Fix sparse image splitting corrupting partitions on flash (bcaa6e3b) · Commits · e / devices / eOS Installer

app/public/resources/two.json

+6 −3

Original line number	Diff line number	Diff line
		@@ -4,7 +4,10 @@
		{
		"mode": "bootloader",
		"id": "connect-bootloader",
		"command": ["connect bootloader", "flashing unlock unlocked"],
		"command": [
		"connect bootloader",
		"flashing unlock unlocked"
		],
		"needUserGesture": true
		},
		{
		@@ -67,7 +70,7 @@
		],
		"folder": [
		{
		"path": "https://images.ecloud.global/official/two/IMG-e-latest-t-official-two.zip",
		"path": "https://images.ecloud.global/official/two/IMG-e-3.0.4-t-20250709507786-official-two.zip",
		"name": "Murena Two installer",
		"unzip": true
		}

app/src/controller.manager.js

+1 −1

Original line number	Diff line number	Diff line
		@@ -188,7 +188,7 @@ export class Controller {
		case Command.CMD_TYPE.erase:
		return this.deviceManager.erase(cmd.partition);
		case Command.CMD_TYPE.flash: {
		const FLASH_COOLDOWN_MS = 5000; // Pause after flash to let device stabilize
		const FLASH_COOLDOWN_MS = 1000; // Pause after flash to let device stabilize
		const result = await this.deviceManager.flash(
		cmd.file,
		cmd.partition,

app/src/lib/fastboot/sparse-image.ts

+52 −7

Original line number	Diff line number	Diff line
		@@ -131,7 +131,15 @@ function buildSparseHeader(
		*
		* This is needed when the device's max-download-size is smaller than the
		* sparse image. Each sub-image is a valid sparse image that can be downloaded
		* and flashed independently (the device will write each to the correct offsets).
		* and flashed independently.
		*
		* Each sub-image after the first includes a DONT_CARE chunk at the start to
		* skip the blocks already written by previous sub-images, so the device
		* writes each sub-image's data at the correct partition offset.
		*
		* Each sub-image's header totalBlocks = blocksOffset + dataBlocks, so the
		* chunk block sum matches the header (required by MediaTek LK and other
		* bootloaders that validate this).
		*/
		export async function splitSparseImage(
		blob: Blob,
		@@ -171,11 +179,13 @@ export async function splitSparseImage(
		return [blob];
		}

		// Group chunks into sub-images that fit within maxSize
		// Group chunks into sub-images that fit within maxSize.
		// Each sub-image after the first reserves space for a DONT_CARE prefix chunk.
		const subImages: Blob[] = [];
		let currentChunks: ChunkEntry[] = [];
		let currentSize = SPARSE_HEADER_SIZE;
		let currentBlocks = 0;
		let blocksWrittenSoFar = 0;

		for (const chunk of chunks) {
		const dataSize = chunkDataSize(chunk.header, header.blockSize);
		@@ -187,10 +197,12 @@ export async function splitSparseImage(
		currentSize + chunkTotalSize > maxSize
		) {
		subImages.push(
		buildSubImage(blob, header.blockSize, currentBlocks, currentChunks),
		buildSubImage(blob, header.blockSize, header.totalBlocks, currentChunks, blocksWrittenSoFar),
		);
		blocksWrittenSoFar += currentBlocks;
		currentChunks = [];
		currentSize = SPARSE_HEADER_SIZE;
		// Reserve space for the DONT_CARE prefix chunk in subsequent sub-images
		currentSize = SPARSE_HEADER_SIZE + SPARSE_CHUNK_HEADER_SIZE;
		currentBlocks = 0;
		}

		@@ -202,7 +214,7 @@ export async function splitSparseImage(
		// Finalize the last sub-image
		if (currentChunks.length > 0) {
		subImages.push(
		buildSubImage(blob, header.blockSize, currentBlocks, currentChunks),
		buildSubImage(blob, header.blockSize, header.totalBlocks, currentChunks, blocksWrittenSoFar),
		);
		}

		@@ -211,19 +223,38 @@ export async function splitSparseImage(

		/**
		* Build a sub-image Blob from a subset of chunks.
		*
		* @param originalTotalBlocks The ORIGINAL image's total block count.
		* @param blocksOffset Blocks already written by previous sub-images.
		* A DONT_CARE chunk is prepended to skip these blocks.
		*/
		function buildSubImage(
		originalBlob: Blob,
		blockSize: number,
		totalBlocks: number,
		originalTotalBlocks: number,
		chunks: Array<{
		header: SparseChunkHeader;
		offset: number;
		blocks: number;
		}>,
		blocksOffset: number,
		): Blob {
		const newHeader = buildSparseHeader(blockSize, totalBlocks, chunks.length);
		const hasDontCarePrefix = blocksOffset > 0;
		const numChunks = chunks.length + (hasDontCarePrefix ? 1 : 0);

		// totalBlocks for this sub-image = offset blocks + data blocks.
		// The bootloader validates that chunk blocks sum to totalBlocks.
		const dataBlocks = chunks.reduce((sum, c) => sum + c.blocks, 0);
		const subImageTotalBlocks = blocksOffset + dataBlocks;

		const newHeader = buildSparseHeader(blockSize, subImageTotalBlocks, numChunks);
		const parts: BlobPart[] = [newHeader as BlobPart];

		// Prepend a DONT_CARE chunk to skip blocks written by previous sub-images
		if (hasDontCarePrefix) {
		parts.push(buildDontCareChunk(blocksOffset) as BlobPart);
		}

		for (const chunk of chunks) {
		const dataSize = chunkDataSize(chunk.header, blockSize);
		const chunkTotalSize = SPARSE_CHUNK_HEADER_SIZE + dataSize;
		@@ -233,3 +264,17 @@ function buildSubImage(

		return new Blob(parts);
		}

		/**
		* Build a 12-byte DONT_CARE chunk header.
		* Used to skip blocks already written by previous sub-images.
		*/
		function buildDontCareChunk(chunkBlocks: number): Uint8Array {
		const buf = new ArrayBuffer(SPARSE_CHUNK_HEADER_SIZE);
		const view = new DataView(buf);
		view.setUint16(0, SparseChunkType.DontCare, true);
		view.setUint16(2, 0, true); // reserved
		view.setUint32(4, chunkBlocks, true);
		view.setUint32(8, SPARSE_CHUNK_HEADER_SIZE, true); // total size = header only
		return new Uint8Array(buf);
		}