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split to riscv64_dis.h

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Antoni Piasecki
2026-03-01 11:27:30 +01:00
parent 71743552ec
commit d7f947eb50
2 changed files with 325 additions and 322 deletions
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324
riscv64.c
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@@ -1,78 +1,14 @@
// https://docs.riscv.org/reference/isa/_attachments/riscv-unprivileged.pdf
// https://riscv.org/wp-content/uploads/2024/12/riscv-calling.pdf
#include "riscv64_dis.h"
#include <gelf.h>
#include <libelf.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define PARSE_I_INS(ins) \
uint8_t rd = (ins >> 7) & 0b11111; \
uint8_t funct3 = (ins >> 12) & 0b111; \
uint8_t rs1 = (ins >> 15) & 0b11111; \
int32_t imm = ((int32_t)ins) >> 20
#define PARSE_R_INS(ins) \
uint8_t rd = (ins >> 7) & 0b11111; \
uint8_t funct3 = (ins >> 12) & 0b111; \
uint8_t rs1 = (ins >> 15) & 0b11111; \
uint8_t rs2 = (ins >> 20) & 0b11111; \
int32_t funct7 = ((int32_t)ins) >> 25
#define PARSE_B_INS(ins) \
uint8_t funct3 = (ins >> 12) & 0b111; \
uint8_t rs1 = (ins >> 15) & 0b11111; \
uint8_t rs2 = (ins >> 20) & 0b11111; \
int32_t imm_12 = (ins >> 31) & 0b1; \
int32_t imm_10_5 = (ins >> 25) & 0b111111; \
int32_t imm_4_1 = (ins >> 8) & 0b1111; \
int32_t imm_11 = (ins >> 7) & 0b1; \
int32_t imm = \
(imm_12 << 12) | (imm_11 << 11) | (imm_10_5 << 5) | (imm_4_1 << 1); \
imm = (imm << 19) >> 19
#define PARSE_S_INS(ins) \
uint8_t funct3 = (ins >> 12) & 0b111; \
uint8_t rs1 = (ins >> 15) & 0b11111; \
uint8_t rs2 = (ins >> 20) & 0b11111; \
int32_t imm_11_5 = (ins >> 25) & 0b1111111; \
int32_t imm_4_0 = (ins >> 7) & 0b11111; \
int32_t imm = (imm_11_5 << 5) | imm_4_0; \
imm = (imm << 20) >> 20
#define PARSE_J_INS(ins) \
uint8_t rd = (ins >> 7) & 0b11111; \
int32_t imm_20 = (ins >> 31) & 0b1; \
int32_t imm_10_1 = (ins >> 21) & 0b1111111111; \
int32_t imm_11 = (ins >> 20) & 0b1; \
int32_t imm_19_12 = (ins >> 12) & 0b11111111; \
int32_t imm = \
(imm_20 << 20) | (imm_19_12 << 12) | (imm_11 << 11) | (imm_10_1 << 1); \
imm = (imm << 11) >> 11
#define PARSE_U_INS(ins) \
uint8_t rd = (ins >> 7) & 0b11111; \
int32_t imm = ins >> 12
static const char *const REGS[32] = {
const char *const REGS[32] = {
"zero", "ra", "sp", "gp", "tp", "t0", "t1", "t2", "fp", "s1", "a0",
"a1", "a2", "a3", "a4", "a5", "a6", "a7", "s2", "s3", "s4", "s5",
"s6", "s7", "s8", "s9", "s10", "s11", "t3", "t4", "t5", "t6"};
typedef struct {
size_t offset;
size_t size;
size_t entrypoint;
} Section;
typedef struct {
uint8_t *memory;
size_t pc;
int64_t regs[32];
Section code_section;
} RISCV64;
Section riscv64_get_code_section(uint8_t *exe_bytes, size_t exe_size) {
Elf *elf = elf_memory((char *)exe_bytes, exe_size);
if (!elf) {
@@ -131,262 +67,6 @@ void riscv64_dump(const RISCV64 *r) {
printf("\n");
}
void riscv64_disassemble_one(const RISCV64 *r) {
uint32_t ins;
memcpy(&ins, r->memory + r->pc, 4);
uint16_t opcode = ins & 0b1111111;
// https://stackoverflow.com/questions/62939410/how-can-i-find-out-the-instruction-format-of-a-risc-v-instruction
switch (opcode) {
case 0b1100011: {
PARSE_B_INS(ins);
if (funct3 == 0b000) {
printf("beq %s, %s, %d\n", REGS[rs1], REGS[rs2], imm);
} else if (funct3 == 0b001) {
printf("bne %s, %s, %d\n", REGS[rs1], REGS[rs2], imm);
} else if (funct3 == 0b100) {
printf("blt %s, %s, %d\n", REGS[rs1], REGS[rs2], imm);
