copy the rest of the logic
This commit is contained in:
2
build.sh
2
build.sh
@@ -17,7 +17,7 @@ if command -v pkg-config >/dev/null; then
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LIBELF_FLAGS=$(pkg-config --cflags --libs libelf 2>/dev/null)
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if [ $? -eq 0 ]; then
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echo "building riscv64..."
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c++ $COMMON -o riscv64 riscv64.cc $LIBELF_FLAGS
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c++ -std=c++20 $COMMON -o riscv64 riscv64.cc $LIBELF_FLAGS
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else
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echo "libelf not found - skipping riscv64..."
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fi
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823
riscv64.cc
823
riscv64.cc
@@ -1,7 +1,9 @@
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// https://docs.riscv.org/reference/isa/unpriv/rv-32-64g.html
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// https://riscv.org/wp-content/uploads/2024/12/riscv-calling.pdf
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#include <algorithm>
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#include <array>
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#include <bit>
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#include <cstring>
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#include <fstream>
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#include <gelf.h>
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@@ -9,6 +11,55 @@
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#include <libelf.h>
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#include <vector>
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// TODO: dont use macros now that we're in an actual language
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#define PARSE_I_INS(ins) \
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u8 rd = (ins >> 7) & 0b11111; \
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u8 funct3 = (ins >> 12) & 0b111; \
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u8 rs1 = (ins >> 15) & 0b11111; \
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i32 imm = ((i32)ins) >> 20
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#define PARSE_R_INS(ins) \
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u8 rd = (ins >> 7) & 0b11111; \
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u8 funct3 = (ins >> 12) & 0b111; \
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u8 rs1 = (ins >> 15) & 0b11111; \
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u8 rs2 = (ins >> 20) & 0b11111; \
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i32 funct7 = ((i32)ins) >> 25
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#define PARSE_B_INS(ins) \
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u8 funct3 = (ins >> 12) & 0b111; \
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u8 rs1 = (ins >> 15) & 0b11111; \
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u8 rs2 = (ins >> 20) & 0b11111; \
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i32 imm_12 = (ins >> 31) & 0b1; \
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i32 imm_10_5 = (ins >> 25) & 0b111111; \
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i32 imm_4_1 = (ins >> 8) & 0b1111; \
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i32 imm_11 = (ins >> 7) & 0b1; \
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i32 imm = \
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(imm_12 << 12) | (imm_11 << 11) | (imm_10_5 << 5) | (imm_4_1 << 1); \
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imm = (imm << 19) >> 19
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#define PARSE_S_INS(ins) \
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u8 funct3 = (ins >> 12) & 0b111; \
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u8 rs1 = (ins >> 15) & 0b11111; \
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u8 rs2 = (ins >> 20) & 0b11111; \
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i32 imm_11_5 = (ins >> 25) & 0b1111111; \
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i32 imm_4_0 = (ins >> 7) & 0b11111; \
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i32 imm = (imm_11_5 << 5) | imm_4_0; \
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imm = (imm << 20) >> 20
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#define PARSE_J_INS(ins) \
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u8 rd = (ins >> 7) & 0b11111; \
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i32 imm_20 = (ins >> 31) & 0b1; \
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i32 imm_10_1 = (ins >> 21) & 0b1111111111; \
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i32 imm_11 = (ins >> 20) & 0b1; \
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i32 imm_19_12 = (ins >> 12) & 0b11111111; \
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i32 imm = \
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(imm_20 << 20) | (imm_19_12 << 12) | (imm_11 << 11) | (imm_10_1 << 1); \
