This commit is contained in:
neauoire 2021-02-08 14:08:58 -08:00
parent d84e982031
commit 8c6ad15d03
3 changed files with 70 additions and 72 deletions

78
cpu.c
View File

@ -13,54 +13,23 @@ WITH REGARD TO THIS SOFTWARE.
#include "cpu.h" #include "cpu.h"
#define FLAG_HALT 0x01
#define FLAG_SHORT 0x02
#define FLAG_SIGN 0x04
#define FLAG_COND 0x08
Cpu cpu; Cpu cpu;
#pragma mark - Helpers #pragma mark - Helpers
void void
setflag(Cpu *c, char flag, int b) setflag(Uint8 *status, char flag, int b)
{ {
if(b) if(b)
c->status |= flag; *status |= flag;
else else
c->status &= (~flag); *status &= (~flag);
} }
int int
getflag(Cpu *c, char flag) getflag(Uint8 *status, char flag)
{ {
return c->status & flag; return *status & flag;
}
void
echos(Stack8 *s, Uint8 len, char *name)
{
int i;
printf("\n%s\n", name);
for(i = 0; i < len; ++i) {
if(i % 16 == 0)
printf("\n");
printf("%02x%c", s->dat[i], s->ptr == i ? '<' : ' ');
}
printf("\n\n");
}
void
echom(Memory *m, Uint8 len, char *name)
{
int i;
printf("\n%s\n", name);
for(i = 0; i < len; ++i) {
if(i % 16 == 0)
printf("\n");
printf("%02x ", m->dat[i]);
}
printf("\n\n");
} }
#pragma mark - Operations #pragma mark - Operations
@ -77,11 +46,10 @@ Uint8 wspeek8(Cpu *c, Uint8 o) { return c->wst.dat[c->wst.ptr - o]; }
Uint16 wspeek16(Cpu *c, Uint8 o) { return bytes2short(c->wst.dat[c->wst.ptr - o], c->wst.dat[c->wst.ptr - o + 1]); } Uint16 wspeek16(Cpu *c, Uint8 o) { return bytes2short(c->wst.dat[c->wst.ptr - o], c->wst.dat[c->wst.ptr - o + 1]); }
Uint16 rspop16(Cpu *c) { return c->rst.dat[--c->rst.ptr]; } Uint16 rspop16(Cpu *c) { return c->rst.dat[--c->rst.ptr]; }
void rspush16(Cpu *c, Uint16 a) { c->rst.dat[c->rst.ptr++] = a; } void rspush16(Cpu *c, Uint16 a) { c->rst.dat[c->rst.ptr++] = a; }
/* I/O */ /* I/O */
void op_brk(Cpu *c) { setflag(c,FLAG_HALT, 1); } void op_brk(Cpu *c) { setflag(&c->status,FLAG_HALT, 1); }
void op_lit(Cpu *c) { c->literal += c->ram.dat[c->ram.ptr++]; } void op_lit(Cpu *c) { c->literal += c->ram.dat[c->ram.ptr++]; }
void op_nop(Cpu *c) { printf("NOP");} void op_nop(Cpu *c) { (void)c; printf("NOP");}
void op_ldr(Cpu *c) { wspush8(c, c->ram.dat[wspop16(c)]); } void op_ldr(Cpu *c) { wspush8(c, c->ram.dat[wspop16(c)]); }
void op_str(Cpu *c) { c->ram.dat[wspop16(c)] = wspop8(c); } void op_str(Cpu *c) { c->ram.dat[wspop16(c)] = wspop8(c); }
/* Logic */ /* Logic */
@ -148,7 +116,7 @@ Uint8 opr[][2] = {
int int
error(Cpu *c, char *name, int id) error(Cpu *c, char *name, int id)
{ {
printf("Error: %s[%04x], at 0x%04x\n", name, id, c->counter); printf("Error: %s#%04x, at 0x%04x\n", name, id, c->counter);
return 0; return 0;
} }
@ -176,16 +144,16 @@ int
doopcode(Cpu *c, Uint8 instr) doopcode(Cpu *c, Uint8 instr)
{ {
Uint8 op = instr & 0x1f; Uint8 op = instr & 0x1f;
setflag(c, FLAG_SHORT, (instr >> 5) & 1); setflag(&c->status, FLAG_SHORT, (instr >> 5) & 1);
setflag(c, FLAG_SIGN, (instr >> 6) & 1); /* usused */ setflag(&c->status, FLAG_SIGN, (instr >> 6) & 1); /* usused */
setflag(c, FLAG_COND, (instr >> 7) & 1); setflag(&c->status, FLAG_COND, (instr >> 7) & 1);
if(getflag(c, FLAG_SHORT)) if(getflag(&c->status, FLAG_SHORT))
op += 16; op += 16;
if(c->wst.ptr < opr[op][0]) if(c->wst.ptr < opr[op][0])
return error(c, "Stack underflow", op); return error(c, "Stack underflow", op);
if(c->wst.ptr + opr[op][1] - opr[op][0] >= 255) if(c->wst.ptr + opr[op][1] - opr[op][0] >= 255)
return error(c, "Stack overflow", instr); return error(c, "Stack overflow", instr);
if(!getflag(c, FLAG_COND) || (getflag(c, FLAG_COND) && wspop8(c))) if(!getflag(&c->status, FLAG_COND) || (getflag(&c->status, FLAG_COND) && wspop8(c)))
(*ops[op])(c); (*ops[op])(c);
dodevices(c); dodevices(c);
return 1; return 1;
@ -203,23 +171,15 @@ eval(Cpu *c)
} }
int int
load(Cpu *c, FILE *f) load(Cpu *c, char *filepath)
{ {
FILE *f;
if(!(f = fopen(filepath, "rb")))
return error(c, "Missing input.", 0);
fread(c->ram.dat, sizeof(c->ram.dat), 1, f); fread(c->ram.dat, sizeof(c->ram.dat), 1, f);
return 1; return 1;
} }
void
echof(Cpu *c)
{
printf("ended @ %d steps | hf: %x sf: %x sf: %x cf: %x\n",
c->counter,
getflag(c, FLAG_HALT) != 0,
getflag(c, FLAG_SHORT) != 0,
getflag(c, FLAG_SIGN) != 0,
getflag(c, FLAG_COND) != 0);
}
void void
reset(Cpu *c) reset(Cpu *c)
{ {
@ -238,12 +198,12 @@ boot(Cpu *c)
c->verror = mempeek16(c, 0xfffe); c->verror = mempeek16(c, 0xfffe);
/* eval reset */ /* eval reset */
c->ram.ptr = c->vreset; c->ram.ptr = c->vreset;
setflag(c, FLAG_HALT, 0); setflag(&c->status, FLAG_HALT, 0);
while(!(c->status & FLAG_HALT) && eval(c)) while(!(c->status & FLAG_HALT) && eval(c))
c->counter++; c->counter++;
/* eval frame */ /* eval frame */
c->ram.ptr = c->vframe; c->ram.ptr = c->vframe;
setflag(c, FLAG_HALT, 0); setflag(&c->status, FLAG_HALT, 0);
while(!(c->status & FLAG_HALT) && eval(c)) while(!(c->status & FLAG_HALT) && eval(c))
c->counter++; c->counter++;
return 1; return 1;