} else if (funct3 == 0b101) {
printf("bge %s, %s, %d\n", REGS[rs1], REGS[rs2], imm);
} else if (funct3 == 0b110) {
printf("bltu %s, %s, %d\n", REGS[rs1], REGS[rs2], imm);
} else {
fprintf(stderr, "B-type: unrecognized funct3: %03b\n", funct3);
exit(1);
}
}; break;
case 0b0010011: {
PARSE_I_INS(ins);
if (funct3 == 0b000) {
printf("addi %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
} else if (funct3 == 0b001) {
uint32_t shamt = (ins >> 20) & 0b111111;
uint32_t funct6 = (ins >> 26) & 0b111111;
if (funct6 == 0b000000) {
printf("slli %s, %s, %d\n", REGS[rd], REGS[rs1], shamt);
} else {
fprintf(stderr, "I-type 1: funct3=001: unrecognized funct6: %b\n",
funct6);
exit(1);
}
} else if (funct3 == 0b011) {
printf("sltiu %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
} else if (funct3 == 0b100) {
printf("xori %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
} else if (funct3 == 0b101) {
// of course this one just has to be different
uint32_t shamt = (ins >> 20) & 0b111111;
uint32_t funct6 = (ins >> 26) & 0b111111;
if (funct6 == 0b000000) {
printf("srli %s, %s, %d\n", REGS[rd], REGS[rs1], shamt);
} else if (funct6 == 0b010000) {
printf("srai %s, %s, %d\n", REGS[rd], REGS[rs1], shamt);
} else {
fprintf(stderr, "I-type 1: funct3=101: unrecognized funct6: %b\n",
funct6);
exit(1);
}
} else if (funct3 == 0b111) {
printf("andi %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
} else {
fprintf(stderr, "I-type 1: unrecognized funct3: %03b\n", funct3);
exit(1);
}
}; break;
case 0b0000011: {
PARSE_I_INS(ins);
if (funct3 == 0b000) {
printf("lb %s, %d(%s)\n", REGS[rd], imm, REGS[rs1]);
} else if (funct3 == 0b001) {
printf("lh %s, %d(%s)\n", REGS[rd], imm, REGS[rs1]);
} else if (funct3 == 0b010) {
printf("lw %s, %d(%s)\n", REGS[rd], imm, REGS[rs1]);
} else if (funct3 == 0b011) {
printf("ld %s, %d(%s)\n", REGS[rd], imm, REGS[rs1]);
} else if (funct3 == 0b100) {
printf("lbu %s, %d(%s)\n", REGS[rd], imm, REGS[rs1]);
} else {
fprintf(stderr, "I-type 2: unrecognized funct3: %03b\n", funct3);
exit(1);
}
}; break;
case 0b1100111: {
PARSE_I_INS(ins);
printf("jalr %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
}; break;
case 0b1110011: {
PARSE_I_INS(ins);
if (funct3 == 0b000) {
if (imm == 0) {
printf("ecall\n");
} else {
fprintf(stderr, "I-type 4: funct3=000 unrecognized imm: %b\n", imm);
exit(1);
}
} else {
fprintf(stderr, "I-type 4: unrecognized funct3: %03b\n", funct3);
exit(1);
}
}; break;
case 0b1101111: {
PARSE_J_INS(ins);
printf("jal %s, %d\n", REGS[rd], imm);
}; break;
case 0b0110011: {
PARSE_R_INS(ins);
if (funct3 == 0b000) {
if (funct7 == 0b0000000) {
printf("add %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else if (funct7 == 0b0100000) {
printf("sub %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else if (funct7 == 0b0000001) {
printf("mul %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else {
fprintf(stderr, "R-type 1: funct3=0b000: unrecognized funct7: %b\n",
funct7);
exit(1);
}
} else if (funct3 == 0b001) {
if (funct7 == 0b0000001) {
printf("mulh %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else {
fprintf(stderr, "R-type 1: funct3=0b001: unrecognized funct7: %b\n",
funct7);
exit(1);
}
} else if (funct3 == 0b010) {
if (funct7 == 0b0000000) {
printf("slt %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else {
fprintf(stderr, "R-type 1: funct3=0b010: unrecognized funct7: %b\n",
