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Some work on CSR

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This commit is contained in:
Steven Le Rouzic
2024-05-13 00:04:44 +02:00
parent f9541157b6
commit f95a85de00
12 changed files with 403 additions and 227 deletions
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336
emulator/hart.c
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@ -1,129 +1,106 @@
#include "emulator/hart.h"
#include "emulator/bits.h"
#include "emulator/instruction.h"
#include "emulator/csr.h"
#include <stdio.h>
#include <inttypes.h>
#include <assert.h>
#include <stdbool.h>
#include <string.h>
#define REG_ZERO 0
#define REG_RA 1
#define REG_SP 2
#define REG_GP 3
#define REG_TP 4
#define REG_T0 5
#define REG_T1 6
#define REG_T2 7
#define REG_S0 8
#define REG_S1 9
#define REG_A0 10
#define REG_A1 11
#define REG_A2 12
#define REG_A3 13
#define REG_A4 14
#define REG_A5 15
#define REG_A6 16
#define REG_A7 17
#define REG_S2 18
#define REG_S3 19
#define REG_S4 20
#define REG_S5 21
#define REG_S6 22
#define REG_S7 23
#define REG_S8 24
#define REG_S9 25
#define REG_S10 26
#define REG_S11 27
#define REG_T3 28
#define REG_T4 29
#define REG_T5 30
#define REG_T6 31
#define REG_ZERO 0
#define REG_RA 1
#define REG_SP 2
#define REG_GP 3
#define REG_TP 4
#define REG_T0 5
#define REG_T1 6
#define REG_T2 7
#define REG_S0 8
#define REG_S1 9
#define REG_A0 10
#define REG_A1 11
#define REG_A2 12
#define REG_A3 13
#define REG_A4 14
#define REG_A5 15
#define REG_A6 16
#define REG_A7 17
#define REG_S2 18
#define REG_S3 19
#define REG_S4 20
#define REG_S5 21
#define REG_S6 22
#define REG_S7 23
#define REG_S8 24
#define REG_S9 25
#define REG_S10 26
#define REG_S11 27
#define REG_T3 28
#define REG_T4 29
#define REG_T5 30
#define REG_T6 31
static inline uint32_t sign_extend(uint32_t word, uint32_t size)
static void handle_ecall(Hart* hart)
{
const uint32_t mask = 1U << (size - 1);
return (word ^ mask) - mask;
}
static inline uint64_t sign_extend_64(uint64_t word, uint32_t size)
static inline uint32_t load_size(Hart* hart, uint32_t address, uint32_t size)
{
const uint64_t mask = 1ULL << (size - 1);
return (word ^ mask) - mask;
if ((address & 0x80000000) == 0)
{
assert(address + size < hart->mem_size);
uint32_t value = 0;
memcpy(&value, hart->mem + address, size);
return value;
}
return 0;
}
struct Instruction
static uint32_t load_byte(Hart* hart, uint32_t address)
{
uint8_t opcode;
uint8_t rs1;
uint8_t rs2;
uint8_t rd;
uint8_t funct3;
uint8_t funct7;
uint32_t imm;
};
typedef struct Instruction Instruction;
return load_size(hart, address, 1);
}
static Instruction decode_r_type(uint32_t word)
static uint32_t load_half(Hart* hart, uint32_t address)
{
Instruction instruction = {0};
instruction.opcode = word & 0x7F;
instruction.rd = (word >> 7) & 0x1F;
instruction.funct3 = (word >> 12) & 0x07;
instruction.rs1 = (word >> 15) & 0x1F;
instruction.rs2 = (word >> 20) & 0x1F;
instruction.funct7 = word >> 25;
return instruction;
};
return load_size(hart, address, 2);
}
static Instruction decode_i_type(uint32_t word)
static uint32_t load_word(Hart* hart, uint32_t address)
{
Instruction instruction = {0};
instruction.opcode = word & 0x7F;
instruction.rd = (word >> 7) & 0x1F;
instruction.funct3 = (word >> 12) & 0x07;
instruction.rs1 = (word >> 15) & 0x1F;
instruction.imm = sign_extend(word >> 20, 12);
return instruction;
};
return load_size(hart, address, 4);
}
static Instruction decode_s_type(uint32_t word)
static inline void store_size(Hart* hart, uint32_t address, uint32_t value, uint32_t size)
