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System call emulation related codes are separated.
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@moizumi99
moizumi99 committed Feb 2, 2020
1 parent 5af68da commit a33fe2d
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Showing 4 changed files with 259 additions and 224 deletions.
4 changes: 2 additions & 2 deletions CMakeLists.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -34,7 +34,7 @@ add_executable(cpu_test
cpu_test.cc
RISCV_cpu.cc
RISCV_cpu.h
memory_wrapper.cpp memory_wrapper.h)
memory_wrapper.cpp memory_wrapper.h system_call_emulator.cpp system_call_emulator.h)

add_executable(RISCV_Emulator
assembler.cc
Expand All @@ -49,7 +49,7 @@ add_executable(RISCV_Emulator
RISCV_cpu.h
RISCV_Emulator.cc
RISCV_Emulator.h
memory_wrapper.cpp memory_wrapper.h)
memory_wrapper.cpp memory_wrapper.h system_call_emulator.cpp system_call_emulator.h)

add_executable(memory_wrapper_test
memory_wrapper.cpp
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224 changes: 2 additions & 222 deletions RISCV_cpu.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -2,36 +2,10 @@
#include "bit_tools.h"
#include "instruction_encdec.h"
#include "memory_wrapper.h"
#include "system_call_emulator.h"
#include <iostream>
#include <tuple>
#include <unistd.h>
#include <stdint.h>
#include <sys/stat.h>
#include <fcntl.h>

struct riscv32_newlib_stat {
uint16_t st_dev; // 0
uint16_t st_ino; // 2
uint32_t st_mode; // 4
uint16_t st_nlink; // 8
uint16_t st_uid; // 10
uint16_t st_gid; // 12
uint16_t st_rdev; // 14
int32_t st_size; // 16
int32_t st_spare0; // 20
int64_t st_atim; // 24
int32_t st_spare1; // 32
int32_t st_spare1_2; // 36
int64_t st_mtim; // 40
int32_t st_spare2; // 48
int32_t st_spare2_2; // 52
int64_t st_ctim; // 56
int32_t st_spare3; // 60
int32_t st_blksize; // 68
int32_t st_blocks; // 72
int32_t st_spare4[2]; // 76
};


RiscvCpu::RiscvCpu() {
for (int i = 0; i < kRegNum; i++) {
Expand Down Expand Up @@ -72,204 +46,10 @@ void RiscvCpu::set_work_memory(uint32_t top, uint32_t bottom) {
* riscv-gnu-toolchain/linux-headers/include/asm-generic/unistd.h
*/

void show_guest_stat(const riscv32_newlib_stat &guest_stat) {
std::cerr << "st_dev: " << guest_stat.st_dev << std::endl;
std::cerr << "st_ino: " << guest_stat.st_ino << std::endl;
std::cerr << "st_mode: " << guest_stat.st_mode << std::endl;
std::cerr << "st_nlink: " << guest_stat.st_nlink << std::endl;
std::cerr << "st_uid: " << guest_stat.st_uid << std::endl;
std::cerr << "st_gid: " << guest_stat.st_gid << std::endl;
std::cerr << "st_rdev: " << guest_stat.st_rdev << std::endl;
std::cerr << "st_size: " << guest_stat.st_size << std::endl;
std::cerr << "st_atime: " << guest_stat.st_atim << std::endl;
std::cerr << "st_mtime: " << guest_stat.st_mtim << std::endl;
std::cerr << "st_ctime: " << guest_stat.st_ctim << std::endl;
std::cerr << "st_blksize: " << guest_stat.st_blksize << std::endl;
std::cerr << "st_blocks: " << guest_stat.st_blocks << std::endl;
}

