1 files changed, 196 insertions, 0 deletions

diff --git a/src/uxn/uxn.c b/src/uxn/uxn.c
new file mode 100644
index 0000000..796a980
--- /dev/null
+++ b/src/uxn/uxn.c
@@ -0,0 +1,196 @@
+#include <stdio.h>
+#include "uxn.h"
+
+/*
+Copyright (u) 2021 Devine Lu Linvega
+
+Permission to use, copy, modify, and distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE.
+*/
+
+#pragma mark - Operations
+
+/* clang-format off */
+void   push8(Stack *s, Uint8 a) { if (s->ptr == 0xff) { s->error = 2; return; } s->dat[s->ptr++] = a; }
+Uint8  pop8_keep(Stack *s) { if (s->kptr == 0) { s->error = 1; return 0; } return s->dat[--s->kptr]; }
+Uint8  pop8_nokeep(Stack *s) { if (s->ptr == 0) { s->error = 1; return 0; } return s->dat[--s->ptr]; }
+static Uint8 (*pop8)(Stack *s);
+void   mempoke8(Uint8 *m, Uint16 a, Uint8 b) { m[a] = b; }
+Uint8  mempeek8(Uint8 *m, Uint16 a) { return m[a]; }
+void   devpoke8(Device *d, Uint8 a, Uint8 b) { d->dat[a & 0xf] = b; d->talk(d, a & 0x0f, 1); }
+Uint8  devpeek8(Device *d, Uint8 a) { d->talk(d, a & 0x0f, 0); return d->dat[a & 0xf];  }
+void   push16(Stack *s, Uint16 a) { push8(s, a >> 8); push8(s, a); }
+Uint16 pop16(Stack *s) { return pop8(s) + (pop8(s) << 8); }
+void   mempoke16(Uint8 *m, Uint16 a, Uint16 b) { mempoke8(m, a, b >> 8); mempoke8(m, a + 1, b); }
+Uint16 mempeek16(Uint8 *m, Uint16 a) { return (mempeek8(m, a) << 8) + mempeek8(m, a + 1); }
+void   devpoke16(Device *d, Uint8 a, Uint16 b) { devpoke8(d, a, b >> 8); devpoke8(d, a + 1, b); }
+Uint16 devpeek16(Device *d, Uint16 a) { return (devpeek8(d, a) << 8) + devpeek8(d, a + 1); }
+/* Stack */
+void op_brk(Uxn *u) { u->ram.ptr = 0; }
+void op_nop(Uxn *u) { (void)u; }
+void op_lit(Uxn *u) { push8(u->src, mempeek8(u->ram.dat, u->ram.ptr++)); }
+void op_pop(Uxn *u) { pop8(u->src); }
+void op_dup(Uxn *u) { Uint8 a = pop8(u->src); push8(u->src, a); push8(u->src, a); }
+void op_swp(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, a); push8(u->src, b); }
+void op_ovr(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b); push8(u->src, a); push8(u->src, b); }
+void op_rot(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src), c = pop8(u->src); push8(u->src, b); push8(u->src, a); push8(u->src, c); }
+/* Logic */
+void op_equ(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b == a); }
+void op_neq(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b != a); }
+void op_gth(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b > a); }
+void op_lth(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b < a); }
+void op_jmp(Uxn *u) { Uint8 a = pop8(u->src); u->ram.ptr += (Sint8)a; }
+void op_jnz(Uxn *u) { Uint8 a = pop8(u->src); if (pop8(u->src)) u->ram.ptr += (Sint8)a; }
+void op_jsr(Uxn *u) { Uint8 a = pop8(u->src); push16(u->dst, u->ram.ptr); u->ram.ptr += (Sint8)a; }
+void op_sth(Uxn *u) { Uint8 a = pop8(u->src); push8(u->dst, a); }
+/* Memory */
+void op_pek(Uxn *u) { Uint8 a = pop8(u->src); push8(u->src, mempeek8(u->ram.dat, a)); }
+void op_pok(Uxn *u) { Uint8 a = pop8(u->src); Uint8 b = pop8(u->src); mempoke8(u->ram.dat, a, b); }
+void op_ldr(Uxn *u) { Uint8 a = pop8(u->src); push8(u->src, mempeek8(u->ram.dat, u->ram.ptr + (Sint8)a)); }
+void op_str(Uxn *u) { Uint8 a = pop8(u->src); Uint8 b = pop8(u->src); mempoke8(u->ram.dat, u->ram.ptr + (Sint8)a, b); }
