Yes, you look to be right that the Samsung-designed Mongoose core in the Exynos SoC had 128-bytes cache line size, while ARM designed their generic Big cores to

Yes, you look to be right that the Samsung-designed Mongoose core in the Exynos SoC had 128-bytes cache line size, while ARM designed their generic Big cores to also use 64-bytes like their Little cores. Still though, seems like ARM did not provide guidance that these specs must match between Big & Little cores, and Samsung also didn't catch this either.