Files
trve/src/instructions/rvi.rs

51 lines
1.6 KiB
Rust

use crate::{
consts::{Addr, DWord},
core::{Core, InstructionResult},
decode::Instruction,
instructions::{
OpcodeHandler,
gen_tools::insert_funct3_splitter,
opcodes::{OP_IMM, STORE},
},
mem::PageNum,
};
pub(super) fn add_instrs(list: &mut [OpcodeHandler; 32]) {
let funct3_split_op_imm = insert_funct3_splitter(&mut list[OP_IMM as usize].splitter);
funct3_split_op_imm[0b000].handler = Some(super::InstructionHandler { runner: addi }); // ADDI
let funct3_split_store = insert_funct3_splitter(&mut list[STORE as usize].splitter);
funct3_split_store[0b011].handler = Some(super::InstructionHandler { runner: sd }) // SD
}
fn addi(core: &mut Core, instr: Instruction) -> InstructionResult {
core.reg_write(
instr.rd(),
core.reg_read(instr.rs1()).wrapping_add(instr.imm_i()),
);
core.pc = core.pc.wrapping_add(4);
InstructionResult::Normal
}
fn sd(core: &mut Core, instr: Instruction) -> InstructionResult {
let addr = core.reg_read(instr.rs1()).wrapping_add(instr.imm_s());
if !addr.is_multiple_of(std::mem::size_of::<DWord>() as Addr) {
return InstructionResult::Exception(());
}
let page = (addr / 4096) as PageNum;
let offset = (addr & ((4096 / std::mem::size_of::<DWord>() as Addr) - 1)) as u16;
let value = core.reg_read(instr.rs2());
match core.mem.write_dword(page, offset, value) {
Ok(_) => {
core.pc = core.pc.wrapping_add(4);
InstructionResult::Normal
}
Err(_) => InstructionResult::Exception(()),
}
}