12
cpu.h
View File

@ -14,6 +14,11 @@ WITH REGARD TO THIS SOFTWARE.
typedef unsigned char Uint8; typedef unsigned char Uint8;
typedef unsigned short Uint16; typedef unsigned short Uint16;
#define FLAG_HALT 0x01
#define FLAG_SHORT 0x02
#define FLAG_SIGN 0x04
#define FLAG_COND 0x08
typedef struct { typedef struct {
Uint8 ptr; Uint8 ptr;
Uint8 dat[256]; Uint8 dat[256];
@ -37,9 +42,8 @@ typedef struct {
Memory ram; Memory ram;
} Cpu; } Cpu;
void setflag(Uint8 *status, char flag, int b);
int getflag(Uint8 *status, char flag);
int error(Cpu *c, char *name, int id); int error(Cpu *c, char *name, int id);
int load(Cpu *c, FILE *f); int load(Cpu *c, char *filepath);
int boot(Cpu *c); int boot(Cpu *c);
void echof(Cpu *c);
void echom(Memory *m, Uint8 len, char *name);
void echos(Stack8 *s, Uint8 len, char *name);

42
uxn.c
View File

@ -12,16 +12,50 @@ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE. WITH REGARD TO THIS SOFTWARE.
*/ */
void
echos(Stack8 *s, Uint8 len, char *name)
{
int i;
printf("\n%s\n", name);
for(i = 0; i < len; ++i) {
if(i % 16 == 0)
printf("\n");
printf("%02x%c", s->dat[i], s->ptr == i ? '<' : ' ');
}
printf("\n\n");
}
void
echom(Memory *m, Uint8 len, char *name)
{
int i;
printf("\n%s\n", name);
for(i = 0; i < len; ++i) {
if(i % 16 == 0)
printf("\n");
printf("%02x ", m->dat[i]);
}
printf("\n\n");
}
void
echof(Cpu *c)
{
printf("ended @ %d steps | hf: %x sf: %x sf: %x cf: %x\n",
c->counter,
getflag(&c->status, FLAG_HALT) != 0,
getflag(&c->status, FLAG_SHORT) != 0,
getflag(&c->status, FLAG_SIGN) != 0,
getflag(&c->status, FLAG_COND) != 0);
}
int int
main(int argc, char *argv[]) main(int argc, char *argv[])
{ {
FILE *f;
Cpu cpu; Cpu cpu;
if(argc < 2) if(argc < 2)
return error(&cpu, "No input.", 0); return error(&cpu, "No input.", 0);
if(!(f = fopen(argv[1], "rb"))) if(!load(&cpu, argv[1]))
return error(&cpu, "Missing input.", 0);
if(!load(&cpu, f))
return error(&cpu, "Load error", 0); return error(&cpu, "Load error", 0);
if(!boot(&cpu)) if(!boot(&cpu))
return error(&cpu, "Boot error", 0); return error(&cpu, "Boot error", 0);