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Diffstat (limited to 'contrib/nosefart/nes6502.h')
| -rw-r--r-- | contrib/nosefart/nes6502.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/contrib/nosefart/nes6502.h b/contrib/nosefart/nes6502.h new file mode 100644 index 000000000..8713304ec --- /dev/null +++ b/contrib/nosefart/nes6502.h @@ -0,0 +1,157 @@ +/* +** Nofrendo (c) 1998-2000 Matthew Conte (matt@conte.com) +** +** +** This program is free software; you can redistribute it and/or +** modify it under the terms of version 2 of the GNU Library General +** Public License as published by the Free Software Foundation. +** +** This program is distributed in the hope that it will be useful, +** but WITHOUT ANY WARRANTY; without even the implied warranty of +** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +** Library General Public License for more details. To obtain a +** copy of the GNU Library General Public License, write to the Free +** Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +** +** Any permitted reproduction of these routines, in whole or in part, +** must bear this legend. +** +** +** nes6502.h +** +** NES custom 6502 CPU definitions / prototypes +** $Id: nes6502.h,v 1.2 2003/12/05 15:55:01 f1rmb Exp $ +*/ + +/* straitm */ +#include "types.h" + +/* NOTE: 16-bit addresses avoided like the plague: use 32-bit values +** wherever humanly possible +*/ +#ifndef _NES6502_H_ +#define _NES6502_H_ + +/* Define this to enable decimal mode in ADC / SBC (not needed in NES) */ +/*#define NES6502_DECIMAL*/ + +/* number of bank pointers the CPU emulation core handles */ +#ifdef NSF_PLAYER +#define NES6502_4KBANKS +#endif + +#ifdef NES6502_4KBANKS +#define NES6502_NUMBANKS 16 +#define NES6502_BANKSHIFT 12 +#else +#define NES6502_NUMBANKS 8 +#define NES6502_BANKSHIFT 13 +#endif + +#define NES6502_BANKMASK ((0x10000 / NES6502_NUMBANKS) - 1) + +/* Add memory access control flags. This is a ram shadow memory that holds + * for each memory bytes access flags for read, write and execute access. + * The nes6502_mem_access holds all new access (all mode all location). It is + * used to determine if the player has loop in playing time calculation. + */ +#ifdef NES6502_MEM_ACCESS_CTRL +extern uint8 nes6502_mem_access; +# define NES6502_READ_ACCESS 1 +# define NES6502_WRITE_ACCESS 2 +# define NES6502_EXE_ACCESS 4 +#endif /* #ifdef NES6502_MEM_ACCESS_CTRL */ + +/* P (flag) register bitmasks */ +#define N_FLAG 0x80 +#define V_FLAG 0x40 +#define R_FLAG 0x20 /* Reserved, always 1 */ +#define B_FLAG 0x10 +#define D_FLAG 0x08 +#define I_FLAG 0x04 +#define Z_FLAG 0x02 +#define C_FLAG 0x01 + +/* Vector addresses */ +#define NMI_VECTOR 0xFFFA +#define RESET_VECTOR 0xFFFC +#define IRQ_VECTOR 0xFFFE + +/* cycle counts for interrupts */ +#define INT_CYCLES 7 +#define RESET_CYCLES 6 + +#define NMI_MASK 0x01 +#define IRQ_MASK 0x02 + +/* Stack is located on 6502 page 1 */ +#define STACK_OFFSET 0x0100 + +typedef struct +{ + uint32 min_range, max_range; + uint8 (*read_func)(uint32 address); +} nes6502_memread; + +typedef struct +{ + uint32 min_range, max_range; + void (*write_func)(uint32 address, uint8 value); +} nes6502_memwrite; + +typedef struct +{ + uint8 * mem_page[NES6502_NUMBANKS]; /* memory page pointers */ +#ifdef NES6502_MEM_ACCESS_CTRL + uint8 * acc_mem_page[NES6502_NUMBANKS]; /* memory access page pointer */ +#endif + nes6502_memread *read_handler; + nes6502_memwrite *write_handler; + int dma_cycles; + uint32 pc_reg; + uint8 a_reg, p_reg, x_reg, y_reg, s_reg; + uint8 int_pending; +} nes6502_context; + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/* Functions which govern the 6502's execution */ +extern void nes6502_init(void); +extern void nes6502_reset(void); +extern int nes6502_execute(int total_cycles); +extern void nes6502_nmi(void); +extern void nes6502_irq(void); +extern uint8 nes6502_getbyte(uint32 address); +extern uint32 nes6502_getcycles(boolean reset_flag); +extern void nes6502_setdma(int cycles); + +#ifdef NES6502_MEM_ACCESS_CTRL +extern void nes6502_chk_mem_access(uint8 * access, int flags); +#else +#define nes6502_chk_mem_access(access,flags) +#endif + +/* Context get/set */ +extern void nes6502_setcontext(nes6502_context *cpu); +extern void nes6502_getcontext(nes6502_context *cpu); + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif /* _NES6502_H_ */ + +/* +** $Log: nes6502.h,v $ +** Revision 1.2 2003/12/05 15:55:01 f1rmb +** cleanup phase II. use xprintf when it's relevant, use xine_xmalloc when it's relevant too. Small other little fix (can't remember). Change few internal function prototype because it xine_t pointer need to be used if some xine's internal sections. NOTE: libdvd{nav,read} is still too noisy, i will take a look to made it quit, without invasive changes. To be continued... +** +** Revision 1.1 2003/01/08 07:04:35 tmmm +** initial import of Nosefart sources +** +** Revision 1.4 2000/06/09 15:12:25 matt +** initial revision +** +*/ |