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Documentation, and reorganizing macro definitions

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This commit is contained in:
Peter Evans 2017-12-06 21:29:03 -06:00
parent 4af7e4444c
commit ea2b68dc8c
1 changed files with 32 additions and 25 deletions
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57
include/mos6502.h
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@ -10,12 +10,44 @@
*/ */
#define MOS6502_MEMSIZE 65536 #define MOS6502_MEMSIZE 65536
/*
* This is a small macro to make it a bit simpler to set bytes ahead of
* the PC register position; useful in testing.
*/
#define SET_PC_BYTE(cpu, off, byte) \ #define SET_PC_BYTE(cpu, off, byte) \
vm_segment_set(cpu->memory, cpu->PC + off, byte) vm_segment_set(cpu->memory, cpu->PC + off, byte)
/*
* This macro is used to define new instruction handler functions.
*/
#define DEFINE_INST(inst) \ #define DEFINE_INST(inst) \
void mos6502_handle_##inst (mos6502 *cpu, vm_8bit oper) void mos6502_handle_##inst (mos6502 *cpu, vm_8bit oper)
/*
* In some address mode resolution, we must factor the carry bit into
* the arithmetic we perform. In all those cases, if the carry bit is
* set, we must only add 1 to the addition. The carry variable is,
* therefore, the literal value we are adding, rather than a boolean
* signifier.
*/
#define CARRY_BIT() \
vm_8bit carry = 0; \
if (cpu->P & CARRY) carry = 1
/*
* A uniform way of declaring resolve functions for address modes, which
* is useful in the event that we need to change the function signature.
*/
#define DECL_ADDR_MODE(x) \
extern vm_8bit mos6502_resolve_##x (mos6502 *)
/*
* Similarly, a uniform way of declaring instruction handler functions,
* for the same reasons.
*/
#define DECL_INST(x) \
extern void mos6502_handle_##x (mos6502 *, vm_8bit)
typedef struct { typedef struct {
/* /*
* Our memory. * Our memory.
@ -98,31 +130,6 @@ extern vm_8bit mos6502_read_byte(mos6502 *);
extern int mos6502_addr_mode(vm_8bit); extern int mos6502_addr_mode(vm_8bit);
extern mos6502_address_resolver mos6502_get_address_resolver(vm_8bit); extern mos6502_address_resolver mos6502_get_address_resolver(vm_8bit);
/*
* In some address mode resolution, we must factor the carry bit into
* the arithmetic we perform. In all those cases, if the carry bit is
* set, we must only add 1 to the addition. The carry variable is,
* therefore, the literal value we are adding, rather than a boolean
* signifier.
*/
#define CARRY_BIT() \
vm_8bit carry = 0; \
if (cpu->P & CARRY) carry = 1
/*
* A uniform way of declaring resolve functions for address modes, which
* is useful in the event that we need to change the function signature.
*/
#define DECL_ADDR_MODE(x) \
extern vm_8bit mos6502_resolve_##x (mos6502 *)
/*
* Similarly, a uniform way of declaring instruction handler functions,
* for the same reasons.
*/
#define DECL_INST(x) \
extern void mos6502_handle_##x (mos6502 *, vm_8bit)
/* /*
* All of our address modes * All of our address modes
*/ */