void show_host_stat(const struct stat &host_stat) {
std::cerr << "st_dev: " << host_stat.st_dev << std::endl;
std::cerr << "st_ino: " << host_stat.st_ino << std::endl;
std::cerr << "st_mode: " << host_stat.st_mode << std::endl;
std::cerr << "st_nlink: " << host_stat.st_nlink << std::endl;
std::cerr << "st_uid: " << host_stat.st_uid << std::endl;
std::cerr << "st_gid: " << host_stat.st_gid << std::endl;
std::cerr << "st_rdev: " << host_stat.st_rdev << std::endl;
std::cerr << "st_size: " << host_stat.st_size << std::endl;
std::cerr << "st_blksize: " << host_stat.st_blksize << std::endl;
std::cerr << "st_blocks: " << host_stat.st_blocks << std::endl;
std::cerr << "st_atim.tv_sec: " << host_stat.st_atim.tv_sec << std::endl;
std::cerr << "st_atim.tv_nsec: " << host_stat.st_atim.tv_nsec << std::endl;
std::cerr << "st_mtim.tv_sec: " << host_stat.st_mtim.tv_sec << std::endl;
std::cerr << "st_mtim.tv_nsec: " << host_stat.st_mtim.tv_nsec << std::endl;
std::cerr << "st_ctim.tv_sec: " << host_stat.st_ctim.tv_sec << std::endl;
std::cerr << "st_ctim.tv_nsec: " << host_stat.st_ctim.tv_nsec << std::endl;
}

void conv_guest_stat_to_host_stat(const riscv32_newlib_stat &guest_stat, struct stat *host_stat) {
host_stat->st_dev = guest_stat.st_dev;
host_stat->st_ino = guest_stat.st_ino;
host_stat->st_mode = guest_stat.st_mode;
host_stat->st_nlink = guest_stat.st_nlink;
host_stat->st_uid = guest_stat.st_uid;
host_stat->st_gid = guest_stat.st_gid;
host_stat->st_rdev = guest_stat.st_rdev;
host_stat->st_size = guest_stat.st_size;
host_stat->st_blksize = guest_stat.st_blksize;
host_stat->st_blocks = guest_stat.st_blocks;
host_stat->st_atim.tv_sec = guest_stat.st_atim;
host_stat->st_atim.tv_nsec = 0;
host_stat->st_mtim.tv_sec = guest_stat.st_mtim ;
host_stat->st_mtim.tv_nsec = 0;
host_stat->st_ctim.tv_sec = guest_stat.st_ctim;
host_stat->st_ctim.tv_nsec = 0;
}

void conv_host_stat_to_guest_stat(const struct stat &host_stat, riscv32_newlib_stat *guest_stat) {
guest_stat->st_dev = host_stat.st_dev;
guest_stat->st_ino = host_stat.st_ino;
guest_stat->st_mode = host_stat.st_mode;
guest_stat->st_nlink = host_stat.st_nlink;
guest_stat->st_uid = host_stat.st_uid;
guest_stat->st_gid = host_stat.st_gid;
guest_stat->st_rdev = host_stat.st_rdev;
guest_stat->st_size = host_stat.st_size;
guest_stat->st_blksize = host_stat.st_blksize;
guest_stat->st_blocks = host_stat.st_blocks;
guest_stat->st_atim = (int64_t) host_stat.st_atim.tv_sec;
guest_stat->st_mtim = (int64_t) host_stat.st_mtim.tv_sec;
guest_stat->st_ctim = (int64_t) host_stat.st_ctim.tv_sec;
}

size_t memory_wrapper_strlen(const memory_wrapper &mem, size_t address, size_t max = 256) {
size_t counter = 0;
size_t index = address;
while(mem[index++] && counter < max) {
++counter;
}
return counter;
}

char *memory_wrapper_copy(const memory_wrapper &mem, size_t address, size_t length, char *dst) {
for (size_t i = 0; i < length; ++i) {
dst[i] = mem[address + i];
}
return dst;
}