{
Instruction instruction = {0};
instruction.opcode = word & 0x7F;
instruction.funct3 = (word >> 12) & 0x07;
instruction.rs1 = (word >> 15) & 0x1F;
instruction.rs2 = (word >> 20) & 0x1F;
instruction.imm = sign_extend(((word >> 7) & 0x1F) | (word >> 25), 12);
return instruction;
};
if ((address & 0x80000000) == 0)
{
assert(address + size < hart->mem_size);
memcpy(hart->mem + address, &value, size);
}
else if (address == 0x80000000)
{
fwrite(&value, 1, size, stdout);
}
}
static Instruction decode_b_type(uint32_t word)
static void store_byte(Hart* hart, uint32_t address, uint8_t value)
{
Instruction instruction = decode_s_type(word);
instruction.imm = ((instruction.imm << 11) & 0x800) | (instruction.imm & 0xfffff7ff);
return instruction;
};
store_size(hart, address, value, 1);
}
static Instruction decode_u_type(uint32_t word)
static void store_half(Hart* hart, uint32_t address, uint16_t value)
{
Instruction instruction = {0};
instruction.opcode = word & 0x7F;
instruction.rd = (word >> 7) & 0x1F;
instruction.imm = word & 0xFFFFF000;
return instruction;
};
store_size(hart, address, value, 2);
}
static Instruction decode_j_type(uint32_t word)
static void store_word(Hart* hart, uint32_t address, uint32_t value)
{
Instruction instruction = {0};
instruction.opcode = word & 0x7F;
instruction.rd = (word >> 7) & 0x1F;
instruction.imm = sign_extend(
((word & 0x80000000) >> 11) |
((word & 0x000FF000) >> 0) |
((word & 0x00100000) >> 9) |
((word & 0x7FE00000) >> 20), 21);
return instruction;
store_size(hart, address, value, 4);
}
static void execute_op_imm(Hart* hart, uint32_t instruction)
@ -338,62 +315,6 @@ static void execute_branch(Hart* hart, uint32_t instruction)
}
}
static inline uint32_t load_size(Hart* hart, uint32_t address, uint32_t size)
{
if ((address & 0x80000000) == 0)
{
assert(address + size < hart->mem_size);
uint32_t value = 0;
memcpy(&value, hart->mem + address, size);
return value;
}
return 0;
}
static uint32_t load_byte(Hart* hart, uint32_t address)
{
return load_size(hart, address, 1);
}
static uint32_t load_half(Hart* hart, uint32_t address)
{
return load_size(hart, address, 2);
}
static uint32_t load_word(Hart* hart, uint32_t address)
{
return load_size(hart, address, 4);
}
static inline void store_size(Hart* hart, uint32_t address, uint32_t value, uint32_t size)
{
if ((address & 0x80000000) == 0)
{
assert(address + size < hart->mem_size);
memcpy(hart->mem + address, &value, size);
}
else if (address == 0x80000000)
{
fwrite(&value, 1, size, stdout);
}
}
static void store_byte(Hart* hart, uint32_t address, uint8_t value)
{
store_size(hart, address, value, 1);
}
static void store_half(Hart* hart, uint32_t address, uint16_t value)
{
store_size(hart, address, value, 2);
}
static void store_word(Hart* hart, uint32_t address, uint32_t value)
{
store_size(hart, address, value, 4);
}
static void execute_load(Hart* hart, uint32_t instruction)
{
const Instruction inst = decode_i_type(instruction);
@ -462,43 +383,6 @@ static void execute_misc_mem(Hart* hart, uint32_t instruction)
}
}
static void handle_ecall(Hart* hart)
{
if (hart->regs[REG_A0] == 0)
{
hart->halted = true;
}
}
static uint32_t crs_read(Hart* hart, uint16_t id)
{
// @Todo
return 0;
}
static void crs_write(Hart* hart, uint16_t id, uint32_t new_value)
{
// @Todo
}
static uint32_t crs_read_write(Hart* hart, uint16_t id, uint32_t new_value)
{
// @Todo
return 0;
}
static uint32_t crs_read_clear(Hart* hart, uint16_t id, uint32_t mask)
{
// @Todo
return 0;
}
static uint32_t crs_read_set(Hart* hart, uint16_t id, uint32_t mask)
{
// @Todo
return 0;
