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finishing touches for restructure

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This commit is contained in:
Yuvia 2025-09-09 15:43:34 +00:00
parent d5155e7cb7
commit 1f6b0e1344
11 changed files with 51 additions and 39 deletions
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6.out Executable file
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a.out Normal file
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cpu.6 Normal file
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41
cpu.c
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@ -3,32 +3,31 @@
#include "dat.h" #include "dat.h"
#include "fns.h" #include "fns.h"
u8int *mem;
u8int rA, rS, rX, rY, rP; u8int rA, rS, rX, rY, rP;
u16int pc; u16int pc;
int irq, nmi; int irq, nmi;
static void void
push8(u8int v) push8(u8int v)
{ {
memwrite(0x100 | rS--, v); memwrite(0x100 | rS--, v);
} }
static void void
push16(u16int v) push16(u16int v)
{ {
memwrite(0x100 | rS--, v >> 8); memwrite(0x100 | rS--, v >> 8);
memwrite(0x100 | rS--, v); memwrite(0x100 | rS--, v);
} }
static u8int u8int
pop8(void) pop8(void)
{ {
return memread(0x100 | ++rS); return memread(0x100 | ++rS);
} }
static u16int u16int
pop16(void) pop16(void)
{ {
u16int v; u16int v;
@ -38,13 +37,13 @@ pop16(void)
return v; return v;
} }
static u8int u8int
fetch8(void) fetch8(void)
{ {
return memread(pc++); return memread(pc++);
} }
static u16int u16int
fetch16(void) fetch16(void)
{ {
u16int r; u16int r;
@ -54,7 +53,7 @@ fetch16(void)
return r; return r;
} }
static void void
nz(u8int v) nz(u8int v)
{ {
rP &= ~(Negative | Zero); rP &= ~(Negative | Zero);
@ -64,7 +63,7 @@ nz(u8int v)
rP |= Zero; rP |= Zero;
} }
static void void
adc(u8int d) adc(u8int d)
{ {
int r; int r;
@ -78,7 +77,7 @@ adc(u8int d)
if(rA == 0) rP |= Zero; if(rA == 0) rP |= Zero;
} }
static void void
sbc(u8int d) sbc(u8int d)
{ {
int r; int r;
@ -92,7 +91,7 @@ sbc(u8int d)
if(rA & 0x80) rP |= Negative; if(rA & 0x80) rP |= Negative;
} }
static void void
asl(u16int a) asl(u16int a)
{ {
u8int v; u8int v;
@ -109,7 +108,7 @@ asl(u16int a)
memwrite(a, v); memwrite(a, v);
} }
static void void
lsr(u16int a) lsr(u16int a)
{ {
u8int v; u8int v;
@ -123,7 +122,7 @@ lsr(u16int a)
memwrite(a, v); memwrite(a, v);
} }
static void void
rol(u16int a) rol(u16int a)
{ {
u8int v, b; u8int v, b;
@ -138,7 +137,7 @@ rol(u16int a)
memwrite(a, v); memwrite(a, v);
} }
static void void
ror(u16int a) ror(u16int a)
{ {
u8int v, b; u8int v, b;
@ -153,7 +152,7 @@ ror(u16int a)
memwrite(a, v); memwrite(a, v);
} }
static void void
cmp(u8int A, u8int B) cmp(u8int A, u8int B)
{ {
rP &= ~(Negative | Zero | Carry); rP &= ~(Negative | Zero | Carry);
@ -162,7 +161,7 @@ cmp(u8int A, u8int B)
if((A - B) & 0x80) rP |= Negative; if((A - B) & 0x80) rP |= Negative;
} }
static void void
inc(u16int a) inc(u16int a)
{ {
u8int v; u8int v;
@ -173,7 +172,7 @@ inc(u16int a)
memwrite(a, v); memwrite(a, v);
} }
static void void
dec(u16int a) dec(u16int a)
{ {
u8int v; u8int v;
@ -184,7 +183,7 @@ dec(u16int a)
memwrite(a, v); memwrite(a, v);
} }
static int int
branch(void) branch(void)
{ {
s8int t; s8int t;
@ -200,7 +199,7 @@ branch(void)
return 3; return 3;
} }
static u16int u16int
aindX(void) aindX(void)
{ {
u8int r; u8int r;
@ -212,7 +211,7 @@ aindX(void)
return b; return b;
} }
static u16int u16int
aindY(int *p) aindY(int *p)
{ {
u8int r; u8int r;
@ -225,7 +224,7 @@ aindY(int *p)
return b; return b;
} }
static void void
interrupt(int nmi, int brk) interrupt(int nmi, int brk)
{ {
push16(pc); push16(pc);

