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//
// Project: CMiniLang
// Author: bajdcc
//
#include <cassert>
#include <memory.h>
#include <cstring>
#include "cvm.h"
#include "cgen.h"
int g_argc;
char **g_argv;
namespace clib {
#define INC_PTR 4
#define VMM_ARG(s, p) ((s) + p * INC_PTR)
#define VMM_ARGS(t, n) vmm_get(t - (n) * INC_PTR)
uint32_t cvm::pmm_alloc() {
auto page = PAGE_ALIGN_UP((uint32_t) memory.alloc_array<byte>(PAGE_SIZE * 2));
memset((void *) page, 0, PAGE_SIZE);
return page;
}
void cvm::vmm_init() {
pgd_kern = (pde_t *) malloc(PTE_SIZE * sizeof(pde_t));
memset(pgd_kern, 0, PTE_SIZE * sizeof(pde_t));
pte_kern = (pte_t *) malloc(PTE_COUNT * PTE_SIZE * sizeof(pte_t));
memset(pte_kern, 0, PTE_COUNT * PTE_SIZE * sizeof(pte_t));
pgdir = pgd_kern;
uint32_t i;
// map 4G memory, physcial address = virtual address
for (i = 0; i < PTE_SIZE; i++) {
pgd_kern[i] = (uint32_t) pte_kern[i] | PTE_P | PTE_R | PTE_K;
}
uint32_t *pte = (uint32_t *) pte_kern;
for (i = 1; i < PTE_COUNT * PTE_SIZE; i++) {
pte[i] = (i << 12) | PTE_P | PTE_R | PTE_K; // i是页表号
}
}
// 虚页映射
// va = 虚拟地址 pa = 物理地址
void cvm::vmm_map(uint32_t va, uint32_t pa, uint32_t flags) {
uint32_t pde_idx = PDE_INDEX(va); // 页目录号
uint32_t pte_idx = PTE_INDEX(va); // 页表号
pte_t *pte = (pte_t *) (pgdir[pde_idx] & PAGE_MASK); // 页表
if (!pte) { // 缺页
if (va >= USER_BASE) { // 若是用户地址则转换
pte = (pte_t *) pmm_alloc(); // 申请物理页框，用作新页表
pgdir[pde_idx] = (uint32_t) pte | PTE_P | flags; // 设置页表
pte[pte_idx] = (pa & PAGE_MASK) | PTE_P | flags; // 设置页表项
} else { // 内核地址不转换
pte = (pte_t *) (pgd_kern[pde_idx] & PAGE_MASK); // 取得内核页表
pgdir[pde_idx] = (uint32_t) pte | PTE_P | flags; // 设置页表
}
} else { // pte存在
pte[pte_idx] = (pa & PAGE_MASK) | PTE_P | flags; // 设置页表项
}
#if 0
printf("MEMMAP> V=%08X P=%08X\n", va, pa);
#endif
}
// 释放虚页
void cvm::vmm_unmap(pde_t *pde, uint32_t va) {
uint32_t pde_idx = PDE_INDEX(va);
uint32_t pte_idx = PTE_INDEX(va);
pte_t *pte = (pte_t *) (pde[pde_idx] & PAGE_MASK);
if (!pte) {
return;
}
pte[pte_idx] = 0; // 清空页表项，此时有效位为零
}
// 是否已分页
int cvm::vmm_ismap(uint32_t va, uint32_t *pa) const {
uint32_t pde_idx = PDE_INDEX(va);
uint32_t pte_idx = PTE_INDEX(va);
pte_t *pte = (pte_t *) (pgdir[pde_idx] & PAGE_MASK);
if (!pte) {
return 0; // 页表不存在
}
if (pte[pte_idx] != 0 && (pte[pte_idx] & PTE_P) && pa) {
*pa = pte[pte_idx] & PAGE_MASK; // 计算物理页面
return 1; // 页面存在
}
return 0; // 页表项不存在
}
char *cvm::vmm_getstr(uint32_t va) {
uint32_t pa;
if (vmm_ismap(va, &pa)) {
return (char *) pa + OFFSET_INDEX(va);
}
vmm_map(va, pmm_alloc(), PTE_U | PTE_P | PTE_R);
#if 0
printf("VMMSTR> Invalid VA: %08X\n", va);
#endif
assert(0);
return vmm_getstr(va);
}
template<class T>