std::pair<bool, bool> RiscvCpu::system_call() {
auto &mem = *memory;
bool end_flag = false;
bool error_flag = false;
if (reg[A7] == 93) {
// Exit system call.
std::cerr << "Exit System Call" << std::endl;
end_flag = true;
} else if (reg[A7] == 64) {
// Write.
std::cerr << "Write System Call" << std::endl;
std::cerr << "FD = " << reg[A0] << std::endl;
int length = reg[A2];
unsigned char *buffer = new unsigned char[length];
for (int i = 0; i < length; i++) {
buffer[i] = mem[reg[A1] + i];
}
size_t return_value = write(reg[A0], buffer, length);
// // Ignore fd. Always output to stdout.
// for (int i = 0; i < length; i++) {
// putchar(mem[reg[A1] + i]);
// }
reg[A0] = (uint32_t) return_value;
delete buffer;
} else if (reg[A7] == 214) {
// BRK
std::cerr << "BRK System Call" << std::endl;
if (reg[A0] == 0) {
reg[A0] = brk;
} else if (reg[A0] < top) {
brk = reg[A0];
// reg[A0] = 0;
} else {
reg[A0] = -1;
}
} else if (reg[A7] == 63) {
// READ
std::cerr << "Read System Call" << std::endl;
int length = reg[A2];
unsigned char *buffer = new unsigned char[length];
size_t return_value = read(reg[A0], buffer, length);
reg[A0] = (uint32_t) return_value;
for (int i = 0; i < length; i++) {
mem[reg[A1] + i] = buffer[i];
}
delete buffer;
} else if (reg[A7] == 80) {
// fstat
std::cerr << "Fstat System Call" << std::endl;
std::cerr << "fd: " << reg[A0] << std::endl;
struct riscv32_newlib_stat guest_stat;
std::cerr << "riscv32_stat size: " << sizeof(struct riscv32_newlib_stat) << std::endl;
std::cerr << "&st_atime: " <<
(int) (((char *) (&guest_stat.st_atim)) - ((char *) (&guest_stat))) << std::endl;
std::cerr << "&st_mtime: " <<
(int) (((char *) (&guest_stat.st_mtim)) - ((char *) (&guest_stat))) << std::endl;
std::cerr << "&st_blksize: " <<
(int) (((char *) (&guest_stat.st_blksize)) - ((char *) (&guest_stat))) << std::endl;
std::cerr << "&st_spare4[0]: " <<
(int) (((char *) (&guest_stat.st_spare4[0])) - ((char *) (&guest_stat))) << std::endl;
unsigned char *statbuf_p = (unsigned char *) &guest_stat;
for (int i = 0; i < sizeof(struct riscv32_newlib_stat); i++) {
statbuf_p[i] = mem[reg[A1] + i];
}
std::cerr << "Guest: struct stat (initial)" << std::endl;
show_guest_stat(guest_stat);

struct stat host_stat;
conv_guest_stat_to_host_stat(guest_stat, &host_stat);
int return_value = fstat(reg[A0], &host_stat);
// std::cerr << "Host: struct stat\n";
// show_host_stat(host_stat);

conv_host_stat_to_guest_stat(host_stat, &guest_stat);
std::cerr << "ret: " << reg[A0] << std::endl;
std::cerr << "Guest: struct stat\n";
show_guest_stat(guest_stat);
for (int i = 0; i < sizeof(riscv32_newlib_stat); i++) {
(*memory)[reg[A1] + i] = statbuf_p[i];
}
reg[A0] = return_value;
} else if (reg[A7] == 57) {
// Close.
std::cerr << "Close System Call" << std::endl;
int return_value = close(reg[A0]);
reg[A0] = return_value;
} else if (reg[A7] == 1024) {
// Open
std::cerr << "Open System Call" << std::endl;
constexpr size_t kMax = 1024;
size_t length = memory_wrapper_strlen(*memory, reg[A0], kMax);
int return_value = -1;
if (length > 0) {
char *buffer = new char[length + 1];
memory_wrapper_copy(*memory, reg[A0], length, buffer);
buffer[length] = 0;
std::cerr << "FIle path: " << buffer << std::endl;
return_value = open(buffer, reg[A1], reg[A2]);
delete buffer;
}
reg[A0] = return_value;
} else if (reg[A7] == 62){
// lseek
std::cerr << "Lseek System Call" << std::endl;
int return_value = lseek(reg[A0], reg[A1], reg[A2]);
reg[A0] = return_value;
} else {
std::cerr << "Undefined system call (" << reg[A7] << ")\n";
reg[A0] = 0;
}

return std::make_pair(error_flag, end_flag);
return system_call_emulation(memory, reg, top, &brk);
}

uint32_t RiscvCpu::load_wd(uint32_t address) {
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