`mp.checksum` — 14 functions

Byte inputs are 1-based byte tables.

Function	Returns	Description
`list_crc_presets()`	table	Array of `{name, width, poly, init, reflect_in, reflect_out, xor_out}`
`crc(preset, bytes)`	table	`{value, hex, width, preset}` or `{error}`
`crc_custom(params, bytes)`	table	Custom CRC; `params = {name?, width, poly, init, reflect_in, reflect_out, xor_out}`
`crc_region(preset, r, start?, len?)`	table	CRC over a memory region (or sub-range)
`sum8(bytes)`	int	8-bit sum
`sum16(bytes)`	int	16-bit sum
`sum16_inv(bytes)`	int	Inverted 16-bit sum (two's complement)
`sum_rl78(bytes)`	int	Renesas RL78 / NEC 78K block checksum
`fletcher16(bytes)`	int	Fletcher-16
`fletcher32(bytes)`	number	Fletcher-32 (double due to range)
`adler32(bytes)`	number	Adler-32 (double)
`lrc(bytes)`	int	Longitudinal redundancy check
`bcc(bytes)`	int	Block check character (XOR reduction)
`list_builtins()`	table	Array of `{name, width}` for all non-CRC builtins

Multi-return convention for `crc()`

crc() returns three values: (value, hex_string, info_table). Pick what you need — a bare assignment grabs just the value (number).

local v = mp.checksum.crc("CRC-32", data)            -- 0xCBF43926 as number
local v, hex = mp.checksum.crc("CRC-32", data)       -- "0xCBF43926"
local v, hex, info = mp.checksum.crc("CRC-32", data) -- info.{width, preset, error}

local v, hex = mp.checksum.crc_region("CRC-32", "Flash")          -- whole region
local v, hex = mp.checksum.crc_region("CRC-32", "Flash", 0, 256)  -- slice

mp.checksum.sum8(data)                  -- simple sum, returns int
mp.checksum.fletcher16(data)
mp.checksum.adler32(data)
mp.checksum.list_crc_presets()           -- all available CRC algorithms

For Lua-based checksum scripts that drive the status bar, see Checksum scripts.

Multi-return convention for crc()​

Multi-return convention for `crc()`