添加自定义的crc库(支持crc64) (#423)

kernel/crates/crc/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "crc"
+version = "0.1.0"
+edition = "2021"
+
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+
+

kernel/crates/crc/src/crc64.rs

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+//! * Normal 64-bit CRC calculation.
+//!
+//! Taken from Linux Kernel 6.1.9
+//!
+//! This is a basic crc64 implementation following ECMA-182 specification,
+//! which can be found from,
+//! https://www.ecma-international.org/publications/standards/Ecma-182.htm
+//!
+//! Dr. Ross N. Williams has a great document to introduce the idea of CRC
+//! algorithm, here the CRC64 code is also inspired by the table-driven
+//! algorithm and detail example from this paper. This paper can be found
+//! from,
+//! http://www.ross.net/crc/download/crc_v3.txt
+//!
+//! crc64table[256] is the lookup table of a table-driven 64-bit CRC
+//! calculation, which is generated by gen_crc64table.c in kernel build
+//! time. The polynomial of crc64 arithmetic is from ECMA-182 specification
+//! as well, which is defined as,
+//!
+//! x^64 + x^62 + x^57 + x^55 + x^54 + x^53 + x^52 + x^47 + x^46 + x^45 +
+//! x^40 + x^39 + x^38 + x^37 + x^35 + x^33 + x^32 + x^31 + x^29 + x^27 +
+//! x^24 + x^23 + x^22 + x^21 + x^19 + x^17 + x^13 + x^12 + x^10 + x^9 +
+//! x^7 + x^4 + x + 1
+//!
+//! crc64rocksoft[256] table is from the Rocksoft specification polynomial
+//! defined as,
+//!
+//! x^64 + x^63 + x^61 + x^59 + x^58 + x^56 + x^55 + x^52 + x^49 + x^48 + x^47 +
+//! x^46 + x^44 + x^41 + x^37 + x^36 + x^34 + x^32 + x^31 + x^28 + x^26 + x^23 +
+//! x^22 + x^19 + x^16 + x^13 + x^12 + x^10 + x^9 + x^6 + x^4 + x^3 + 1
+
+use crate::tables::crc64::{CRC64_ROCKSOFT_TABLE, CRC64_TABLE};
+
+/// crc64_be - Calculate bitwise big-endian ECMA-182 CRC64
+///
+/// ## 参数
+///
+/// - `crc`: seed value for computation. 0 or (u64)~0 for a new CRC calculation,
+///             or the previous crc64 value if computing incrementally.
+/// - `buf`: pointer to buffer over which CRC64 is run
+pub fn crc64_be(mut crc: u64, buf: &[u8]) -> u64 {
+    for &byte in buf {
+        let t = ((crc >> 56) ^ (byte as u64)) & 0xff;
+        crc = CRC64_TABLE[t as usize] ^ (crc << 8);
+    }
+    crc
+}
+
+///
+/// crc64_rocksoft_generic - Calculate bitwise Rocksoft CRC64
+///
+/// ## 参数
+///
+/// - `crc`: seed value for computation. 0 for a new CRC calculation, or the
+///            previous crc64 value if computing incrementally.
+/// - `buf`: pointer to buffer over which CRC64 is run
+pub fn crc64_rocksoft_generic(mut crc: u64, buf: &[u8]) -> u64 {
+    crc = !crc;
+
+    for &byte in buf {
+        crc = (crc >> 8) ^ CRC64_ROCKSOFT_TABLE[(((crc & 0xff) as u8) ^ (byte)) as usize];
+    }
+
+    return !crc;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn crc64_be_single() {
+        let mut buf = [0u8; 1];
+        buf[0] = 0xaa;
+        let crc = crc64_be(0, &buf);
+        assert_eq!(crc, 0x2d071b6213a0cb8b);
+    }
+
+    #[test]
+    fn crc64_be_multibytes() {
+        let buf = b"0123456789";
+        let crc = crc64_be(0, buf);
+        assert_eq!(crc, 0x2a71ab4164c3bbe8);
+    }
+}

kernel/crates/crc/src/lib.rs

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+#![cfg_attr(not(test), no_std)]
+
+#[cfg(test)]
+extern crate std;
+
+pub mod crc64;
+pub mod tables;
+
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_works() {
+        let result = add(2, 2);
+        assert_eq!(result, 4);
+    }
+}