eVM/operations.c at master · NDStrahilevitz/eVM · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
#include <stdlib.h>

#include "operations.h"
#include "exitcodes.h"

#define STACK_END 0x1fff

void vm_end(vm_t* vm){
    vm->running = 0;
}

void vm_nop(vm_t* vm){
    ++vm->memory[PC];
}

void vm_push(vm_t* vm, const uint32_t val){
    uint32_t sp_loc = vm->registers[SP]++;
    if(sp_loc > STACK_END){
        exit(SEGMENTATION_FAULT);
    }
    vm->memory[sp_loc] = val;
}

void vm_pop(vm_t* vm, const REGISTER dest){
    uint32_t sp_loc = vm->registers[SP]--;
    if(sp_loc == 0)
        exit(SEGMENTATION_FAULT);
    uint32_t val = vm->memory[sp_loc - 1];
    vm->memory[sp_loc - 1] = 0;
    vm->registers[dest] = val;
}

void vm_mov(vm_t* vm, const REGISTER dest, const uint32_t arg){
    vm->registers[dest] = arg;
}

void vm_ldr(vm_t* vm, const REGISTER dest, const REGISTER ptr_reg){
    vm->registers[dest] = vm->memory[vm->registers[ptr_reg]];
}

void vm_str(vm_t* vm, const REGISTER ptr_reg, const REGISTER val_reg){
    vm->memory[vm->registers[ptr_reg]] = vm->registers[val_reg];
}

void vm_add(vm_t* vm, const REGISTER dest, const uint32_t arg){
    uint32_t prevVal = vm->registers[dest];
    uint32_t res = vm->registers[dest] += arg;
    if(res >> 31)
        vm_set_flag(vm, NF);
    else
        vm_clear_flag(vm, NF);
    if(res < prevVal)
        vm_set_flag(vm, CF);
    else
        vm_clear_flag(vm, CF);
    if(prevVal >> 31  == arg >> 31 && res >> 31 != prevVal >> 31)
        vm_set_flag(vm, OF);
    else
        vm_clear_flag(vm, OF);
    if(res == 0)
        vm_set_flag(vm, ZF);
    else
        vm_clear_flag(vm, ZF);
}

void vm_sub(vm_t* vm, const REGISTER dest, const uint32_t arg){
    uint32_t prevVal = vm->registers[dest];
    uint32_t res = vm->registers[dest] -= arg;
    if(res >> 31)
        vm_set_flag(vm, NF);
    else
        vm_clear_flag(vm, NF);
    if(arg > prevVal)
        vm_set_flag(vm, CF);
    else
        vm_clear_flag(vm, CF);
    if(prevVal >> 31  != arg >> 31 && arg >> 31 == res >> 31)
        vm_set_flag(vm, OF);
    else
        vm_clear_flag(vm, OF);
    if(res == 0)
        vm_set_flag(vm, ZF);
    else
        vm_clear_flag(vm, ZF);
}

void vm_mul(vm_t* vm, const REGISTER dest, const uint32_t arg){
    exit(NOT_YET_IMPLEMENTED);
}

void vm_imul(vm_t* vm, const REGISTER dest, const uint32_t arg){
    exit(NOT_YET_IMPLEMENTED);
}

void vm_div(vm_t* vm, const REGISTER dest, const uint32_t arg){
    exit(NOT_YET_IMPLEMENTED);
}

void vm_idiv(vm_t* vm, const REGISTER dest, const uint32_t arg){
    exit(NOT_YET_IMPLEMENTED);
}

void vm_cmp(vm_t* vm, const REGISTER dest, const uint32_t arg){
    uint32_t destVal = vm->registers[dest];
    uint32_t res = vm->registers[dest] - arg;
    if(res >> 31)
        vm_set_flag(vm, NF);
    else
        vm_clear_flag(vm, NF);
    if(arg > destVal)
        vm_set_flag(vm, CF);
    else
        vm_clear_flag(vm, CF);
    if(destVal >> 31  != arg >> 31 && arg >> 31 == res >> 31)
        vm_set_flag(vm, OF);
    else
        vm_clear_flag(vm, OF);
    if(res == 0)
        vm_set_flag(vm, ZF);
    else
        vm_clear_flag(vm, ZF);
}

void vm_jmp(vm_t* vm, const uint32_t address, const uint8_t cond){
    if(cond)
        vm->registers[PC] = address;
}

void vm_not(vm_t* vm, const REGISTER dest){
    ~vm->registers[dest];
}

void vm_and(vm_t* vm, const REGISTER dest, const uint32_t arg){
    uint32_t res = vm->registers[dest] &= vm->registers[dest];

    if(res >> 31)
        vm_set_flag(vm, NF);
    else
        vm_clear_flag(vm, NF);
    if(res == 0)
        vm_set_flag(vm, ZF);
    else
        vm_clear_flag(vm, ZF);
    vm_clear_flag(vm, CF);
    vm_clear_flag(vm, OF);
}

void vm_or(vm_t* vm, const REGISTER dest, const uint32_t arg){
    uint32_t res = vm->registers[dest] |= vm->registers[dest];

    if(res >> 31)
        vm_set_flag(vm, NF);
    else
        vm_clear_flag(vm, NF);
    if(res == 0)
        vm_set_flag(vm, ZF);
    else
        vm_clear_flag(vm, ZF);
    vm_clear_flag(vm, CF);
    vm_clear_flag(vm, OF);
}

void vm_xor(vm_t* vm, const REGISTER dest, const uint32_t arg){
    uint32_t res = vm->registers[dest] ^= vm->registers[dest];

    if(res >> 31)
        vm_set_flag(vm, NF);
    else
        vm_clear_flag(vm, NF);
    if(res == 0)
        vm_set_flag(vm, ZF);
    else
        vm_clear_flag(vm, ZF);
    vm_clear_flag(vm, CF);
    vm_clear_flag(vm, OF);
}

void vm_ri_op(vm_t* vm, uint32_t instruction, void (*ri_func)(vm_t*, const REGISTER, const uint32_t)){
    const uint32_t val = instruction & 0xfffff;
    const REGISTER dest = (instruction >> 20) & 0xf;
    ri_func(vm, dest, val);
}
void vm_rl_op(vm_t* vm, uint32_t instruction, void (*rl_func)(vm_t*, const REGISTER, const uint32_t)){
    const uint32_t val = vm->memory[vm->registers[PC]++];
    const REGISTER dest = (instruction >> 20) & 0xf;
    rl_func(vm, dest, val);
}
void vm_rr_op(vm_t* vm, uint32_t instruction, void (*rr_func)(vm_t*, const REGISTER, const uint32_t)){
    const REGISTER dest_reg = (instruction >> 20) & 0xf;
    const uint32_t val = vm->registers[instruction & 0xf];
    rr_func(vm, dest_reg, val);
}