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imm = (imm << 11) >> 11
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#define PARSE_U_INS(ins) \
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u8 rd = (ins >> 7) & 0b11111; \
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i32 imm = ins >> 12
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using i8 = int8_t;
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using i16 = int16_t;
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using i32 = int32_t;
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@@ -17,7 +68,9 @@ using u8 = uint8_t;
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using u16 = uint16_t;
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using u32 = uint32_t;
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using u64 = uint64_t;
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static_assert(sizeof(size_t) == sizeof(u64), "size_t must be 64-bit");
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static_assert(sizeof(size_t) == sizeof(u64), "u64 must be 64-bit");
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static_assert(std::endian::native == std::endian::little,
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"Big endianness not supported");
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static constexpr u64 MEMORY_SIZE = 20 * 1024 * 1024; // should be enough
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@@ -47,17 +100,770 @@ public:
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GElf_Phdr phdr;
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gelf_getphdr(elf, i, &phdr);
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if (phdr.p_type == PT_LOAD) {
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memcpy(m_memory.data() + phdr.p_vaddr, exe_bytes.data() + phdr.p_offset,
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phdr.p_filesz);
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std::copy_n(exe_bytes.data() + phdr.p_offset, phdr.p_filesz,
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m_memory.data() + phdr.p_vaddr);
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}
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}
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elf_end(elf);
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}
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void disassemble_all() {
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for (m_pc = m_code_section.offset;
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m_pc < m_code_section.offset + m_code_section.size; m_pc += 4) {
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disassemble_one();
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}
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}
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void disassemble_one() {
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u32 ins;
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std::memcpy(&ins, m_memory.data() + m_pc, sizeof(ins));
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u16 opcode = ins & 0b1111111;
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// https://stackoverflow.com/questions/62939410/how-can-i-find-out-the-instruction-format-of-a-risc-v-instruction
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switch (opcode) {
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case 0b1100011: {
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PARSE_B_INS(ins);
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if (funct3 == 0b000) {
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printf("beq %s, %s, %d\n", REGS[rs1], REGS[rs2], imm);
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} else if (funct3 == 0b001) {
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printf("bne %s, %s, %d\n", REGS[rs1], REGS[rs2], imm);
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} else if (funct3 == 0b100) {
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printf("blt %s, %s, %d\n", REGS[rs1], REGS[rs2], imm);
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} else if (funct3 == 0b101) {
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printf("bge %s, %s, %d\n", REGS[rs1], REGS[rs2], imm);
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} else if (funct3 == 0b110) {
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printf("bltu %s, %s, %d\n", REGS[rs1], REGS[rs2], imm);
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} else if (funct3 == 0b111) {
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printf("bgeu %s, %s, %d\n", REGS[rs1], REGS[rs2], imm);
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} else {
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fprintf(stderr, "B-type: unrecognized funct3: %03b\n", funct3);
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exit(1);
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}
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}; break;
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case 0b0010011: {
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PARSE_I_INS(ins);
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if (funct3 == 0b000) {