T cvm::vmm_get(uint32_t va) {
uint32_t pa;
if (vmm_ismap(va, &pa)) {
return *(T *) ((byte *) pa + OFFSET_INDEX(va));
}
vmm_map(va, pmm_alloc(), PTE_U | PTE_P | PTE_R);
#if 1
printf("VMMGET> Invalid VA: %08X\n", va);
#endif
throw std::exception();
return vmm_get<T>(va);
}
template<class T>
T cvm::vmm_set(uint32_t va, T value) {
uint32_t pa;
if (vmm_ismap(va, &pa)) {
*(T *) ((byte *) pa + OFFSET_INDEX(va)) = value;
return value;
}
vmm_map(va, pmm_alloc(), PTE_U | PTE_P | PTE_R);
#if 0
printf("VMMSET> Invalid VA: %08X\n", va);
#endif
throw std::exception();
return vmm_set(va, value);
}
void cvm::vmm_setstr(uint32_t va, const char *value) {
auto len = strlen(value);
for (uint32_t i = 0; i < len; i++) {
vmm_set(va + i, value[i]);
}
vmm_set(va + len, '\0');
}
uint32_t vmm_pa2va(uint32_t base, uint32_t size, uint32_t pa) {
return base + (pa & (SEGMENT_MASK));
}
uint32_t cvm::vmm_malloc(uint32_t size) {
#if 0
printf("MALLOC> Available: %08X\n", heap.available() * 0x10);
#endif
auto ptr = heap.alloc_array<byte>(size);
if (ptr == nullptr) {
printf("out of memory");
exit(-1);
}
if (ptr < heapHead) {
heap.alloc_array<byte>(heapHead - ptr);
#if 0
printf("MALLOC> Skip %08X bytes\n", heapHead - ptr);
#endif
return vmm_malloc(size);
}
if (ptr + size >= heapHead + HEAP_SIZE * PAGE_SIZE) {
printf("out of memory");
exit(-1);
}
auto va = vmm_pa2va(HEAP_BASE, HEAP_SIZE, ((uint32_t) ptr - (uint32_t) heapHead));
#if 0
printf("MALLOC> V=%08X P=%p> %08X bytes\n", va, ptr, size);
#endif
return va;
}
uint32_t cvm::vmm_memset(uint32_t va, uint32_t value, uint32_t count) {
#if 0
uint32_t pa;
if (vmm_ismap(va, &pa))
{
pa |= OFFSET_INDEX(va);
printf("MEMSET> V=%08X P=%08X S=%08X\n", va, pa, count);
}
else
{
printf("MEMSET> V=%08X P=ERROR S=%08X\n", va, count);
}
#endif
for (uint32_t i = 0; i < count; i++) {
#if 0
printf("MEMSET> V=%08X\n", va + i);
#endif
vmm_set<byte>(va + i, value);
}
return 0;
}
uint32_t cvm::vmm_memcmp(uint32_t src, uint32_t dst, uint32_t count) {
for (uint32_t i = 0; i < count; i++) {
#if 0
printf("MEMCMP> '%c':'%c'\n", vmm_get<byte>(src + i), vmm_get<byte>(dst + i));
#endif
if (vmm_get<byte>(src + i) > vmm_get<byte>(dst + i))
return 1;
if (vmm_get<byte>(src + i) < vmm_get<byte>(dst + i))
return -1;
}
return 0;
}
template<class T>
void cvm::vmm_pushstack(uint32_t &sp, T value) {
sp -= sizeof(T);
vmm_set(sp, value);
}
template<class T>
T cvm::vmm_popstack(uint32_t &sp) {
T t = vmm_get(sp);
sp += sizeof(T);
return t;
}
//-----------------------------------------
cvm::cvm(const std::vector<LEX_T(int)> &text, const std::vector<LEX_T(char)> &data) {
vmm_init();
uint32_t pa;
/* 映射4KB的代码空间 */
{
auto size = PAGE_SIZE / sizeof(int);