+void op_lda(Uxn *u) { Uint16 a = pop16(u->src); push8(u->src, mempeek8(u->ram.dat, a)); }
+void op_sta(Uxn *u) { Uint16 a = pop16(u->src); Uint8 b = pop8(u->src); mempoke8(u->ram.dat, a, b); }
+void op_dei(Uxn *u) { Uint8 a = pop8(u->src); push8(u->src, devpeek8(&u->dev[a >> 4], a)); }
+void op_deo(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); devpoke8(&u->dev[a >> 4], a, b); }
+/* Arithmetic */
+void op_add(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b + a); }
+void op_sub(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b - a); }
+void op_mul(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b * a); }
+void op_div(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b / a); }
+void op_and(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b & a); }
+void op_ora(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b | a); }
+void op_eor(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b ^ a); }
+void op_sft(Uxn *u) { Uint8 a = pop8(u->src), b = pop8(u->src); push8(u->src, b >> (a & 0x07) << ((a & 0x70) >> 4)); }
+/* Stack */
+void op_lit16(Uxn *u) { push16(u->src, mempeek16(u->ram.dat, u->ram.ptr++)); u->ram.ptr++; }
+void op_pop16(Uxn *u) { pop16(u->src); }
+void op_dup16(Uxn *u) { Uint16 a = pop16(u->src); push16(u->src, a); push16(u->src, a); }
+void op_swp16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, a); push16(u->src, b); }
+void op_ovr16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, b); push16(u->src, a); push16(u->src, b); }
+void op_rot16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src), c = pop16(u->src); push16(u->src, b); push16(u->src, a); push16(u->src, c); }
+/* Logic(16-bits) */
+void op_equ16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push8(u->src, b == a); }
+void op_neq16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push8(u->src, b != a); }
+void op_gth16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push8(u->src, b > a); }
+void op_lth16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push8(u->src, b < a); }
+void op_jmp16(Uxn *u) { u->ram.ptr = pop16(u->src); }
+void op_jnz16(Uxn *u) { Uint16 a = pop16(u->src); if (pop8(u->src)) u->ram.ptr = a; }
+void op_jsr16(Uxn *u) { push16(u->dst, u->ram.ptr); u->ram.ptr = pop16(u->src); }
+void op_sth16(Uxn *u) { Uint16 a = pop16(u->src); push16(u->dst, a); }
+/* Memory(16-bits) */
+void op_pek16(Uxn *u) { Uint8 a = pop8(u->src); push16(u->src, mempeek16(u->ram.dat, a)); }
+void op_pok16(Uxn *u) { Uint8 a = pop8(u->src); Uint16 b = pop16(u->src); mempoke16(u->ram.dat, a, b); }
+void op_ldr16(Uxn *u) { Uint8 a = pop8(u->src); push16(u->src, mempeek16(u->ram.dat, u->ram.ptr + (Sint8)a)); }
+void op_str16(Uxn *u) { Uint8 a = pop8(u->src); Uint16 b = pop16(u->src); mempoke16(u->ram.dat, u->ram.ptr + (Sint8)a, b); }
+void op_lda16(Uxn *u) { Uint16 a = pop16(u->src); push16(u->src, mempeek16(u->ram.dat, a)); }
+void op_sta16(Uxn *u) { Uint16 a = pop16(u->src); Uint16 b = pop16(u->src); mempoke16(u->ram.dat, a, b); }
+void op_dei16(Uxn *u) { Uint8 a = pop8(u->src); push16(u->src, devpeek16(&u->dev[a >> 4], a)); }
+void op_deo16(Uxn *u) { Uint8 a = pop8(u->src); Uint16 b = pop16(u->src); devpoke16(&u->dev[a >> 4], a, b); }
+/* Arithmetic(16-bits) */
+void op_add16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, b + a); }
+void op_sub16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, b - a); }
