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/*
* Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
*
* This file is part of nios2sim-ng.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <stdio.h>
#include "nios2sim-ng.h"
#include "instruction.h"
#include "nios2.h"
static inline uint32_t get_opcode(uint32_t code)
{
I_TYPE(instr, code);
return instr->op;
}
static inline uint32_t get_opxcode(uint32_t code)
{
R_TYPE(instr, code);
return instr->opx.opx11;
}
static int unsupported(struct nios2 *cpu, uint32_t code)
{
info("Unsupported instructtion %08x @ PC %08x\n", code, cpu->pc);
return PC_INC_NORMAL;
}
/*
* J-Type instructions
*/
static int call(struct nios2 *cpu, uint32_t code)
{
J_TYPE(instr, code);
return PC_INC_BY_INSTR;
}
static int jmpi(struct nios2 *cpu, uint32_t code)
{
J_TYPE(instr, code);
return PC_INC_BY_INSTR;
}
/*
* I-Type instructions
*/
static int ldbu(struct nios2 *cpu, uint32_t code)
{
I_TYPE(instr, code);
return PC_INC_NORMAL;
}
static int addi(struct nios2 *cpu, uint32_t code)
{
I_TYPE(instr, code);
uint32_t *gp_regs = cpu->gp_regs;
/* rB <- rA + IMM16 */
gp_regs[instr->b] = gp_regs[instr->a] + (int16_t) (instr->imm16);
return PC_INC_NORMAL;
}
static int ldhu(struct nios2 *cpu, uint32_t code)
{
I_TYPE(instr, code);
return PC_INC_NORMAL;
}
static int andi(struct nios2 *cpu, uint32_t code)
{
I_TYPE(instr, code);
uint32_t *gp_regs = cpu->gp_regs;
/* rB <- rA & IMM16 */
gp_regs[instr->b] = gp_regs[instr->a] & (int32_t) (instr->imm16 & BIT_MASK(16));
return PC_INC_NORMAL;
}
static int ori(struct nios2 *cpu, uint32_t code)
{
I_TYPE(instr, code);
uint32_t *gp_regs = cpu->gp_regs;
/* rB <- rA | IMM16 */
gp_regs[instr->b] = gp_regs[instr->a] | (int32_t) (instr->imm16 & BIT_MASK(16));
return PC_INC_NORMAL;
}
static int xori(struct nios2 *cpu, uint32_t code)
{
I_TYPE(instr, code);
uint32_t *gp_regs = cpu->gp_regs;
/* rB <- rA ^ IMM16 */
gp_regs[instr->b] = gp_regs[instr->a] ^ (int32_t) (instr->imm16 & BIT_MASK(16));
return PC_INC_NORMAL;
}
/*
* R-Type instructions
*/
static int and(struct nios2 *cpu, uint32_t code)
{
R_TYPE(instr, code);
uint32_t *gp_regs = cpu->gp_regs;
/* rC <- rA & rB */
gp_regs[instr->c] = gp_regs[instr->a] & gp_regs[instr->b];
return PC_INC_NORMAL;
}
static int or(struct nios2 *cpu, uint32_t code)
{
R_TYPE(instr, code);
uint32_t *gp_regs = cpu->gp_regs;
/* rC <- rA | rB */
gp_regs[instr->c] = gp_regs[instr->a] | gp_regs[instr->b];
return PC_INC_NORMAL;
}
static int add(struct nios2 *cpu, uint32_t code)
{
R_TYPE(instr, code);
uint32_t *gp_regs = cpu->gp_regs;
/* rC <- rA + rB */
gp_regs[instr->c] = gp_regs[instr->a] + gp_regs[instr->b];
return PC_INC_NORMAL;
}
static int sync(struct nios2 *cpu, uint32_t code)
{
/* Nothing to do here */
return PC_INC_NORMAL;
}
static int sub(struct nios2 *cpu, uint32_t code)
{
R_TYPE(instr, code);
uint32_t *gp_regs = cpu->gp_regs;
/* rC <- rA - rB */
gp_regs[instr->c] = gp_regs[instr->a] - gp_regs[instr->b];
return PC_INC_NORMAL;
}
static instruction_handler r_type_instr_handlers[R_TYPE_COUNT] = {
[AND] = and,
[OR] = or,
[ADD] = add,
[BREAK] = unsupported,
[SYNC] = sync,
[SUB] = sub,
[SRAI] = unsupported,
[SRA] = unsupported,
};
static int handle_r_type_instr(struct nios2 *cpu, uint32_t code)
{
uint32_t opx;
instruction_handler handle_instr;
opx = get_opxcode(code);
if (unlikely(opx >= R_TYPE_COUNT)) {
err("Invalid OPX code %08x\n", opx);
return INSTR_ERR;
}
handle_instr = r_type_instr_handlers[opx];
if (unlikely(handle_instr == NULL)) {
err("Invalid instruction %08x\n", code);
return INSTR_ERR;
}
return handle_instr(cpu, code);
}
static instruction_handler i_type_instr_handlers[I_TYPE_COUNT] = {
[CALL] = call,
[JMPI] = jmpi,
[LDBU] = ldbu,
[ADDI] = addi,
[STB] = unsupported,
[BR] = unsupported,
[LDB] = unsupported,
[CMPGEI] = unsupported,
[LDHU] = ldhu,
[ANDI] = andi,
[STH] = unsupported,
[BGE] = unsupported,
[LDH] = unsupported,
[CMPLTI] = unsupported,
[INITDA] = unsupported,
[ORI] = ori,
[STW] = unsupported,
[BLT] = unsupported,
[LDW] = unsupported,
[CMPNEI] = unsupported,
[FLUSHDA] = unsupported,
[XORI] = xori,
[BNE] = unsupported,
[BLTU] = unsupported,
[LDWIO] = unsupported,
[R_TYPE] = handle_r_type_instr,
[FLUSHD] = unsupported,
[XORHI] = unsupported,
};
instruction_handler instruction_get_handler(uint32_t code)
{
uint32_t op = get_opcode(code);
if (unlikely(op >= I_TYPE_COUNT))
return NULL;
return i_type_instr_handlers[op];
}
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