for (uint32_t i = 0, start = 0; start < text.size(); ++i, start += size) {
vmm_map(USER_BASE + PAGE_SIZE * i, (uint32_t) pmm_alloc(), PTE_U | PTE_P | PTE_R); // 用户代码空间
if (vmm_ismap(USER_BASE + PAGE_SIZE * i, &pa)) {
auto s = start + size > text.size() ? (text.size() & (size - 1)) : size;
for (uint32_t j = 0; j < s; ++j) {
*((uint32_t *) pa + j) = (uint) text[start + j];
#if 0
printf("[%p]> [%08X] %08X\n", (int*)pa + j, USER_BASE + PAGE_SIZE * i + j * 4, vmm_get<uint32_t>(USER_BASE + PAGE_SIZE * i + j * 4));
#endif
}
}
}
}
/* 映射4KB的数据空间 */
{
auto size = PAGE_SIZE;
for (uint32_t i = 0, start = 0; start < data.size(); ++i, start += size) {
vmm_map(DATA_BASE + PAGE_SIZE * i, (uint32_t) pmm_alloc(), PTE_U | PTE_P | PTE_R); // 用户数据空间
if (vmm_ismap(DATA_BASE + PAGE_SIZE * i, &pa)) {
auto s = start + size > data.size() ? ((sint) data.size() & (size - 1)) : size;
for (uint32_t j = 0; j < s; ++j) {
*((char *) pa + j) = data[start + j];
#if 0
printf("[%p]> [%08X] %d\n", (char*)pa + j, DATA_BASE + PAGE_SIZE * i + j, vmm_get<byte>(DATA_BASE + PAGE_SIZE * i + j));
#endif
}
}
}
}
/* 映射4KB的栈空间 */
vmm_map(STACK_BASE, (uint32_t) pmm_alloc(), PTE_U | PTE_P | PTE_R); // 用户栈空间
/* 映射16KB的堆空间 */
{
auto head = heap.alloc_array<byte>(PAGE_SIZE * (HEAP_SIZE + 2));
#if 0
printf("HEAP> ALLOC=%p\n", head);
#endif
heapHead = head; // 得到内存池起始地址
heap.free_array(heapHead);
heapHead = (byte *) PAGE_ALIGN_UP((uint32_t) head);
#if 0
printf("HEAP> HEAD=%p\n", heapHead);
#endif
memset(heapHead, 0, PAGE_SIZE * HEAP_SIZE);
for (int i = 0; i < HEAP_SIZE; ++i) {
vmm_map(HEAP_BASE + PAGE_SIZE * i, (uint32_t) heapHead + PAGE_SIZE * i, PTE_U | PTE_P | PTE_R);
}
}
}
cvm::~cvm() {
free(pgd_kern);
free(pte_kern);
}
void cvm::init_args(uint32_t *args, uint32_t sp, uint32_t pc, bool converted /*= false*/) {
auto num = vmm_get(pc + INC_PTR); /* 利用之后的ADJ清栈指令知道函数调用的参数个数 */
auto tmp = VMM_ARG(sp, num);
for (int k = 0; k < num; k++) {
auto arg = VMM_ARGS(tmp, k + 1);
if (converted && (arg & DATA_BASE))
args[k] = (uint32_t) vmm_getstr(arg);
else
args[k] = (uint32_t) arg;
}
}
int cvm::exec(int entry) {
auto poolsize = PAGE_SIZE;
auto stack = STACK_BASE;
auto data = DATA_BASE;
auto base = USER_BASE;
auto sp = stack + poolsize; // 4KB / sizeof(int) = 1024
{
auto argvs = vmm_malloc(g_argc * INC_PTR);
for (auto i = 0; i < g_argc; i++) {
auto str = vmm_malloc(256);
vmm_setstr(str, g_argv[i]);
vmm_set(argvs + INC_PTR * i, str);
}
vmm_pushstack(sp, EXIT);
vmm_pushstack(sp, PUSH);
auto tmp = sp;
vmm_pushstack(sp, g_argc);
vmm_pushstack(sp, argvs);
vmm_pushstack(sp, tmp);
}
auto pc = USER_BASE + entry * INC_PTR;
auto ax = 0;
auto bp = 0;
auto log = false;
#if 0
if (log) {