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printf("addi %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
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} else if (funct3 == 0b001) {
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u32 shamt = (ins >> 20) & 0b111111;
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u32 funct6 = (ins >> 26) & 0b111111;
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if (funct6 == 0b000000) {
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printf("slli %s, %s, %d\n", REGS[rd], REGS[rs1], shamt);
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} else {
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fprintf(stderr, "I-type 1: funct3=001: unrecognized funct6: %b\n",
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funct6);
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exit(1);
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}
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} else if (funct3 == 0b010) {
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printf("slti %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
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} else if (funct3 == 0b011) {
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printf("sltiu %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
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} else if (funct3 == 0b100) {
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printf("xori %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
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} else if (funct3 == 0b101) {
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// of course this one just has to be different
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u32 shamt = (ins >> 20) & 0b111111;
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u32 funct6 = (ins >> 26) & 0b111111;
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if (funct6 == 0b000000) {
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printf("srli %s, %s, %d\n", REGS[rd], REGS[rs1], shamt);
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} else if (funct6 == 0b010000) {
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printf("srai %s, %s, %d\n", REGS[rd], REGS[rs1], shamt);
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} else {
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fprintf(stderr, "I-type 1: funct3=101: unrecognized funct6: %b\n",
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funct6);
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exit(1);
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}
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} else if (funct3 == 0b110) {
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printf("ori %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
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} else if (funct3 == 0b111) {
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printf("andi %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
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} else {
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fprintf(stderr, "I-type 1: unrecognized funct3: %03b\n", funct3);
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exit(1);
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}
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}; break;
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case 0b0000011: {
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PARSE_I_INS(ins);
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if (funct3 == 0b000) {
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printf("lb %s, %d(%s)\n", REGS[rd], imm, REGS[rs1]);
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} else if (funct3 == 0b001) {
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printf("lh %s, %d(%s)\n", REGS[rd], imm, REGS[rs1]);
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} else if (funct3 == 0b010) {
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printf("lw %s, %d(%s)\n", REGS[rd], imm, REGS[rs1]);
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} else if (funct3 == 0b011) {
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printf("ld %s, %d(%s)\n", REGS[rd], imm, REGS[rs1]);
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} else if (funct3 == 0b100) {
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printf("lbu %s, %d(%s)\n", REGS[rd], imm, REGS[rs1]);
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} else if (funct3 == 0b101) {
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printf("lhu %s, %d(%s)\n", REGS[rd], imm, REGS[rs1]);
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} else if (funct3 == 0b110) {
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printf("lwu %s, %d(%s)\n", REGS[rd], imm, REGS[rs1]);
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} else {
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fprintf(stderr, "I-type 2: unrecognized funct3: %03b\n", funct3);
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exit(1);
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}
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}; break;
