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Show the dereferenced value for a given address

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This commit is contained in:
Peter Evans 2018-01-19 12:18:24 -06:00
parent 2c319399d2
commit 6b160c6ca2
3 changed files with 26 additions and 6 deletions
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2
include/mos6502.h
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@ -149,7 +149,7 @@ extern void mos6502_set_status(mos6502 *, vm_8bit);
* Below are some functions that are defined in mos6502.addr.c
*/
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(int);
/*
* All of our address modes

6
src/mos6502.c
View File

@ -352,7 +352,7 @@ mos6502_execute(mos6502 *cpu)
// First, we need to know how to resolve our effective address and
// how to execute anything.
resolver = mos6502_get_address_resolver(opcode);
resolver = mos6502_get_address_resolver(mos6502_addr_mode(opcode));
handler = mos6502_get_instruction_handler(opcode);
// The operand is the effective operand, the value that the
@ -454,9 +454,9 @@ mos6502_would_jump(int inst_code)
* cpu) that an instruction will use.
*/
mos6502_address_resolver
mos6502_get_address_resolver(vm_8bit opcode)
mos6502_get_address_resolver(int addr_mode)
{
switch (mos6502_addr_mode(opcode)) {
switch (addr_mode) {
case ACC: return mos6502_resolve_acc;
case ABS: return mos6502_resolve_abs;
case ABX: return mos6502_resolve_abx;

24
src/mos6502.dis.c
View File

@ -12,6 +12,7 @@
static char s_inst[4],
s_oper[10],
s_value[3],
s_label[13],
s_state[51],
s_bytes[12];
@ -94,38 +95,53 @@ mos6502_dis_operand(mos6502 *cpu,
{
int rel_address;
int ind_address;
vm_8bit eff_value;
mos6502_address_resolver resolv;
resolv = mos6502_get_address_resolver(addr_mode);
eff_value = resolv(cpu);
switch (addr_mode) {
case ACC:
break;
case ABS:
snprintf(str, len, "$%04X", value);
snprintf(s_value, sizeof(s_value), "%02x", eff_value);
break;
case ABX:
snprintf(str, len, "$%04X,X", value);
eff_value = resolv(cpu);
snprintf(s_value, sizeof(s_value), "%02x", eff_value);
break;
case ABY:
snprintf(str, len, "$%04X,Y", value);
snprintf(s_value, sizeof(s_value), "%02x", eff_value);
break;
case IMM:
snprintf(str, len, "#$%02X", value);
snprintf(s_value, sizeof(s_value), "%02x", eff_value);
break;
case IMP:
snprintf(s_value, sizeof(s_value), "%02X", 0);
break;
case IND:
ind_address = mos6502_get(cpu, value + 1) << 8;
ind_address |= mos6502_get(cpu, value);
if (jump_table[ind_address]) {
mos6502_dis_label(str, len, ind_address);
snprintf(s_value, sizeof(s_value), "%02X", 0);
} else {
snprintf(str, len, "($%04X)", value);
snprintf(s_value, sizeof(s_value), "%02x", eff_value);
}
break;
case IDX:
snprintf(str, len, "($%02X,X)", value);
snprintf(s_value, sizeof(s_value), "%02x", eff_value);
break;
case IDY:
snprintf(str, len, "($%02X),Y", value);
snprintf(s_value, sizeof(s_value), "%02x", eff_value);
break;
case REL:
rel_address = address + value;
@ -134,17 +150,21 @@ mos6502_dis_operand(mos6502 *cpu,
}
mos6502_dis_label(str, len, rel_address);
snprintf(s_value, sizeof(s_value), "%02x", eff_value);
break;
case ZPG:
// We add a couple of spaces here to help our output
// comments line up.
snprintf(str, len, "$%02X", value);
snprintf(s_value, sizeof(s_value), "%02x", eff_value);
break;
case ZPX:
snprintf(str, len, "$%02X,X", value);
snprintf(s_value, sizeof(s_value), "%02x", eff_value);
break;
case ZPY:
snprintf(str, len, "$%02X,Y", value);
snprintf(s_value, sizeof(s_value), "%02x", eff_value);
break;
}
}
@ -301,9 +321,9 @@ mos6502_dis_opcode(mos6502 *cpu, FILE *stream, int address)
// what the PC was at the point of this opcode sequence; two,
// the opcode;
snprintf(s_state, sizeof(s_state) - 1,
"pc:%02x%02x cy:%02d val:%04x a:%02x x:%02x y:%02x p:%02x s:%02x",
"pc:%02x%02x cy:%02d val:%2s a:%02x x:%02x y:%02x p:%02x s:%02x",
cpu->PC >> 8, cpu->PC & 0xff,
mos6502_cycles(cpu, opcode), operand,
mos6502_cycles(cpu, opcode), s_value,
cpu->A, cpu->X, cpu->Y, cpu->P, cpu->S);
// And three, the operand, if any. Remembering that the operand