funct7);
exit(1);
}
} else if (funct3 == 0b011) {
if (funct7 == 0b0000000) {
printf("sltu %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else if (funct7 == 0b0000001) {
printf("mulhu %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else {
fprintf(stderr, "R-type 1: funct3=0b011: unrecognized funct7: %b\n",
funct7);
exit(1);
}
} else if (funct3 == 0b100) {
if (funct7 == 0b0000000) {
printf("xor %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else if (funct7 == 0b0000001) {
printf("div %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else {
fprintf(stderr, "R-type 1: funct3=0b100: unrecognized funct7: %b\n",
funct7);
exit(1);
}
} else if (funct3 == 0b110) {
if (funct7 == 0b0000001) {
printf("rem %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else if (funct7 == 0b0000000) {
printf("or %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else {
fprintf(stderr, "R-type 1: funct3=0b110: unrecognized funct7: %b\n",
funct7);
exit(1);
}
} else if (funct3 == 0b111) {
if (funct7 == 0b000) {
printf("and %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else {
fprintf(stderr, "R-type 1: funct3=0b111: unrecognized funct7: %b\n",
funct7);
exit(1);
}
} else {
fprintf(stderr, "R-type 1: unrecognized funct3: %03b\n", funct3);
exit(1);
}
}; break;
case 0b0101111:
fprintf(stderr, "R-type 2: unimplemented\n");
exit(1);
case 0b0111011: {
PARSE_R_INS(ins);
if (funct3 == 0b000) {
if (funct7 == 0b0000000) {
printf("addw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else if (funct7 == 0b0100000) {
printf("subw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else if (funct7 == 0b0000001) {
printf("mulw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else {
fprintf(stderr, "R-type 3: funct3=000: unrecognized funct7: %b\n",
funct7);
exit(1);
}
} else if (funct3 == 0b101) {
if (funct7 == 0b0000001) {
printf("divuw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else {
fprintf(stderr, "R-type 3: funct3=101: unrecognized funct7: %b\n",
funct7);
exit(1);
}
} else if (funct3 == 0b111) {
printf("remuw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
} else {
fprintf(stderr, "R-type 3: unrecognized funct3: %03b\n", funct3);
exit(1);
}
}; break;
case 0b0011011: {
uint8_t funct3 = (ins >> 12) & 0b111;
if (funct3 == 0b000) {
PARSE_I_INS(ins);
printf("addiw %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
} else if (funct3 == 0b001) {
PARSE_I_INS(ins);
printf("slliw %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
} else {
fprintf(stderr, "R-type 4: unrecognized funct3: %03b\n", funct3);
exit(1);
}
}; break;
case 0b0100011: {
PARSE_S_INS(ins);
if (funct3 == 0b000) {
printf("sb %s, %d(%s)\n", REGS[rs2], imm, REGS[rs1]);
} else if (funct3 == 0b001) {
printf("sh %s, %d(%s)\n", REGS[rs2], imm, REGS[rs1]);
} else if (funct3 == 0b010) {
printf("sw %s, %d(%s)\n", REGS[rs2], imm, REGS[rs1]);
} else if (funct3 == 0b011) {
printf("sd %s, %d(%s)\n", REGS[rs2], imm, REGS[rs1]);
} else {
fprintf(stderr, "S-type: unrecognized funct3: %03b\n", funct3);
exit(1);
}
}; break;
case 0b0110111: {
PARSE_U_INS(ins);
printf("lui %s, %d\n", REGS[rd], imm);
}; break;
case 0b0010111: {
PARSE_U_INS(ins);
printf("auipc %s, %d\n", REGS[rd], imm);
}; break;
default:
fprintf(stderr, "Unrecognized opcode: %07b\n", opcode);
exit(1);
}
}
void riscv64_execute(RISCV64 *r) {
r->pc = r->code_section.entrypoint;