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#include "chip8.h"
uint8_t key[KEY_SIZE]; // hex key input
uint32_t video[WIDTH*HEIGHT]; // video memory TODO: video should be 8 bit not 32
uint8_t V[16]; // registers - 0x0 to 0xF
uint16_t I; // special I register, stores addresses
uint16_t PC; // program counter
uint8_t SP; // stack pointer
uint16_t stack[STACK_SIZE]; // stack, for address storage when using subroutines, maximum of 16 levels of nested subroutines
uint8_t memory[MEMORY_SIZE]; // 4KB of program memory
int
load_rom(char *rom)
{
int ret = 1;
printf("loading rom %s..\n", rom);
FILE *romfile;
romfile = fopen(rom, "rb");
if (romfile == NULL)
{
fprintf(stderr, "cannot read rom %s: %s\n", rom, strerror(errno));
ret = 0;
}
/* read a maximum of MAX_ROM_SIZE bytes into memory starting after the reserved memory */
fread(&memory[0x200], 1, MAX_ROM_SIZE, romfile);
fclose(romfile);
return ret;
}
void
chip8_init()
{
/* clear everything */
memset(key, 0, 15);
memset(video, 0, (WIDTH*HEIGHT) * sizeof(uint32_t));
memset(V, 0, 16);
memset(stack, 0, (STACK_SIZE) * sizeof(uint16_t));
memset(memory, 0, MEMORY_SIZE);
}
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