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case 0b1100111: {
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PARSE_I_INS(ins);
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printf("jalr %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
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}; break;
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case 0b1110011: {
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PARSE_I_INS(ins);
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if (funct3 == 0b000) {
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if (imm == 0) {
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printf("ecall\n");
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} else {
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fprintf(stderr, "I-type 4: funct3=000 unrecognized imm: %b\n", imm);
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exit(1);
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}
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} else {
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fprintf(stderr, "I-type 4: unrecognized funct3: %03b\n", funct3);
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exit(1);
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}
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}; break;
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case 0b1101111: {
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PARSE_J_INS(ins);
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printf("jal %s, %d\n", REGS[rd], imm);
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}; break;
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case 0b0110011: {
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PARSE_R_INS(ins);
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if (funct3 == 0b000) {
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if (funct7 == 0b0000000) {
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printf("add %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct7 == 0b0100000) {
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printf("sub %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct7 == 0b0000001) {
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printf("mul %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else {
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fprintf(stderr, "R-type 1: funct3=0b000: unrecognized funct7: %b\n",
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funct7);
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exit(1);
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}
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} else if (funct3 == 0b001) {
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if (funct7 == 0b0000000) {
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printf("sll %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct7 == 0b0000001) {
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printf("mulh %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else {
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fprintf(stderr, "R-type 1: funct3=0b001: unrecognized funct7: %b\n",
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funct7);
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exit(1);
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}
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} else if (funct3 == 0b010) {
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if (funct7 == 0b0000000) {
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printf("slt %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else {
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fprintf(stderr, "R-type 1: funct3=0b010: unrecognized funct7: %b\n",
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funct7);
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exit(1);
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}
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} else if (funct3 == 0b011) {
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if (funct7 == 0b0000000) {
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printf("sltu %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct7 == 0b0000001) {
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printf("mulhu %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else {
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fprintf(stderr, "R-type 1: funct3=0b011: unrecognized funct7: %b\n",
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funct7);
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exit(1);
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}
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} else if (funct3 == 0b100) {
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if (funct7 == 0b0000000) {
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printf("xor %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct7 == 0b0000001) {
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printf("div %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else {
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fprintf(stderr, "R-type 1: funct3=0b100: unrecognized funct7: %b\n",
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funct7);
