lib_rv32_mcu/
register_file.rs

1use log::info;
2use serde::{Deserialize, Serialize};
3
4pub use lib_rv32_isa::traits::RegisterFile as RegisterFileTrait;
5use lib_rv32_isa::{common::constants::*, RiscvError};
6
7/// Heap allocated implementation of a register file.
8#[derive(Default, Clone, Serialize, Deserialize)]
9pub struct RegisterFile {
10    registers: Vec<u32>,
11}
12
13impl RegisterFile {
14    pub fn new() -> Self {
15        RegisterFile {
16            registers: vec![0; 31],
17        }
18    }
19}
20
21impl RegisterFileTrait for RegisterFile {
22    fn write(&mut self, num: u8, data: u32) -> Result<(), RiscvError> {
23        if num > 31 {
24            return Err(RiscvError::RegisterOutOfRangeError(num));
25        } else if num >= 1 {
26            self.registers[num as usize - 1] = data;
27        }
28
29        info!(
30            "{} <- 0x{:x} ({})",
31            REG_NAMES[num as usize], data, data as i32
32        );
33
34        Ok(())
35    }
36
37    fn read(&self, num: u8) -> Result<u32, RiscvError> {
38        if num == 0 {
39            Ok(0)
40        } else if num > 31 {
41            Err(RiscvError::RegisterOutOfRangeError(num))
42        } else {
43            Ok(self.registers[num as usize - 1])
44        }
45    }
46}
47
48#[cfg(test)]
49mod tests {
50    use super::*;
51
52    #[test]
53    fn test_zero() {
54        let mut rf = RegisterFile::new();
55        rf.write(0, 17).unwrap();
56        assert_eq!(0, rf.read(0).unwrap());
57    }
58
59    #[test]
60    fn test_read_write() {
61        let mut rf = RegisterFile::new();
62        for i in 0..128 {
63            let d = i << 16;
64            for n in 0..32 {
65                rf.write(n, d).unwrap();
66                assert_eq!(if n == 0 { 0 } else { d }, rf.read(n).unwrap());
67            }
68        }
69    }
70
71    #[test]
72    fn test_out_of_range() {
73        assert_eq!(
74            Err(RiscvError::RegisterOutOfRangeError(32)),
75            RegisterFile::new().read(32)
76        )
77    }
78}
lib_rv32_mcu/register_file.rs

lib_rv32_mcu/
register_file.rs
