decode_rs8(9)

hey bestie 💖 okay so this is the decode_rs8(9) page from the Kernel API Manual — section 9, no cap.

🎀 NAME 🎀

decode_rs8 — Decode codeword (8bit data width). that's the whole vibe: it's the decoder for 8-bit data width. slay.

✨ SYNOPSIS ✨

here's the exact signature, character for character — don't let the line wrap gaslight you:

int decode_rs8 (struct rs_control *rsc , uint8_t *data , uint16_t *par ,
int len , uint16_t *s , int no_eras , int *eras_pos , uint16_t invmsk ,
uint16_t *corr );

🌸 ARGUMENTS 🌸

okay bestie, argument-by-argument, let's go:

• rsc — the rs control structure. main character energy.
• data — data field of a given type. yep, that's the field.
• par — received parity data field. the parity bestie.
• len — data length. how long the data is, periodt.
• s — syndrome data field, and it must be in index form. if it's NULL, the syndrome is calculated. iconic convenience.
• no_eras — number of erasures. count 'em.
• eras_pos — position of erasures. can be NULL, so no pressure.
• invmsk — invert data mask. IMPORTANT: it will be xored on data, not on parity! literally not parity, bestie — data only. 💅
• corr — buffer to store correction bitmask on eras_pos. that's its whole job.

🦋 DESCRIPTION 🦋

so here's the tea: the syndrome and parity uses a uint16_t data type to enable symbol size > 8. highkey useful. The calling code must take care of decoding of the syndrome result and the received parity before calling this code. no cap, that part is on the caller.

💜 NOTE 💜

The rs_control struct rsc contains buffers which are used for decoding, so the caller has to ensure that decoder invocations are serialized. like, one at a time, bestie — don't let them overlap. 🫶

Returns the number of corrected symbols or -EBADMSG for uncorrectable errors. The count includes errors in the parity. so yes, parity errors are in the count too — the way that detail matters. 😭

👑 SEE ALSO 👑

go read these next, iykyk:

• Kernel file ./lib/reed_solomon/reed_solomon.c
• codec_init(9)
• free_rs(9)
• init_rs_internal(9)
• init_rs_gfp(9)
• init_rs_non_canonical(9)
• encode_rs8(9)
• encode_rs16(9)
• decode_rs16(9)

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this page is brought to you by source ./lib/reed_solomon, dated October 2026, and it's the decode_rs8(9) page in the Kernel API Manual. stay slay, bestie 💅✨