1 /*****************************************************************************/
5 /* 6502 specific declarations */
9 /* (C) 1998-2001 Ullrich von Bassewitz */
11 /* D-70597 Stuttgart */
12 /* EMail: uz@musoftware.de */
15 /* This software is provided 'as-is', without any expressed or implied */
16 /* warranty. In no event will the authors be held liable for any damages */
17 /* arising from the use of this software. */
19 /* Permission is granted to anyone to use this software for any purpose, */
20 /* including commercial applications, and to alter it and redistribute it */
21 /* freely, subject to the following restrictions: */
23 /* 1. The origin of this software must not be misrepresented; you must not */
24 /* claim that you wrote the original software. If you use this software */
25 /* in a product, an acknowledgment in the product documentation would be */
26 /* appreciated but is not required. */
27 /* 2. Altered source versions must be plainly marked as such, and must not */
28 /* be misrepresented as being the original software. */
29 /* 3. This notice may not be removed or altered from any source */
32 /*****************************************************************************/
41 /* Possible returns of getcpu() */
46 unsigned char getcpu (void);
47 /* Detect the CPU the program is running on */
51 /* Macros for CPU instructions */
52 #define BRK() __asm__ ("brk")
53 #define CLI() __asm__ ("cli")
54 #define SEI() __asm__ ("sei")
58 /* Struct that holds the registers for the sys function */
60 unsigned char a; /* A register value */
61 unsigned char x; /* X register value */
62 unsigned char y; /* Y register value */
63 unsigned char flags; /* Flags value */
64 unsigned pc; /* Program counter */
67 /* Defines for the flags in the regs structure */
68 #ifdef __OBSOLETE_FLAGS__
69 #define F_NEG 0x80 /* N flag */
70 #define F_OVF 0x40 /* V flag */
71 #define F_BRK 0x10 /* B flag */
72 #define F_DEC 0x08 /* D flag */
73 #define F_IEN 0x04 /* I flag */
74 #define F_ZERO 0x02 /* Z flag */
75 #define F_CARRY 0x01 /* C flag */
78 /* Defines for the flags in the regs structure */
79 #define F6502_N 0x80 /* N flag */
80 #define F6502_V 0x40 /* V flag */
81 #define F6502_B 0x10 /* B flag */
82 #define F6502_D 0x08 /* D flag */
83 #define F6502_I 0x04 /* I flag */
84 #define F6502_Z 0x02 /* Z flag */
85 #define F6502_C 0x01 /* C flag */
87 /* Function to call any machine language subroutine. All registers in the
88 * regs structure are passed into the routine and the results are passed
89 * out. The B flag is ignored on input. The called routine must end with
92 void __fastcall__ _sys (struct regs* r);
96 /* Set and reset the break vector. The given user function is called if
97 * a break occurs. The values of the registers may be read from the brk_...
98 * variables. The value in brk_pc will point to the address that contains
99 * the brk instruction.
100 * The set_brk function will install an exit handler that will reset the
101 * vector if the program ends.
104 extern unsigned char brk_a; /* A register value */
105 extern unsigned char brk_x; /* X register value */
106 extern unsigned char brk_y; /* Y register value */
107 extern unsigned char brk_sr; /* Status register */
108 extern unsigned brk_pc; /* PC value */
110 typedef void (*brk_handler) (void);
111 /* Type of the break handler */
113 void __fastcall__ set_brk (brk_handler f);
114 /* Set the break vector to the given address, return the old address */
116 void reset_brk (void);
117 /* Reset the break vector to the original value */