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Turned sim65 into a lightweight cc65 execution environment.

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The sim65 source code has been a construction site for over a decade.
I was looking for a simple cc65 program execution environment for
regression tests. So I decided to re-purpose sim65 for that task by
removing about everything but the 6502 emulation.

There's no memory mapped i/o emulation whatsoever. Rather exit(),
open(), close(), read() and write() calls are supported by mapping
them through a thin paravirtualization layer to the corresponding
host os functions.

Note: The sim65 6502 emulation provides means to switch between
6502 and 65C02 emulation but currently there are no actual 65C02
opcodes implemented.
This commit is contained in:
Oliver Schmidt
2013-05-20 20:20:14 +02:00
parent 753aa29b15
commit 3a028fb621
42 changed files with 3316 additions and 9482 deletions
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106
src/sim65/6502.h Normal file
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/*****************************************************************************/
/* */
/* 6502.h */
/* */
/* CPU core for the 6502 */
/* */
/* */
/* */
/* (C) 2003-2012, Ullrich von Bassewitz */
/* Roemerstrasse 52 */
/* D-70794 Filderstadt */
/* EMail: uz@cc65.org */
/* */
/* */
/* This software is provided 'as-is', without any expressed or implied */
/* warranty. In no event will the authors be held liable for any damages */
/* arising from the use of this software. */
/* */
/* Permission is granted to anyone to use this software for any purpose, */
/* including commercial applications, and to alter it and redistribute it */
/* freely, subject to the following restrictions: */
/* */
/* 1. The origin of this software must not be misrepresented; you must not */
/* claim that you wrote the original software. If you use this software */
/* in a product, an acknowledgment in the product documentation would be */
/* appreciated but is not required. */
/* 2. Altered source versions must be plainly marked as such, and must not */
/* be misrepresented as being the original software. */
/* 3. This notice may not be removed or altered from any source */
/* distribution. */
/* */
/*****************************************************************************/
#ifndef _6502_H
#define _6502_H
/*****************************************************************************/
/* Data */
/*****************************************************************************/
/* Supported CPUs */
typedef enum CPUType {
CPU_6502,
CPU_65C02
} CPUType;
/* Current CPU */
extern CPUType CPU;
/* 6502 CPU registers */
typedef struct CPURegs CPURegs;
struct CPURegs {
unsigned AC; /* Accumulator */
unsigned XR; /* X register */
unsigned YR; /* Y register */
unsigned ZR; /* Z register */
unsigned SR; /* Status register */
unsigned SP; /* Stackpointer */
unsigned PC; /* Program counter */
};
/* Status register bits */
#define CF 0x01 /* Carry flag */
#define ZF 0x02 /* Zero flag */
#define IF 0x04 /* Interrupt flag */
#define DF 0x08 /* Decimal flag */
#define BF 0x10 /* Break flag */
#define OF 0x40 /* Overflow flag */
#define SF 0x80 /* Sign flag */
/*****************************************************************************/
/* Code */
/*****************************************************************************/
void Reset (void);
/* Generate a CPU RESET */
void IRQRequest (void);
/* Generate an IRQ */
void NMIRequest (void);
/* Generate an NMI */
unsigned ExecuteInsn (void);
/* Execute one CPU instruction. Return the number of clock cycles for the
* executed instruction.
*/
unsigned long GetCycles (void);
/* Return the total number of clock cycles executed */
/* End of 6502.h */
#endif