}
static void execute_system(Hart* hart, uint32_t instruction)
{
const Instruction inst = decode_i_type(instruction);
@ -528,32 +412,32 @@ static void execute_system(Hart* hart, uint32_t instruction)
}
break;
}
case 1: // CRSRW
case 1: // CSRRW
{
uint16_t crs_id = inst.imm & 0xFFF;
uint16_t csr_id = inst.imm & 0xFFF;
if (inst.rd == 0)
{
crs_write(hart, crs_id, hart->regs[inst.rs1]);
csr_action(hart, csr_id, hart->regs[inst.rs1], CSR_W);
}
else
{
hart->regs[inst.rd] = crs_read_write(hart, crs_id, hart->regs[inst.rs1]);
hart->regs[inst.rd] = csr_action(hart, csr_id, hart->regs[inst.rs1], CSR_RW);
}
break;
}
case 2: // CRSRS
case 2: // CSRRS
{
uint16_t crs_id = inst.imm & 0xFFF;
uint16_t csr_id = inst.imm & 0xFFF;
uint32_t value = 0;
if (inst.rs1 == 0)
{
value = crs_read(hart, crs_id);
value = csr_action(hart, csr_id, 0, CSR_R);
}
else
{
value = crs_read_set(hart, crs_id, hart->regs[inst.rs1]);
value = csr_action(hart, csr_id, hart->regs[inst.rs1], CSR_RS);
}
if (inst.rd != 0)
@ -562,18 +446,18 @@ static void execute_system(Hart* hart, uint32_t instruction)
}
break;
}
case 3: // CRSRC
case 3: // CSRRC
{
uint16_t crs_id = inst.imm & 0xFFF;
uint16_t csr_id = inst.imm & 0xFFF;
uint32_t value = 0;
if (inst.rs1 == 0)
{
value = crs_read(hart, crs_id);
value = csr_action(hart, csr_id, 0, CSR_R);
}
else
{
value = crs_read_clear(hart, crs_id, hart->regs[inst.rs1]);
value = csr_action(hart, csr_id, hart->regs[inst.rs1], CSR_RC);
}
if (inst.rd != 0)
@ -582,32 +466,32 @@ static void execute_system(Hart* hart, uint32_t instruction)
}
break;
}
case 5: // CRSRWI
case 5: // CSRRWI
{
uint16_t crs_id = inst.imm & 0xFFF;
uint16_t csr_id = inst.imm & 0xFFF;
if (inst.rd == 0)
{
crs_write(hart, crs_id, inst.rs1);
csr_action(hart, csr_id, inst.rs1, CSR_W);
}
else
{
hart->regs[inst.rd] = crs_read_write(hart, crs_id, inst.rs1);
hart->regs[inst.rd] = csr_action(hart, csr_id, inst.rs1, CSR_RW);
}
break;
}
case 6: // CRSRSI
case 6: // CSRRSI
{
uint16_t crs_id = inst.imm & 0xFFF;
uint16_t csr_id = inst.imm & 0xFFF;
uint32_t value = 0;
if (inst.rs1 == 0)
{
value = crs_read(hart, crs_id);
value = csr_action(hart, csr_id, 0, CSR_R);
}
else
{
value = crs_read_set(hart, crs_id, inst.rs1);
value = csr_action(hart, csr_id, inst.rs1, CSR_RS);
}
if (inst.rd != 0)
@ -616,18 +500,18 @@ static void execute_system(Hart* hart, uint32_t instruction)
}
break;
}
case 7: // CRSRCI
case 7: // CSRRCI
{
uint16_t crs_id = inst.imm & 0xFFF;
uint16_t csr_id = inst.imm & 0xFFF;
uint32_t value = 0;
if (inst.rs1 == 0)
{
value = crs_read(hart, crs_id);
value = csr_action(hart, csr_id, 0, CSR_R);
}
else
{
value = crs_read_clear(hart, crs_id, inst.rs1);
value = csr_action(hart, csr_id, inst.rs1, CSR_RC);
}
if (inst.rd != 0)
@ -644,6 +528,10 @@ static void execute_system(Hart* hart, uint32_t instruction)
void execute(Hart* hart, uint32_t instruction)
{
// @Todo Better time (same on all cores)
// @Todo Memory-map mtime and mtimecmp
hart->time = __rdtsc();
switch (instruction & 0x7f)
{
case 0x03:
@ -721,16 +609,30 @@ void execute(Hart* hart, uint32_t instruction)
}
assert(hart->regs[0] == 0);
hart->instret += 1;
}
void execute_from(Hart* hart, uint32_t start_address)
{
hart->pc = start_address;
hart->halted = false;
while (!hart->halted)
while (true)
{
uint32_t instruction = load_word(hart, hart->pc);
execute(hart, instruction);
}
}
void csr_init(Hart* hart);
void hart_init(Hart* hart, uint32_t id, char* mem, uint32_t mem_size)
{
memset(hart, 0, sizeof(Hart));
hart->hartid = id;
hart->priv = PRIV_M;
hart->mem = mem;
hart->mem_size = mem_size;
csr_init(hart);
}