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exit(1);
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}
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} else if (funct3 == 0b101) {
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if (funct7 == 0b0000000) {
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printf("srl %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct7 == 0b0000001) {
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printf("divu %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct7 == 0b0100000) {
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printf("sra %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else {
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fprintf(stderr, "R-type 1: funct3=0b101: unrecognized funct7: %b\n",
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funct7);
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exit(1);
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}
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} else if (funct3 == 0b110) {
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if (funct7 == 0b0000001) {
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printf("rem %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct7 == 0b0000000) {
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printf("or %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else {
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fprintf(stderr, "R-type 1: funct3=0b110: unrecognized funct7: %b\n",
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funct7);
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exit(1);
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}
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} else if (funct3 == 0b111) {
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if (funct7 == 0b000) {
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printf("and %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct7 == 0b001) {
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printf("remu %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else {
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fprintf(stderr, "R-type 1: funct3=0b111: unrecognized funct7: %b\n",
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funct7);
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exit(1);
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}
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} else {
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fprintf(stderr, "R-type 1: unrecognized funct3: %03b\n", funct3);
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exit(1);
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}
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}; break;
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case 0b0101111:
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fprintf(stderr, "A extension not implemented yet.\n");
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exit(1);
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case 0b0111011: {
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PARSE_R_INS(ins);
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if (funct3 == 0b000) {
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if (funct7 == 0b0000000) {
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printf("addw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct7 == 0b0100000) {
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printf("subw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
|
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} else if (funct7 == 0b0000001) {
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printf("mulw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
|
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} else {
|
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fprintf(stderr, "R-type 3: funct3=000: unrecognized funct7: %b\n",
|
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funct7);
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exit(1);
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}
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} else if (funct3 == 0b001) {
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printf("sllw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct3 == 0b100) {
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printf("divw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct3 == 0b101) {
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if (funct7 == 0b0000000) {
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printf("srlw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct7 == 0b0100000) {
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printf("sraw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct7 == 0b0000001) {
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printf("divuw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
|
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} else {
|
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fprintf(stderr, "R-type 3: funct3=101: unrecognized funct7: %b\n",
|
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funct7);
