csum8(9)

💫 csum8(9) — the kernel API manual, bestie edition 💫

okay so real talk: this is a page from the Kernel API Manual, and today's main character is csum8(9). yes babes, we're doing checksums. it's giving "small function, big responsibilities" and honestly? iconic. ✨

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🌸 NAME 🌸

csum8 — Calculate 8-bit checksum on data

like, that's literally the whole job. one byte of checksum, no drama, no cap. 💅

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🎀 SYNOPSIS 🎀

u8 csum8 (const u8 *data , size_t size , u8 base );

look at her. three params, one u8 return, zero notes. she's lowkey perfect. 🦋

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✨ ARGUMENTS ✨

• data — the bytes you want the 8-bit checksum of. yes, these bytes. the ones you picked. 🫶
• size — number of bytes. gotta tell her how much of data to actually look at, bestie, she's not a mind reader. 😭
• base — the starting value for the checksum. your little head start. your pre-game. your opening number. 🌈

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👑 SEE ALSO 👑

okay this is the part where the manpage just starts name-dropping the whole friend group and honestly? respect. 💀 every one of these:

• Kernel file ./drivers/greybus/gb-beagleplay.c
• struct gb_beagleplay(9)
• struct hdlc_payload(9)
• struct hdlc_greybus_frame(9)
• enum cc1352_bootloader_cmd(9)
• enum cc1352_bootloader_status(9)
• struct cc1352_bootloader_packet(9)
• struct cc1352_bootloader_download_cmd_data(9)
• struct cc1352_bootloader_crc32_cmd_data(9)
• hdlc_write(9)
• hdlc_append(9)
• hdlc_encoded_length(9)
• hdlc_tx_frames(9)
• cc1352_bootloader_pkt_rx(9)
• gb_message_send(9)
• cc1352_bootloader_empty_pkt(9)

ngl that's a lot of references for one tiny checksum function, but she clearly runs with a crowd. iykyk. 🔥

fr fr though — if you're poking at csum8 you're probably already deep in ./drivers/greybus territory, so maybe go say hi to the rest of the squad up there. 🧚

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and that's the whole page, bestie, nothing skipped, nothing hidden. 🍓 this lil cutie lives in ./drivers/greybus and this snapshot is dated October 2026 — csum8(9), kernel API manual, periodt. 💖🦋🎀