6502/rk65c02
1
0
Fork 0
mirror of https://github.com/rkujawa/rk65c02.git synced 2025-01-31 06:29:46 +00:00
Code Issues Projects Releases Wiki Activity

Avoid getting instruction definition again when emulating.

Browse Source 
While here try to make program counter incrementation more universal
and flexible.
This commit is contained in:
Radosław Kujawa 2017-01-22 11:07:19 +01:00
parent c7633feb87
commit e763ca0d3a
5 changed files with 25 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
src/emulation.awk
View File

@ -14,7 +14,7 @@ BEGIN {
END {
for (i in emuls)
printf "void %s(rk65c02emu_t *, instruction_t *);\n",i
printf "void %s(rk65c02emu_t *, void *id, instruction_t *);\n",i
print "#endif /* _EMULATION_H_ */"
}

32
src/emulation.c
View File

@ -4,14 +4,11 @@
/* AND - logical AND */
void
emul_and(rk65c02emu_t *e, instruction_t *i)
emul_and(rk65c02emu_t *e, void *id, instruction_t *i)
{
instrdef_t id;
uint8_t rv;
id = instruction_decode(i->opcode);
rv = e->regs.A & (instruction_data_read_1(e, &id, i));
rv = e->regs.A & (instruction_data_read_1(e, (instrdef_t *) id, i));
e->regs.A = rv;
instruction_status_adjust_zero(e, e->regs.A);
@ -20,13 +17,9 @@ emul_and(rk65c02emu_t *e, instruction_t *i)
/* LDA - load to accumulator */
void
emul_lda(rk65c02emu_t *e, instruction_t *i)
emul_lda(rk65c02emu_t *e, void *id, instruction_t *i)
{
instrdef_t id;
id = instruction_decode(i->opcode);
e->regs.A = instruction_data_read_1(e, &id, i);
e->regs.A = instruction_data_read_1(e, (instrdef_t *) id, i);
instruction_status_adjust_zero(e, e->regs.A);
instruction_status_adjust_negative(e, e->regs.A);
@ -34,21 +27,20 @@ emul_lda(rk65c02emu_t *e, instruction_t *i)
/* NOP - do nothing */
void
emul_nop(rk65c02emu_t *e, instruction_t *i)
emul_nop(rk65c02emu_t *e, void *id, instruction_t *i)
{
/* printf("nop!\n"); */
}
/* PHA - push accumulator to stack */
void
emul_pha(rk65c02emu_t *e, instruction_t *i)
emul_pha(rk65c02emu_t *e, void *id, instruction_t *i)
{
stack_push(e, e->regs.A);
}
/* PLA - pull from stack to accumulator */
void
emul_pla(rk65c02emu_t *e, instruction_t *i)
emul_pla(rk65c02emu_t *e, void *id, instruction_t *i)
{
e->regs.A = stack_pop(e);
@ -58,19 +50,15 @@ emul_pla(rk65c02emu_t *e, instruction_t *i)
/* STP - stop the processor */
void
emul_stp(rk65c02emu_t *e, instruction_t *i)
emul_stp(rk65c02emu_t *e, void *id, instruction_t *i)
{
e->state = STOPPED;
}
/* STZ - store zero */
void
emul_stz(rk65c02emu_t *e, instruction_t *i)
emul_stz(rk65c02emu_t *e, void *id, instruction_t *i)
{
instrdef_t id;
id = instruction_decode(i->opcode);
instruction_data_write_1(e, &id, i, 0);
instruction_data_write_1(e, id, i, 0);
}

7
src/instruction.c
View File

@ -278,3 +278,10 @@ stack_pop(rk65c02emu_t *e)
return val;
}
/* increment program counter based on instruction size (opcode + operands) */
void
program_counter_increment(rk65c02emu_t *e, instrdef_t *id)
{
e->regs.PC += id->size;
}

3
src/instruction.h
View File

@ -34,7 +34,7 @@ struct instrdef {
const char *mnemonic;
addressing_t mode;
uint8_t size;
void (*emul)(rk65c02emu_t *e, instruction_t *i);
void (*emul)(rk65c02emu_t *e, void *id, instruction_t *i);
};
typedef struct instrdef instrdef_t;
@ -49,5 +49,6 @@ void instruction_status_adjust_zero(rk65c02emu_t *, uint8_t);
void instruction_status_adjust_negative(rk65c02emu_t *, uint8_t);
void stack_push(rk65c02emu_t *, uint8_t);
uint8_t stack_pop(rk65c02emu_t *);
void program_counter_increment(rk65c02emu_t *, instrdef_t *);
#endif /* _INSTRUCTION_H_ */

11
src/rk65c02.c
View File

@ -32,16 +32,15 @@ rk65c02_start(rk65c02emu_t *e) {
i = instruction_fetch(e->bus, e->regs.PC);
id = instruction_decode(i.opcode);
if (id.emul != NULL)
id.emul(e, &i);
else {
if (id.emul != NULL) {
id.emul(e, &id, &i);
/* if (!instruction_modify_pc) */
program_counter_increment(e, &id);
} else {
printf("unimplemented opcode %X @ %X\n", i.opcode,
e->regs.PC);
e->state = STOPPED;
}
e->regs.PC += id.size;
}
}
/*