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exit(1);
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}
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} else if (funct3 == 0b110) {
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printf("remw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
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} else if (funct3 == 0b111) {
|
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printf("remuw %s, %s, %s\n", REGS[rd], REGS[rs1], REGS[rs2]);
|
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} else {
|
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fprintf(stderr, "R-type 3: unrecognized funct3: %03b\n", funct3);
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exit(1);
|
||||
}
|
||||
}; break;
|
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case 0b0011011: {
|
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u8 funct3 = (ins >> 12) & 0b111;
|
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if (funct3 == 0b000) {
|
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PARSE_I_INS(ins);
|
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printf("addiw %s, %s, %d\n", REGS[rd], REGS[rs1], imm);
|
||||
} else if (funct3 == 0b001) {
|
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PARSE_R_INS(ins);
|
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printf("slliw %s, %s, %d\n", REGS[rd], REGS[rs1], rs2);
|
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} else if (funct3 == 0b101) {
|
||||
PARSE_R_INS(ins);
|
||||
if (funct7 == 0b0000000) {
|
||||
printf("srliw %s, %s, %d\n", REGS[rd], REGS[rs1], rs2);
|
||||
} else if (funct7 == 0b0100000) {
|
||||
printf("sraiw %s, %s, %d\n", REGS[rd], REGS[rs1], rs2);
|
||||
} else {
|
||||
fprintf(stderr, "R-type 4: funct3=101: unrecognized funct7: %b\n",
|
||||
funct7);
|
||||
exit(1);
|
||||
}
|
||||
} else {
|
||||
fprintf(stderr, "R-type 4: unrecognized funct3: %03b\n", funct3);
|
||||
exit(1);
|
||||
}
|
||||
}; break;
|
||||
case 0b0100111: {
|
||||
fprintf(stderr, "F extension not implemented yet.\n");
|
||||
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 dump() {
|
||||
std::cout << "REGS:";
|
||||
for (u64 i = 0; i < 32; i++) {
|
||||
std::cout << " " << m_regs[i];
|
||||
}
|
||||
std::cout << "\n";
|
||||
}
|
||||
|
||||
void execute() {
|
||||
m_pc = m_code_section.entrypoint;
|
||||
|
||||
m_regs[2] = MEMORY_SIZE - 1024; // set the stack pointer
|
||||
|
||||
while (m_pc < m_code_section.offset + m_code_section.size) {
|
||||
m_regs[0] = 0; // clear the zero register
|
||||
|
||||
u32 ins;
|
||||
std::memcpy(&ins, m_memory.data() + m_pc, sizeof(ins));
|
||||
|
||||
u16 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) { // beq
|
||||
if (m_regs[rs1] == m_regs[rs2]) {
|
||||
m_pc += imm;
|
||||
continue;
|
||||
}
|
||||
} else if (funct3 == 0b001) { // bne
|
||||
if (m_regs[rs1] != m_regs[rs2]) {
|
||||
m_pc += imm;
|
||||
continue;
|
||||
}
|
||||
} else if (funct3 == 0b101) { // bge
|
||||
if (m_regs[rs1] >= m_regs[rs2]) {
|
||||
m_pc += imm;
|
||||
continue;
|
||||
}
|
||||
} else if (funct3 == 0b100) { // blt
|
||||
if (m_regs[rs1] < m_regs[rs2]) {
|
||||
m_pc += imm;
|
||||
continue;
|
||||
}
|
||||
} else if (funct3 == 0b110) { // bltu
|
||||
if ((u64)m_regs[rs1] < (u64)m_regs[rs2]) {
|
||||
m_pc += imm;
|
||||
continue;
|
||||
}
|
||||
} else {
|
||||
fprintf(stderr, "B-type: unrecognized funct3: %03b\n", funct3);
|
||||
exit(1);
|
||||
}
|
||||
}; break;
|
||||
case 0b0010011: {
|
||||
PARSE_I_INS(ins);
|
||||
|
||||
if (funct3 == 0b000) { // addi
|
||||
m_regs[rd] = m_regs[rs1] + imm;
|
||||
} else if (funct3 == 0b001) { // slli
|
||||
u32 shamt = (ins >> 20) & 0b111111;
|
||||
u32 funct6 = (ins >> 26) & 0b111111;
|
||||
|
||||
if (funct6 == 0b000000) {
|
||||
m_regs[rd] = m_regs[rs1] << shamt;
|
||||
} else {
|
||||
fprintf(stderr, "I-type 1: funct3=001: unrecognized funct6: %b\n",
|
||||
funct6);
|
||||
exit(1);
|
||||
}
|
||||
} else if (funct3 == 0b011) { // sltiu
|
||||
m_regs[rd] = ((u64)m_regs[rs1] < (u64)(i64)imm) ? 1 : 0;
|
||||
} else if (funct3 == 0b100) { // xori
|
||||
m_regs[rd] = m_regs[rs1] ^ imm;
|
||||
} else if (funct3 == 0b101) {
|
||||
// of course this one just has to be different
|
||||
u32 shamt = (ins >> 20) & 0b111111;
|
||||
u32 funct6 = (ins >> 26) & 0b111111;
|
||||
|
||||
if (funct6 == 0b000000) { // srli
|
||||
m_regs[rd] = (u64)m_regs[rs1] >> shamt;
|
||||
} else if (funct6 == 0b010000) { // srai
|
||||
m_regs[rd] = (i64)m_regs[rs1] >> shamt;
|
||||
} else {
|
||||
fprintf(stderr, "I-type 1: funct3=101: unrecognized funct6: %b\n",
|
||||
funct6);
|
||||
exit(1);
|
||||
}
|
||||
} else if (funct3 == 0b111) {
|
||||
m_regs[rd] = m_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) { // lb
|
||||
m_regs[rd] = (i8)m_memory[m_regs[rs1] + imm];
|
||||
} else if (funct3 == 0b001) { // lh
|
||||
m_regs[rd] = *(i16 *)&m_memory[m_regs[rs1] + imm];
|
||||
} else if (funct3 == 0b010) { // lw
|
||||
m_regs[rd] = *(i32 *)&m_memory[m_regs[rs1] + imm];
|
||||
} else if (funct3 == 0b011) { // ld
|
||||
m_regs[rd] = *(u64 *)&m_memory[m_regs[rs1] + imm];
|
||||
} else if (funct3 == 0b100) { // lbu
|
||||
m_regs[rd] = m_memory[m_regs[rs1] + imm];
|
||||