8
fns.h
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@ -1,5 +1,5 @@
int step(void); extern int step(void);
u8int memread(u16int); extern u8int memread(u16int);
void memwrite(u16int, u8int); extern void memwrite(u16int, u8int);
static u16int fetch16(void); extern u16int fetch16(void);

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15
main.c
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@ -6,7 +6,7 @@
void void
usage(void) usage(void)
{ {
fprint(2, "usage: %s [ -s target speed ] [ prog ]\n", argv0); fprint(2, "usage: %s [ -s target cycle length ] prog\n", argv0);
exits("usage"); exits("usage");
} }
@ -23,14 +23,14 @@ openprog(char *f)
sysfatal("cannot open program: %r"); sysfatal("cannot open program: %r");
d = dirfstat(fd); d = dirfstat(fd);
if(d->length > 0xFF00) if(d->length > 0xFF00)
sysfatal("program too big: size does not permit whole zp access"); sysfatal("program too big: cannot be bigger than $ff00");
romptr = mem+32768; romptr = mem+32768;
romptr = romptr + 32768 - d->length; romptr += 32768 - d->length;
s = romptr-mem; s = mem+65536-romptr;
free(d); free(d);
n = read(fd, romptr, s); n = read(fd, romptr, s);
if(n != s) if(n != s)
fprint(2, "tried to read %uld bytes, got %ld bytes\n", s, n); fprint(2, "tried to read %ulld bytes, got %ld bytes\n", s, n);
close(fd); close(fd);
} }
@ -42,6 +42,9 @@ main(int argc, char **argv)
vlong target; vlong target;
target = 1000; target = 1000;
mem = malloc(0x10000);
if(mem == nil)
sysfatal("bad malloc for mem");
ARGBEGIN{ ARGBEGIN{
case 's': case 's':
target = atoll(EARGF(usage())); target = atoll(EARGF(usage()));
@ -50,6 +53,8 @@ main(int argc, char **argv)
usage(); usage();
break; break;
}ARGEND }ARGEND
if(!argc)
usage();
openprog(*argv); openprog(*argv);
rP = 0x34; rP = 0x34;
pc = 0xFFFC; pc = 0xFFFC;

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5
mem.c
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@ -3,6 +3,9 @@
#include "dat.h" #include "dat.h"
#include "fns.h" #include "fns.h"
u8int *mem;
u8int *romptr;
u8int u8int
memread(u16int a) memread(u16int a)
{ {
@ -12,6 +15,6 @@ memread(u16int a)
void void
memwrite(u16int a, u8int v) memwrite(u16int a, u8int v)
{ {
if(a < romptr) if((void*)a < romptr)
mem[a] = v; mem[a] = v;
} }

10
mkfile
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@ -3,15 +3,9 @@
BIN=/$objtype/bin BIN=/$objtype/bin
TARG=scemu TARG=scemu
OFILES=scemu.$O OFILES=main.$O cpu.$O mem.$O
UPDATE=mkfile prog.s ${OFILES:%.$O=%.c} UPDATE=mkfile prog.s ${OFILES:%.$O=%.c}
default:V: $O.out a.out default:V: $O.out
</sys/src/cmd/mkone </sys/src/cmd/mkone
a.out: prog.s
vasm -Fbin -dotdir prog.s
clean:
rm -f a.out [$OS].out *.[$OS]

11
test.s Normal file
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@ -0,0 +1,11 @@
.org $ff00
reset:
lda #'\'
sta $7000
loop:
ror
jmp loop
.org $fffa
.word reset
.word reset
.word reset