[core] Support block-compressed NSZ and XCZ (#4552)

2026-10-26T16:23:18+00:00

- [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions). - [x] I have read and followed the [AI Policy](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/AI.md). - [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability. ------------------- - Add NCZBLOCK (nsz -B / .xcz) reader: each read decodes only the covered blocks and re-encrypts CTR sections, no disk output. - Allow installing solid .nsz to NAND via DecompressNCZForInstall (lazy, incremental decode with frontier, O(n) instead of O(n^2)). - Accept BKTR updates with thousands of sections (MaxSectionCount = 0x10000). - Wire .nsz/.xcz into loader, registered cache, scanner, and NAND install (content_manager.h), and reject solid NCZ from the game list. - Bump the pinned zstd to 33618c8 in cpmfile.json, which includes the upstream AArch64 revert ([33618c89](https://github.com/facebook/zstd/commit/33618c89e511637f8a6ef955b3501766d71feb53)) for a ZSTD_decodeSequence branch optimization that could corrupt data on ARM64; without it, solid NCZ decoding on Android fails with "Data corruption detected". NCZ format and CTR counter semantics follow the reference nsz tool and its Rust port: - https://github.com/nicoboss/nsz (Decompressor.py, BlockDecompressorReader.py) - https://docs.rs/nsz-rs/0.3.0/src/nsz_rs/decompress.rs.html The last-block edge case (decompressed size is an exact multiple of block size) is handled as described in https://github.com/nicoboss/nsz/issues/210 Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4552 Reviewed-by: CamilleLaVey Reviewed-by: Shinmegumi

eglantine-cirakg/src/core/crypto/ncz_decompressor.cpp, branch nx2

[core] Support block-compressed NSZ and XCZ (#4552)