
+    if (vid === this.ESPRESSIF_VID && this.chip.IMAGE_CHIP_ID != null && pid === this.chip.IMAGE_CHIP_ID) {
+      return true;
+    }
+    if (vid === this.ESPRESSIF_VID && pid === this.USB_JTAG_SERIAL_PID) {
+      return false;
+    }
+    if (vid !== undefined && vid !== this.ESPRESSIF_VID) {
+      return false;
+    }
+    if (typeof this.chip.usesUsbOtg === "function") {
+      return await this.chip.usesUsbOtg(this);
+    }
+    if (typeof this.chip.usingUsbOtg === "function") {
+      return await this.chip.usingUsbOtg(this);
+    }
+    return false;
+  }
+
+  /**
+   * Cap FLASH_WRITE_SIZE to USB_RAM_BLOCK when the stub is talking over
+   * USB-OTG. Matches esptool.py's stub USB buffer limit; USB-Serial/JTAG
+   * and USB-UART bridges keep the 16 KB default.
+   */
+  private async applyUsbFlashWriteSize() {
+    const usbRamBlock = this.chip.USB_RAM_BLOCK;
+    if (!usbRamBlock) {
+      return;
+    }
+    if (await this.usesUsbOtg()) {
+      this.FLASH_WRITE_SIZE = usbRamBlock;
+      this.debug(`Using USB_RAM_BLOCK (0x${usbRamBlock.toString(16)}) for FLASH_WRITE_SIZE (USB-OTG)`);
+    }
+  }
+
   /**
    * Constructs a sequence of reset strategies based on the OS,
    * used ESP chip, external settings, and environment variables.
@@ -1272,6 +1343,8 @@
   async runStub(): Promise<ROM> {
     if (this.syncStubDetected) {
       this.info("Stub is already running. No upload is necessary.");
+      this.IS_STUB = true;
+      await this.applyUsbFlashWriteSize();
       return this.chip;
     }
 
@@ -1311,6 +1384,7 @@
 
     this.info("Stub running...");
     this.IS_STUB = true;
+    await this.applyUsbFlashWriteSize();
     return this.chip;
   }
 

src/index.ts

@@ -9,7 +9,7 @@ export {
   ResetStrategy,
 } from "./reset.js";
 export { ROM } from "./targets/rom.js";
-export { Transport, SerialOptions } from "./webserial.js";
+export { Transport, SerialOptions, ESPRESSIF_VID, USB_JTAG_SERIAL_PID } from "./webserial.js";
 export { decodeBase64Data, getStubJsonByChipName, Stub } from "./stubFlasher.js";
 export { LoaderOptions } from "./types/loaderOptions.js";
 export { FlashOptions } from "./types/flashOptions.js";

src/targets/esp32h2.ts

@@ -94,6 +94,11 @@ export class ESP32H2ROM extends ESP32C6ROM {
     }
   }
 
+  public async usesUsbJtagSerial(loader: ESPLoader): Promise<boolean> {
+    const bufNo = (await loader.readReg(this.UARTDEV_BUF_NO)) & 0xff;
+    return bufNo === this.UARTDEV_BUF_NO_USB;
+  }
+
   public async readMac(loader: ESPLoader) {
     let mac0 = await loader.readReg(this.MAC_EFUSE_REG);
     mac0 = mac0 >>> 0;

src/targets/esp32s3.ts

@@ -207,6 +207,11 @@ export class ESP32S3ROM extends ESP32ROM {
     }
   }
 
+  public async usesUsbJtagSerial(loader: ESPLoader): Promise<boolean> {
+    const bufNo = (await loader.readReg(this.UARTDEV_BUF_NO)) & 0xff;
+    return bufNo === this.UARTDEV_BUF_NO_USB;
+  }
+
   public async readMac(loader: ESPLoader) {
     let mac0 = await loader.readReg(this.MAC_EFUSE_REG);
     mac0 = mac0 >>> 0;

src/targets/rom.ts

@@ -67,6 +67,21 @@ export abstract class ROM {
    */
   postConnect?(loader: ESPLoader): Promise<void>;
 
+  /**
+   * True if the ROM is talking over USB-OTG (UARTDEV_BUF_NO fallback).
+   */
+  usesUsbOtg?(loader: ESPLoader): Promise<boolean>;
+
+  /**
+   * True if the ROM is talking over USB-OTG (ESP32-S2 naming).
+   */
+  usingUsbOtg?(loader: ESPLoader): Promise<boolean>;
+
+  /**
+   * True if the ROM is talking over USB-Serial/JTAG (UARTDEV_BUF_NO fallback).
+   */
+  usesUsbJtagSerial?(loader: ESPLoader): Promise<boolean>;
+
   /**
    * Get the chip erase size.
    * @param {number} offset - Offset to start erase.
@@ -101,7 +116,8 @@ export abstract class ROM {
   // abstract EFUSE_RD_REG_BASE: number; //esp32
 
   abstract FLASH_WRITE_SIZE: number;
-  // abstract IMAGE_CHIP_ID: number; // not in esp8266
+  IMAGE_CHIP_ID?: number; // not in esp8266
+  USB_RAM_BLOCK?: number; // max SLIP payload over native USB (USB-OTG / USB-Serial/JTAG)
   abstract SPI_MOSI_DLEN_OFFS: number; // not in esp8266
   abstract SPI_MISO_DLEN_OFFS: number; // not in esp8266
   abstract SPI_REG_BASE: number;

src/webserial.ts

@@ -1,6 +1,13 @@
 /* global SerialPort, ParityType, FlowControlType */
 
 import { sleep } from "./util";
+
+/** Espressif USB vendor ID used by native USB-Serial/JTAG and USB-OTG. */
+export const ESPRESSIF_VID = 0x303a;
+
+/** Default USB product ID for Espressif USB-Serial/JTAG. */
+export const USB_JTAG_SERIAL_PID = 0x1001;
+
 /**
  * Options for device serialPort.
  * @interface SerialOptions
@@ -98,6 +105,14 @@ class Transport {
       : "";
   }
 
+  /**
+   * Request the serial device vendor id from SerialPortInfo.
+   * @returns {number | undefined} Return the vendor ID.
+   */
+  getVid(): number | undefined {
+    return this.device.getInfo().usbVendorId;
+  }
+
   /**
    * Request the serial device product id from SerialPortInfo.
    * @returns {number | undefined} Return the product ID.