crc32c(9)

🎀 crc32c — your fave little checksum bestie 💅

okay so we're in the kernel API manual, this is crc32c(9), and she is literally the moment. let's get into it ✨

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✨ SYNOPSIS ✨

u32 crc32c (u32 crc , const void *p , size_t len );

that's it. three lil args and you get a u32 back. iconic. 🫶

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🌸 ARGUMENTS 🌸

• crc — the initial CRC value, bestie. you got three moods here: ~0 (this is the recommended one, no cap), or 0 if you're starting a brand new CRC computation, or — plot twist — the previous CRC value if you're computing incrementally. incremental girlies rise 💖
• p — pointer to the data buffer. just... the data. the stuff. 🎀
• len — length of data in bytes. yes we count them. all of them. 🔥

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🦋 DESCRIPTION 🦋

so this implements CRC-32C, aka the Castagnoli CRC, and honestly? it's the recommended CRC variant to use in any new applications that want a 32-bit CRC. she's the main character of 32-bit CRCs, fr fr. 👑

here's the deets, in bullet form because we're organized and also cute:

• Polynomial: x^32 + x^28 + x^27 + x^26 + x^25 + x^23 + x^22 + x^20 + x^19 + x^18 + x^14 + x^13 + x^11 + x^10 + x^9 + x^8 + x^6 + x^0
• Bit order: Least-significant-bit-first (lsb girlies, we been knew 🌈)
• Polynomial in integer form: 0x82f63b78

⚠️ okay important one: this does not invert the CRC at the beginning or end. the caller is expected to do that if it needs to. and inverting at both ends is recommended — so like, do it. be that girl. 💅

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💜 CONTEXT 💜

Any context. any vibe. she's flexible like that. ✨

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⭐ RETURN ⭐

The new CRC value. that's the whole thing. that's what you get. 🎁

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🧚 SEE ALSO 🧚

Kernel file ./include/linux/crc32.h — plus her two siblings, crc32_le(9) and crc32_be(9). family content fr 💕

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okay that's the whole page and yes it ate 💅 this little gem lives in ./include/linux and is dated October 2026, tagging along with crc32c(9) — go forth and checksum, bestie, mwah 🍓💖✨