+void op_mul16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, b * a); }
+void op_div16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, b / a); }
+void op_and16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, b & a); }
+void op_ora16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, b | a); }
+void op_eor16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, b ^ a); }
+void op_sft16(Uxn *u) { Uint16 a = pop16(u->src), b = pop16(u->src); push16(u->src, b >> (a & 0x000f) << ((a & 0x00f0) >> 4)); }
+
+void (*ops[])(Uxn *u) = {
+        op_brk, op_lit, op_nop, op_pop, op_dup, op_swp, op_ovr, op_rot,
+        op_equ, op_neq, op_gth, op_lth, op_jmp, op_jnz, op_jsr, op_sth,
+        op_pek, op_pok, op_ldr, op_str, op_lda, op_sta, op_dei, op_deo,
+        op_add, op_sub, op_mul, op_div, op_and, op_ora, op_eor, op_sft,
+        /* 16-bit */
+        op_brk,   op_lit16, op_nop,   op_pop16, op_dup16, op_swp16, op_ovr16, op_rot16,
+        op_equ16, op_neq16, op_gth16, op_lth16, op_jmp16, op_jnz16, op_jsr16, op_sth16,
+        op_pek16, op_pok16, op_ldr16, op_str16, op_lda16, op_sta16, op_dei16, op_deo16,
+        op_add16, op_sub16, op_mul16, op_div16, op_and16, op_ora16, op_eor16, op_sft16
+};
+
+/* clang-format on */
+
+#pragma mark - Core
+
+int
+haltuxn(Uxn *u, char *name, int id)
+{
+        txt_printf("Halted: %s#%04x, at 0x%04x\n", name, id, u->ram.ptr);
+        u->ram.ptr = 0;
+        return 0;
+}
+
+void
+opcuxn(Uxn *u, Uint8 instr)
+{
+        Uint8 op = instr & 0x3f, freturn = instr & 0x40, fkeep = instr & 0x80;
+        u->src = freturn ? &u->rst : &u->wst;
+        u->dst = freturn ? &u->wst : &u->rst;
+        if(fkeep) {
+                pop8 = pop8_keep;
+                u->src->kptr = u->src->ptr;
+        } else {
+                pop8 = pop8_nokeep;
+        }
+        (*ops[op])(u);
+}
+
+int
+stepuxn(Uxn *u, Uint8 instr)
+{
+        opcuxn(u, instr);
+        if(u->wst.error)
+                return haltuxn(u, u->wst.error == 1 ? "Working-stack underflow" : "Working-stack overflow", instr);
+        if(u->rst.error)
+                return haltuxn(u, u->rst.error == 1 ? "Return-stack underflow" : "Return-stack overflow", instr);
+        return 1;
+}
+
+int
+evaluxn(Uxn *u, Uint16 vec)
+{
+        u->ram.ptr = vec;
+        u->wst.error = 0;
+        u->rst.error = 0;
+        while(u->ram.ptr)
+                if(!stepuxn(u, u->ram.dat[u->ram.ptr++]))
+                        return 0;
+        return 1;
+}
+
+int
+bootuxn(Uxn *u)
+{
+        size_t i;
+        char *cptr = (char *)u;
+        for(i = 0; i < sizeof(*u); i++)
+                cptr[i] = 0;
+        return 1;
+}
+
+int
+loaduxn(Uxn *u, char *filepath)
+{
+        FILE *f;
+        if(!(f = fopen(filepath, "rb")))
+                return haltuxn(u, "Missing input rom.", 0);
+        fread(u->ram.dat + PAGE_PROGRAM, sizeof(u->ram.dat) - PAGE_PROGRAM, 1, f);
+        txt_printf("Uxn loaded[%s].\n", filepath);
+        return 1;
+}
+
+Device *
+portuxn(Uxn *u, Uint8 id, char *name, void (*talkfn)(Device *d, Uint8 b0, Uint8 w))
+{
+        Device *d = &u->dev[id];
+        d->addr = id * 0x10;
+        d->u = u;
+        d->mem = u->ram.dat;
+        d->talk = talkfn;
+        txt_printf("Device added #%02x: %s, at 0x%04x \n", id, name, d->addr);
+        return d;
+}