printf("\n---------------- STACK BEGIN <<<< \n");
printf("AX: %08X BP: %08X SP: %08X\n", ax, bp, sp);
for (uint32_t i = sp; i < STACK_BASE + PAGE_SIZE; i += 4) {
printf("[%08X]> %08X\n", i, vmm_get<uint32_t>(i));
}
printf("---------------- STACK END >>>>\n\n");
}
#endif
auto cycle = 0;
uint32_t args[6];
while (true) {
cycle++;
auto op = vmm_get(pc); // get next operation code
pc += INC_PTR;
#if 0
assert(op <= EXIT);
// print debug info
if (true) {
printf("%04d> [%08X] %02d %.4s", cycle, pc, op,
&"NOP, LEA ,IMM ,IMX ,JMP ,CALL,JZ ,JNZ ,ENT ,ADJ ,LEV ,LI ,SI ,LC ,SC ,PUSH,LOAD,"
"OR ,XOR ,AND ,EQ ,NE ,LT ,GT ,LE ,GE ,SHL ,SHR ,ADD ,SUB ,MUL ,DIV ,MOD ,"
"OPEN,READ,CLOS,PRTF,MALC,MSET,MCMP,TRAC,TRAN,EXIT"[op * 5]);
if (op == PUSH)
printf(" %08X\n", (uint32_t) ax);
else if (op <= ADJ)
printf(" %d\n", vmm_get(pc));
else
printf("\n");
}
#endif
switch (op) {
case IMM: {
ax = vmm_get(pc);
pc += INC_PTR;
} /* load immediate value to ax */
break;
case LI: {
ax = vmm_get(ax);
} /* load integer to ax, address in ax */
break;
case SI: {
vmm_set(vmm_popstack(sp), ax);
} /* save integer to address, value in ax, address on stack */
break;
case LC: {
ax = vmm_get<byte>(ax);
} /* load integer to ax, address in ax */
break;
case SC: {
vmm_set<byte>(vmm_popstack(sp), ax & 0xff);
} /* save integer to address, value in ax, address on stack */
break;
case LOAD: {
ax = data | ((ax) & (PAGE_SIZE - 1));
} /* load the value of ax, segment = DATA_BASE */
break;
case PUSH: {
vmm_pushstack(sp, ax);
} /* push the value of ax onto the stack */
break;
case JMP: {
pc = base + vmm_get(pc) * INC_PTR;
} /* jump to the address */
break;
case JZ: {
pc = ax ? pc + INC_PTR : (base + vmm_get(pc) * INC_PTR);
} /* jump if ax is zero */
break;
case JNZ: {
pc = ax ? (base + vmm_get(pc) * INC_PTR) : pc + INC_PTR;
} /* jump if ax is zero */
break;
case CALL: {
vmm_pushstack(sp, pc + INC_PTR);
pc = base + vmm_get(pc) * INC_PTR;
#if 0
printf("CALL> PC=%08X\n", pc);
#endif
} /* call subroutine */
/* break;case RET: {pc = (int *)*sp++;} // return from subroutine; */
break;
case ENT: {
vmm_pushstack(sp, bp);
bp = sp;
sp = sp - vmm_get(pc);
pc += INC_PTR;
} /* make new stack frame */
break;
case ADJ: {
sp = sp + vmm_get(pc) * INC_PTR;
pc += INC_PTR;
} /* add esp, <size> */
break;
case LEV: {
sp = bp;
bp = vmm_popstack(sp);
pc = vmm_popstack(sp);
#if 0
printf("RETURN> PC=%08X\n", pc);
#endif
} /* restore call frame and PC */
break;
case LEA: {
ax = bp + vmm_get(pc);
pc += INC_PTR;
} /* load address for arguments. */
break;
case OR:
ax = vmm_popstack(sp) | ax;
break;
case XOR:
ax = vmm_popstack(sp) ^ ax;
break;
case AND:
ax = vmm_popstack(sp) & ax;
break;
case EQ:
ax = vmm_popstack(sp) == ax;
break;
case NE:
ax = vmm_popstack(sp) != ax;
break;
case LT:
ax = vmm_popstack(sp) < ax;
break;
case LE:
ax = vmm_popstack(sp) <= ax;
break;
case GT:
ax = vmm_popstack(sp) > ax;
break;
case GE:
ax = vmm_popstack(sp) >= ax;
break;
case SHL:
ax = vmm_popstack(sp) << ax;
break;
case SHR:
ax = vmm_popstack(sp) >> ax;
break;
case ADD:
ax = vmm_popstack(sp) + ax;
break;
case SUB:
ax = vmm_popstack(sp) - ax;
break;
case MUL:
ax = vmm_popstack(sp) * ax;
break;
case DIV:
ax = vmm_popstack(sp) / ax;
break;
case MOD:
ax = vmm_popstack(sp) % ax;
break;
// --------------------------------------
case PRTF: {
init_args(args, sp, pc);
ax = printf(vmm_getstr(args[0]), args[1], args[2], args[3], args[4], args[5]);
}
break;
case EXIT: {
printf("exit(%d)\n", ax);
return ax;
}
break;
case OPEN: {
init_args(args, sp, pc);
ax = (int) fopen(vmm_getstr(args[0]), "rb");
#if 0
printf("OPEN> name=%s fd=%08X\n", vmm_getstr(args[0]), ax);
#endif
}
break;
case READ: {
init_args(args, sp, pc);
#if 0
printf("READ> src=%p size=%08X fd=%08X\n", vmm_getstr(args[1]), args[2], args[0]);
#endif
ax = (int) fread(vmm_getstr(args[1]), 1, (size_t) args[2], (FILE *) args[0]);
if (ax > 0) {
rewind((FILE *) args[0]); // 坑：避免重复读取
ax = (int) fread(vmm_getstr(args[1]), 1, (size_t) ax, (FILE *) args[0]);
vmm_getstr(args[1])[ax] = 0;
#if 0
printf("READ> %s\n", vmm_getstr(args[1]));
#endif
}
}
break;
case CLOS: {
init_args(args, sp, pc);
ax = (int) fclose((FILE *) args[0]);
}
break;
case MALC: {
init_args(args, sp, pc);
ax = (int) vmm_malloc((uint32_t) args[0]);
}
break;
case MSET: {
init_args(args, sp, pc);
#if 0
printf("MEMSET> PTR=%08X SIZE=%08X VAL=%d\n", (uint32_t)vmm_getstr(args[0]), (uint32_t)args[2], (uint32_t)args[1]);
#endif
ax = (int) vmm_memset(args[0], (uint32_t) args[1], (uint32_t) args[2]);
}
break;
case MCMP: {
init_args(args, sp, pc);
ax = (int) vmm_memcmp(args[0], args[1], (uint32_t) args[2]);
}
break;
case TRAC: {
init_args(args, sp, pc);
ax = log;
log = args[0] != 0;
}
break;
case TRAN: {
init_args(args, sp, pc);
ax = (uint32_t) vmm_getstr(args[0]);
}
break;
default: {
printf("AX: %08X BP: %08X SP: %08X PC: %08X\n", ax, bp, sp, pc);
for (uint32_t i = sp; i < STACK_BASE + PAGE_SIZE; i += 4) {
printf("[%08X]> %08X\n", i, vmm_get<uint32_t>(i));
}
printf("unknown instruction:%d\n", op);
throw std::exception();
exit(-1);
}
}
#if 1
if (log) {
printf("\n---------------- STACK BEGIN <<<< \n");
printf("AX: %08X BP: %08X SP: %08X PC: %08X\n", ax, bp, sp, pc);
for (uint32_t i = sp; i < STACK_BASE + PAGE_SIZE; i += 4) {
printf("[%08X]> %08X\n", i, vmm_get<uint32_t>(i));
}
printf("---------------- STACK END >>>>\n\n");
}
#endif
}
return 0;
}
}