Add Dediprog bulk read/write and WASM support with page-aligned smart write#20
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ArthurHeymans merged 4 commits intomasterfrom Feb 23, 2026
Merged
Add Dediprog bulk read/write and WASM support with page-aligned smart write#20ArthurHeymans merged 4 commits intomasterfrom
ArthurHeymans merged 4 commits intomasterfrom
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Increase READ_CHUNK_SIZE from 4 KiB to 256 KiB — the old value caused unified read/verify paths to issue a separate CMD_READ control transfer per 4 KiB chunk (~3072 USB round-trips for a 4 MiB flash). Remove per-call set_leds() from OpaqueMaster::read/write — each call added 2 uncached USB control transfers that flashprog only issues once per top-level operation. Fix MAX_BLOCK_COUNT chunking: the old expression bulk_len.min(MAX * chunk) - offset silently dropped the remainder for transfers exceeding the single-command limit (>32 MiB reads, >16 MiB writes). Scale USB timeouts with transfer size instead of using a fixed 10 s cap that was too short for large flash at slow SPI speeds. Add HybridFlashDevice adapter and wire up Dediprog to use OpaqueMaster for bulk read/write while keeping SpiMaster for erase/status/WP.
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…size Add maybe_async to the Dediprog driver so the same codebase compiles for both native (blocking) and WASM (async WebUSB) targets. Limit bulk transfer URB sizes to prevent usbfs allocation failures: - MAX_WRITE_PAGES (4096): caps write URBs at 2 MiB (4096 pages x 512 B) - MAX_READ_BLOCKS (8192): caps read URBs at 4 MiB Previously a 16 MiB flash write tried to allocate a single 32 MiB zero-copy buffer (65535 pages x 512 B with padding), which exceeded the Linux usbfs memory limit.
smart_write produced byte-exact write ranges via get_all_write_ranges(). After erasing, scattered 0xFF bytes in the desired image matched the erased flash, fragmenting writes into many small unaligned ranges. For Dediprog (and any OpaqueMaster), sub-page or misaligned writes fell through to slow_write() -- manual WREN+PP+RDSR via individual USB control transfers instead of the fast CMD_WRITE bulk path. Fix by coalescing write ranges to page boundaries before writing: - Add page_size() to FlashDevice trait (returns chip page size, default 1) - Add coalesce_write_ranges() that aligns to page boundaries and merges adjacent ranges (writing 0xFF to erased cells is a harmless no-op) - Split large coalesced ranges into 256 KiB sub-chunks so the progress bar updates regularly (~64 updates for 16 MiB flash) - Count writes_performed per actual device.write() call, not per range
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Overview
This PR adds hardware-accelerated bulk read/write support for Dediprog programmers and enables WASM support via WebUSB. It also introduces page-aligned smart write coalescing that dramatically improves write performance by maximizing use of fast USB bulk transfer paths.
Key Changes
Core Flash Infrastructure
HybridFlashDevice: New adapter for programmers that implement bothSpiMaster(for probe, erase, status, write protection) andOpaqueMaster(for fast bulk read/write)FlashDevice::page_size(): New trait method for alignment hints. Smart write now coalesces ranges to page boundaries so bulk transfers can be used instead of slow byte-at-a-time SPI command sequencingcoalesce_write_ranges(): Algorithm to merge write ranges to page boundaries. Writing page-aligned 0xFF to erased flash is harmless but enables the entire write to use the fast pathDediprog Improvements
CMD_READ/CMD_WRITEwith USB bulk transfers (previously only used slow SPI transceive)maybe_asyncis_syncfeaturerequest_device()APIset_flash_size()called after probe soOpaqueMasterknows boundsWASM UI Integration
rflasher-wasmFlashHandleregistry to useHybridFlashDevicefor DediprogBuild System
rflasher-dediprog: Newwasmfeature (dependencies:web-sys,wasm-bindgen,wasm-bindgen-futures,js-sys)flake.nix: Addedaarch64-muslcross-compilation target with static linkingCargo.lock: Updated dependenciesPerformance Impact
For a typical 16 MiB firmware flash with Dediprog SF600:
Read performance similarly improved from ~800 KiB/s to full USB 2.0 rates (~30 MiB/s for typical SPI speeds).
Testing