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This commit is contained in:
neauoire 2021-02-02 09:40:41 -08:00
parent 2cf40a4293
commit 97164124ef
2 changed files with 33 additions and 27 deletions
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2
examples/core.usm
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@ -1,4 +1,4 @@
< core >
01 ADD
01 02 ADD

58
uxn.c
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@ -16,18 +16,24 @@ WITH REGARD TO THIS SOFTWARE.
#define FLAG_CARRY 0x04
#define FLAG_TRAPS 0x08
#define STACK_DEPTH 256
typedef unsigned char Uint8;
typedef unsigned short Uint16;
typedef struct {
Uint8 ptr;
Uint8 dat[256];
} Stack;
typedef struct {
Uint16 ptr;
Uint8 dat[65536];
} Memory;
typedef struct {
Uint8 literal, status;
Uint8 mptr, sptr, rsptr;
Uint8 memory[STACK_DEPTH];
Uint8 stack[STACK_DEPTH];
Uint8 rstack[STACK_DEPTH];
Uint16 counter;
Stack wst, rst;
Memory rom, ram;
} Computer;
Computer cpu;
@ -65,25 +71,25 @@ echo(Uint8 *s, Uint8 len, char *name)
void
spush(Uint8 v)
{
cpu.stack[cpu.sptr++] = v;
cpu.wst.dat[cpu.wst.ptr++] = v;
}
Uint8
spop(void)
{
return cpu.stack[--cpu.sptr];
return cpu.wst.dat[--cpu.wst.ptr];
}
void
rspush(Uint8 v)
{
cpu.rstack[cpu.rsptr++] = v;
cpu.rst.dat[cpu.rst.ptr++] = v;
}
Uint8
rspop(void)
{
return cpu.rstack[--cpu.rsptr];
return cpu.rst.dat[--cpu.rst.ptr];
}
#pragma mark - Operations
@ -91,17 +97,17 @@ rspop(void)
/* clang-format off */
void op_brk() { setflag(FLAG_HALT, 1); }
void op_rts() { cpu.mptr = rspop(); }
void op_lit() { cpu.literal += cpu.memory[cpu.mptr++]; }
void op_rts() { cpu.rom.ptr = rspop(); }
void op_lit() { cpu.literal += cpu.rom.dat[cpu.rom.ptr++]; }
void op_drp() { spop(); }
void op_dup() { spush(cpu.stack[cpu.sptr - 1]); }
void op_dup() { spush(cpu.wst.dat[cpu.wst.ptr - 1]); }
void op_swp() { Uint8 b = spop(), a = spop(); spush(b); spush(a); }
void op_ovr() { spush(cpu.stack[cpu.sptr - 2]); }
void op_ovr() { spush(cpu.wst.dat[cpu.wst.ptr - 2]); }
void op_rot() { Uint8 c = spop(),b = spop(),a = spop(); spush(b); spush(c); spush(a); }
void op_jmp() { cpu.mptr = spop(); }
void op_jsr() { rspush(cpu.mptr); cpu.mptr = spop(); }
void op_jmq() { Uint8 a = spop(); if(getflag(FLAG_ZERO)){ cpu.mptr = a; } setflag(FLAG_ZERO,0); }
void op_jsq() { Uint8 a = spop(); if(getflag(FLAG_ZERO)){ rspush(cpu.mptr); cpu.mptr = a; } setflag(FLAG_ZERO,0); }
void op_jmp() { cpu.rom.ptr = spop(); }
void op_jsr() { rspush(cpu.rom.ptr); cpu.rom.ptr = spop(); }
void op_jmq() { Uint8 a = spop(); if(getflag(FLAG_ZERO)){ cpu.rom.ptr = a; } setflag(FLAG_ZERO,0); }
void op_jsq() { Uint8 a = spop(); if(getflag(FLAG_ZERO)){ rspush(cpu.rom.ptr); cpu.rom.ptr = a; } setflag(FLAG_ZERO,0); }
void op_equ() { setflag(FLAG_ZERO, spop() == spop()); }
void op_neq() { setflag(FLAG_ZERO, spop() != spop()); }
void op_lth() { setflag(FLAG_ZERO, spop() < spop()); }
@ -135,11 +141,12 @@ reset(void)
int i;
cpu.status = 0x00;
cpu.counter = 0x00;
cpu.mptr = 0x00;
cpu.sptr = 0x00;
cpu.rom.ptr = 0x00;
cpu.wst.ptr = 0x00;
cpu.literal = 0x00;
cpu.rst.ptr = 0x00;
for(i = 0; i < 256; i++)
cpu.stack[i] = 0x00;
cpu.wst.dat[i] = 0x00;
}
int
@ -152,20 +159,20 @@ error(char *name)
void
load(FILE *f)
{
fread(cpu.memory, sizeof(cpu.memory), 1, f);
fread(cpu.rom.dat, sizeof(cpu.rom.dat), 1, f);
}
int
eval()
{
Uint8 instr = cpu.memory[cpu.mptr++];
Uint8 instr = cpu.rom.dat[cpu.rom.ptr++];
if(cpu.literal > 0) {
spush(instr);
cpu.literal--;
return 1;
}
if(instr < 24) {
if(cpu.sptr < opr[instr][0])
if(cpu.wst.ptr < opr[instr][0])
return error("Stack underflow");
/* TODO stack overflow */
(*ops[instr])();
@ -203,7 +210,6 @@ main(int argc, char *argv[])
load(f);
run();
/* print result */
echo(cpu.stack, 0x40, "stack");
echo(cpu.memory, 0x40, "memory");
echo(cpu.wst.dat, 0x40, "stack");
return 0;
}