Method readPart

tools/xsbug/esptool.js:321–390

(offset, size)

		return result;
	}
	async readPart(offset, size) {
//		ROM loader is limited to sector boundaries but RAM loader supports arbitrary offsets
//		if ((offset % 4096) || (size % 4096))
//			throw new Error("must be aligned to sectors");

		const payload = new DataView(new ArrayBuffer(4 * 4));
		payload.setUint32(0, offset, 1);
		payload.setUint32(4, size, 1);
		payload.setUint32(8, 4096, 1);
		payload.setUint32(12, 1, 1);		// max-in-flight
		await this.command(Bootloader.READ_FLASH, new Uint8Array(payload.buffer));

		let initial;
		let reply = await this.getReply();
		this.parseReply(reply, Bootloader.READ_FLASH);
		const position = reply.indexOf(0xC0, 1);
		if (position < (reply.length - 1))
			initial = reply.slice(position + 1);

		let result = new Uint8Array;
		let buffered = new Uint8Array;
		let progress = new DataView(new ArrayBuffer(1 * 4));
		while (result.byteLength < size) {
			const data = initial ?? this.#serial.read();
			if (!data) {
				const readPromise = new Promise(resolve => {
					this.#readable = resolve;
				});
				await Promise.race([readPromise, new Promise(resolve => setTimeout(resolve, 100))]);
				continue;
			}

			initial = undefined;
			let t = new Uint8Array(buffered.byteLength + data.byteLength);
			t.set(buffered, 0);
			t.set(new Uint8Array(data), buffered.byteLength);
			buffered = t;

			if (0xC0 !== buffered[0])
				throw new Error("bad data received");
			const end = buffered.indexOf(0xC0, 1);
			if (end < 0)
				continue;

			const slipPacket = this.unescapeSLIP(buffered.slice(0, end + 1));
			if ((size + 2) !== slipPacket.byteLength)
				throw new Error("bad packet size");
			buffered = buffered.slice(end + 1);

			t = new Uint8Array(result.byteLength + slipPacket.byteLength - 2);
			t.set(result, 0);
			t.set(new Uint8Array(slipPacket.buffer, 1, slipPacket.byteLength - 2), result.byteLength);
			result = t;

			progress.setUint32(0, result.byteLength, 1);
			this.writeSLIP(progress.buffer, false);
		}