} else {
|
||||
fprintf(stderr, "I-type 2: unrecognized funct3: %03b\n", funct3);
|
||||
exit(1);
|
||||
}
|
||||
}; break;
|
||||
case 0b1100111: { // jalr
|
||||
PARSE_I_INS(ins);
|
||||
u64 target = (m_regs[rs1] + imm) & ~(u64)1;
|
||||
m_regs[rd] = m_pc + 4;
|
||||
m_pc = target;
|
||||
continue;
|
||||
}; break;
|
||||
case 0b1110011: {
|
||||
PARSE_I_INS(ins);
|
||||
|
||||
if (funct3 == 0b000) {
|
||||
if (imm == 0) { // ecall
|
||||
// https://jborza.com/post/2021-05-11-riscv-linux-syscalls/
|
||||
switch (m_regs[17]) {
|
||||
case 63: { // read
|
||||
if (m_regs[10] != 0) {
|
||||
fprintf(stderr, "read syscall implemented only for stdin.\n");
|
||||
exit(1);
|
||||
}
|
||||
|
||||
u64 start = m_regs[11];
|
||||
u64 count = m_regs[12];
|
||||
u64 bytes_read = 0;
|
||||
|
||||
for (u64 i = 0; i < count; i++) {
|
||||
int c = getchar();
|
||||
if (c == EOF)
|
||||
break;
|
||||
m_memory[start + i] = (u8)c;
|
||||
bytes_read++;
|
||||
if (c == '\n')
|
||||
break;
|
||||
}
|
||||
|
||||
m_regs[10] = bytes_read;
|
||||
}; break;
|
||||
case 64: { // write
|
||||
if (m_regs[10] != 1) {
|
||||
fprintf(stderr, "write syscall implemented only for stdout.\n");
|
||||
exit(1);
|
||||
}
|
||||
|
||||
u64 start = m_regs[11];
|
||||
u64 end = m_regs[11] + m_regs[12];
|
||||
|
||||
for (u64 i = start; i < end; i++) {
|
||||
putchar(m_memory[i]);
|
||||
}
|
||||
}; break;
|
||||
case 93: { // exit
|
||||
printf("Program exited with code %lu.\n", m_regs[10]);
|
||||
return;
|
||||
}; break;
|
||||
case 169: { // gettimeofday
|
||||
// TODO: actually return the time
|
||||
i64 tv_addr = m_regs[10];
|
||||
i64 tz_addr = m_regs[11];
|
||||
|
||||
u8 tv_buf[16] = {
|
||||
0xD2, 0x02, 0x96, 0x49,
|
||||
0x00, 0x00, 0x00, 0x00, // tv_sec = 1234567890
|
||||
0x00, 0x00, 0x00, 0x00,
|
||||
0x00, 0x00, 0x00, 0x00, // tv_usec = 0
|
||||
};
|
||||
memcpy(&m_memory[tv_addr], tv_buf, 16);
|
||||
|
||||
memset(&m_memory[tz_addr], 0, 8);
|
||||
|
||||
m_regs[10] = 0;
|
||||
}; break;
|
||||
default:
|
||||
fprintf(stderr, "Unimplemented syscall: %lu\n", m_regs[17]);
|
||||
exit(1);
|
||||
}
|
||||
break;
|
||||
} else {
|
||||
fprintf(stderr, "I-type 4: funct3=000 unrecognized imm: %b\n", imm);
|
||||
exit(1);
|
||||
};
|
||||
break;
|
||||
} else {
|
||||
fprintf(stderr, "I-type 4: unrecognized funct3: %03b\n", funct3);
|
||||
exit(1);
|
||||
}
|
||||
}; break;
|
||||
case 0b1101111: { // jal
|
||||
PARSE_J_INS(ins);
|
||||
m_regs[rd] = m_pc + 4;
|
||||
m_pc += imm;
|
||||
continue;
|
||||
}; break;
|
||||
case 0b0110011: {
|
||||
PARSE_R_INS(ins);
|
||||
if (funct3 == 0b000) {
|
||||
if (funct7 == 0b0000000) { // add
|
||||
m_regs[rd] = m_regs[rs1] + m_regs[rs2];
|
||||
} else if (funct7 == 0b0100000) { // sub
|
||||
m_regs[rd] = m_regs[rs1] - m_regs[rs2];
|
||||
} else if (funct7 == 0b0000001) { // mul
|
||||
m_regs[rd] = m_regs[rs1] * m_regs[rs2];
|
||||
} else {
|
||||
fprintf(stderr, "R-type 1: funct3=0b000: unrecognized funct7: %b\n",
|
||||
funct7);
|
||||
exit(1);
|
||||
}
|
||||
} else if (funct3 == 0b001) {
|
||||
if (funct7 == 0b0000001) { // mulh
|
||||
i64 a_hi = m_regs[rs1] >> 32;
|
||||
i64 b_hi = m_regs[rs2] >> 32;
|
||||
u64 a_lo = (u32)m_regs[rs1];
|
||||
u64 b_lo = (u32)m_regs[rs2];
|
||||
u64 p0 = a_lo * b_lo;
|
||||
i64 p1 = a_hi * b_lo;
|
||||
i64 p2 = b_hi * a_lo;
|
||||
i64 p3 = a_hi * b_hi;
|
||||
i64 carry = (p0 >> 32);
|
||||
i64 mid = p1 + p2 + carry;
|
||||
m_regs[rd] = p3 + (mid >> 32);
|
||||
} else {
|
||||
fprintf(stderr, "R-type 1: funct3=0b001: unrecognized funct7: %b\n",
|
||||
funct7);
|
||||
exit(1);
|
||||
}
|
||||
} else if (funct3 == 0b010) {
|
||||
if (funct7 == 0b0000000) { // slt
|
||||
m_regs[rd] = (m_regs[rs1] < m_regs[rs2]) ? 1 : 0;
|
||||
} else {
|
||||
fprintf(stderr, "R-type 1: funct3=0b010: unrecognized funct7: %b\n",
|
||||
funct7);
|
||||
exit(1);
|
||||
}
|
||||
} else if (funct3 == 0b011) {
|
||||
if (funct7 == 0b0000000) { // sltu
|
||||
m_regs[rd] = ((u64)m_regs[rs1] < (u64)m_regs[rs2]) ? 1 : 0;
|
||||
} else if (funct7 == 0b0000001) { // mulhu
|
||||
u64 a = m_regs[rs1];
|
||||
u64 b = m_regs[rs2];
|
||||
u64 a_lo = a & 0xffffffff;
|
||||
u64 a_hi = a >> 32;
|
||||
u64 b_lo = b & 0xffffffff;
|
||||
u64 b_hi = b >> 32;
|
||||
u64 lo_lo = a_lo * b_lo;
|
||||
u64 hi_lo = a_hi * b_lo;
|
||||
u64 lo_hi = a_lo * b_hi;
|
||||
u64 hi_hi = a_hi * b_hi;
|
||||
u64 mid =
|
||||
(lo_lo >> 32) + (hi_lo & 0xffffffff) + (lo_hi & 0xffffffff);
|
||||
m_regs[rd] = hi_hi + (hi_lo >> 32) + (lo_hi >> 32) + (mid >> 32);
|
||||
} else {
|
||||
fprintf(stderr, "R-type 1: funct3=0b011: unrecognized funct7: %b\n",
|
||||
funct7);
|
||||
exit(1);
|
||||
}
|
||||
} else if (funct3 == 0b100) {
|
||||
if (funct7 == 0b0000000) { // xor
|
||||
m_regs[rd] = m_regs[rs1] ^ m_regs[rs2];
|
||||
} else if (funct7 == 0b0000001) { // div
|
||||
if (m_regs[rs2] == 0) {
|
||||
m_regs[rd] = -1;
|
||||
} else {
|
||||
m_regs[rd] = m_regs[rs1] / m_regs[rs2];
|
||||
}
|
||||
} else {
|
||||
fprintf(stderr, "R-type 1: funct3=0b100: unrecognized funct7: %b\n",
|
||||
funct7);
|
||||
exit(1);
|
||||
}
|
||||
} else if (funct3 == 0b110) {
|
||||
if (funct7 == 0b0000001) { // rem
|
||||
if (m_regs[rs2] == 0) {
|
||||
m_regs[rd] = m_regs[rs1];
|
||||
} else {
|
||||
