mirror of
https://github.com/andwati/mos-6502.git
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andwati
0dcd2ed687
- Added `state.c` to handle saving and loading the state of the CPU and Bus. - Implemented CRC32 checksum for data integrity verification during state operations. - Enhanced `README.md` in tests/roms to document new test commands for decimal, interrupt, Apple I, and nestest. - Created new test files: `run_apple1.c`, `run_decimal.c`, `run_interrupt.c`, `run_nestest.c`, and `run_vectors.c` to validate the new features. - Updated `run_tests.c` to include tests for state saving/loading and other functionalities. - Introduced `test_vectors.py` to facilitate downloading and running JSON test vectors for opcode verification.
46 lines
2.2 KiB
C
46 lines
2.2 KiB
C
#include <errno.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "state.h"
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enum { HEADER_SIZE=25, STATE_SIZE=HEADER_SIZE+MEM_SIZE+4 };
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static uint32_t crc32(const uint8_t *data,size_t size)
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{
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uint32_t crc=0xFFFFFFFFu;
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for(size_t i=0;i<size;i++){crc^=data[i];for(unsigned bit=0;bit<8;bit++)crc=(crc>>1)^((uint32_t)-(int32_t)(crc&1)&0xEDB88320u);}
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return ~crc;
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}
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static void put32(uint8_t *p,uint32_t v){p[0]=(uint8_t)v;p[1]=(uint8_t)(v>>8);p[2]=(uint8_t)(v>>16);p[3]=(uint8_t)(v>>24);}
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static uint32_t get32(const uint8_t *p){return (uint32_t)p[0]|(uint32_t)p[1]<<8|(uint32_t)p[2]<<16|(uint32_t)p[3]<<24;}
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int state_save(const char *path,const CPU6502 *c,const Bus6502 *b)
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{
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uint8_t *data=calloc(1,STATE_SIZE);FILE *f;size_t wrote;
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if(!data)return ENOMEM;
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memcpy(data,"MOS6502",7);data[8]=2;data[9]=c->A;data[10]=c->X;data[11]=c->Y;
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data[12]=c->SP;data[13]=c->P;data[14]=(uint8_t)c->PC;data[15]=(uint8_t)(c->PC>>8);
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data[16]=c->nmi_pending;data[17]=c->irq_asserted;data[18]=c->decimal_enabled;
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data[19]=b->keyboard;data[20]=b->easy6502_io;put32(data+21,b->rng_state);
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memcpy(data+HEADER_SIZE,b->memory.data,MEM_SIZE);put32(data+HEADER_SIZE+MEM_SIZE,crc32(data,HEADER_SIZE+MEM_SIZE));
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f=fopen(path,"wb");if(!f){int e=errno;free(data);return e;}
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wrote=fwrite(data,1,STATE_SIZE,f);free(data);if(fclose(f)!=0||wrote!=STATE_SIZE)return EIO;return 0;
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}
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int state_load(const char *path,CPU6502 *c,Bus6502 *b)
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{
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uint8_t *data=malloc(STATE_SIZE);FILE *f;size_t got;int extra;
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if(!data)return ENOMEM;
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f=fopen(path,"rb");
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if(!f){int e=errno;free(data);return e;}
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got=fread(data,1,STATE_SIZE,f);extra=fgetc(f);fclose(f);
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if(got!=STATE_SIZE||extra!=EOF||memcmp(data,"MOS6502",7)||data[8]!=2||
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get32(data+HEADER_SIZE+MEM_SIZE)!=crc32(data,HEADER_SIZE+MEM_SIZE)){free(data);return EINVAL;}
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c->A=data[9];c->X=data[10];c->Y=data[11];c->SP=data[12];c->P=data[13];
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c->PC=(uint16_t)data[14]|(uint16_t)data[15]<<8;c->nmi_pending=data[16]!=0;c->irq_asserted=data[17]!=0;c->decimal_enabled=data[18]!=0;
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b->keyboard=data[19];b->easy6502_io=data[20]!=0;b->rng_state=get32(data+21);
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memcpy(b->memory.data,data+HEADER_SIZE,MEM_SIZE);b->framebuffer_dirty=true;free(data);return 0;
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}
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