m_regs[rd] = m_regs[rs1] % m_regs[rs2];
|
||||
}
|
||||
} else if (funct7 == 0b0000000) { // or
|
||||
m_regs[rd] = m_regs[rs1] | m_regs[rs2];
|
||||
} else {
|
||||
fprintf(stderr, "R-type 1: funct3=0b110: unrecognized funct7: %b\n",
|
||||
funct7);
|
||||
exit(1);
|
||||
}
|
||||
} else if (funct3 == 0b111) {
|
||||
if (funct7 == 0b000) { // and
|
||||
m_regs[rd] = m_regs[rs1] & m_regs[rs2];
|
||||
} else if (funct7 == 0b001) { // remu
|
||||
if (m_regs[rs2] == 0) {
|
||||
m_regs[rd] = m_regs[rs1];
|
||||
} else {
|
||||
m_regs[rd] = (u64)m_regs[rs1] % (u64)m_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, "A extension not implemented yet.\n");
|
||||
exit(1);
|
||||
}; break;
|
||||
case 0b0111011: {
|
||||
PARSE_R_INS(ins);
|
||||
if (funct3 == 0b000) {
|
||||
if (funct7 == 0b0000000) { // addw
|
||||
m_regs[rd] = (i32)(m_regs[rs1] + m_regs[rs2]);
|
||||
} else if (funct7 == 0b0100000) { // subw
|
||||
m_regs[rd] = (i32)(m_regs[rs1] - m_regs[rs2]);
|
||||
} else if (funct7 == 0b0000001) { // mulw
|
||||
m_regs[rd] = (i32)(m_regs[rs1] * m_regs[rs2]);
|
||||
} else {
|
||||
fprintf(stderr, "R-type 3: funct3=000: unrecognized funct7: %b\n",
|
||||
funct7);
|
||||
exit(1);
|
||||
}
|
||||
} else if (funct3 == 0b001) {
|
||||
if (funct7 == 0b0000000) { // sllw
|
||||
m_regs[rd] =
|
||||
(i32)(u32)((u32)m_regs[rs1] << ((u32)m_regs[rs2] & 0b11111));
|
||||
} else {
|
||||
fprintf(stderr, "R-type 3: funct3=001: unrecognized funct7: %b\n",
|
||||
funct7);
|
||||
exit(1);
|
||||
}
|
||||
} else if (funct3 == 0b100) { // divw
|
||||
i32 a = m_regs[rs1];
|
||||
i32 b = m_regs[rs2];
|
||||
if (b == 0) {
|
||||
m_regs[rd] = (u64)(i64)(-1);
|
||||
} else {
|
||||
m_regs[rd] = (i64)(a / b);
|
||||
}
|
||||
} else if (funct3 == 0b101) {
|
||||
if (funct7 == 0b0000000) { // srlw
|
||||
m_regs[rd] =
|
||||
(i32)((u32)m_regs[rs1] >> ((u32)m_regs[rs2] & 0b11111));
|
||||
} else if (funct7 == 0b0100000) { // sraw
|
||||
m_regs[rd] = ((i32)m_regs[rs1]) >> ((u32)m_regs[rs2] & 0b11111);
|
||||
} else if (funct7 == 0b0000001) { // divuw
|
||||
if (m_regs[rs2] == 0) {
|
||||
m_regs[rd] = -1LL;
|
||||
} else {
|
||||
m_regs[rd] = (i32)((u32)m_regs[rs1] / (u32)m_regs[rs2]);
|
||||
}
|
||||
} else {
|
||||
fprintf(stderr, "R-type 3: funct3=101: unrecognized funct7: %b\n",
|
||||
funct7);
|
||||
exit(1);
|
||||
}
|
||||
} else if (funct3 == 0b111) { // remuw
|
||||
if (m_regs[rs2] == 0) {
|
||||
m_regs[rd] = (i32)m_regs[rs1];
|
||||
} else {
|
||||
m_regs[rd] = (i32)((u32)m_regs[rs1] % (u32)m_regs[rs2]);
|
||||
}
|
||||
} else {
|
||||
fprintf(stderr, "R-type 3: unrecognized funct3: %03b\n", funct3);
|
||||
exit(1);
|
||||
}
|
||||
}; break;
|
||||
case 0b0011011: {
|
||||
PARSE_I_INS(ins);
|
||||
if (funct3 == 0b000) { // addiw
|
||||
m_regs[rd] = (i32)m_regs[rs1] + (i32)imm;
|
||||
} else if (funct3 == 0b001) {
|
||||
u32 shamt = (ins >> 20) & 0b11111;
|
||||
m_regs[rd] = (i32)m_regs[rs1] << shamt;
|
||||
} else if (funct3 == 0b101) {
|
||||
PARSE_R_INS(ins);
|
||||
if (funct7 == 0b0000000) { // srliw
|
||||
m_regs[rd] = (i32)((u32)m_regs[rs1] >> rs2);
|
||||
} else if (funct7 == 0b0100000) { // sraiw
|
||||
m_regs[rd] = (i32)m_regs[rs1] >> rs2;
|
||||
} else {
|
||||
fprintf(stderr, "R-type 4: funct3=101: unrecognized funct7: %b\n",
|
||||
funct7);
|
||||
exit(1);
|
||||
}
|
||||
} else {
|
||||
fprintf(stderr, "R-type 4: unrecognized funct3: %03b\n", funct3);
|
||||
exit(1);
|
||||
}
|
||||
}; break;
|
||||
case 0b0100011: {
|
||||
PARSE_S_INS(ins);
|
||||
|
||||
if (funct3 == 0b000) { // sb
|
||||
u64 addr = m_regs[rs1] + imm;
|
||||
m_memory[addr] = m_regs[rs2];
|
||||
} else if (funct3 == 0b001) { // sh
|
||||
u64 addr = m_regs[rs1] + imm;
|
||||
*(u16 *)(&m_memory[addr]) = m_regs[rs2];
|
||||
} else if (funct3 == 0b010) { // sw
|
||||
u64 addr = m_regs[rs1] + imm;
|
||||
*(u32 *)(&m_memory[addr]) = m_regs[rs2];
|
||||
} else if (funct3 == 0b011) { // sd
|
||||
u64 addr = m_regs[rs1] + imm;
|
||||
// take this rust
|
||||
*(u64 *)(&m_memory[addr]) = m_regs[rs2];
|
||||
} else {
|
||||
fprintf(stderr, "S-type: unrecognized funct3: %03b\n", funct3);
|
||||
exit(1);
|
||||
}
|
||||
}; break;
|
||||
case 0b0110111: { // lui
|
||||
PARSE_U_INS(ins);
|
||||
m_regs[rd] = (i64)(i32)(imm << 12);
|
||||
}; break;
|
||||
case 0b0010111: { // auipc
|
||||
PARSE_U_INS(ins);
|
||||
m_regs[rd] = m_pc + ((i64)imm << 12);
|
||||
}; break;
|
||||
default:
|
||||
fprintf(stderr, "Unrecognized opcode: %07b\n", opcode);
|
||||
exit(1);
|
||||
}
|
||||
|
||||
m_pc += 4;
|
||||
}
|
||||
}
|
||||
|
||||
private:
|
||||
std::vector<u8> m_memory = std::vector<u8>(MEMORY_SIZE, 0);
|
||||
u64 m_pc;
|
||||
std::array<i64, 32> m_regs = {0};
|
||||
std::array<i64, 32> m_regs{};
|
||||
Section m_code_section;
|
||||
|
||||
static Section get_code_section(Elf *elf, GElf_Ehdr ehdr) {
|
||||
@@ -117,10 +923,11 @@ int main(int argc, char *argv[]) {
|
||||
|
||||
RISCV64 r(exe_bytes);
|
||||
|
||||
exe_bytes = {};
|
||||
exe_bytes.clear();
|
||||
exe_bytes.shrink_to_fit();
|
||||
|
||||
// r.disassemble_all();
|
||||
// printf("END DISASSEMBLY\n");
|
||||
r.disassemble_all();
|
||||
printf("END DISASSEMBLY\n");
|
||||
|
||||
// r.execute();
|
||||
r.execute();
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user