From 2ce21e092161fcc41fa51b365aeb4dd071d7e949 Mon Sep 17 00:00:00 2001
From: Paul Duncan <pabs@pablotron.org>
Date: Wed, 20 Jun 2018 18:29:22 -0400
Subject: add gb.h, add gb_init(), gb_get_rgb_frame(), disable bios

---
 ops.yaml | 80 ++++++++++++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 58 insertions(+), 22 deletions(-)

(limited to 'ops.yaml')

diff --git a/ops.yaml b/ops.yaml
index f08a64a..158b6df 100644
--- a/ops.yaml
+++ b/ops.yaml
@@ -7517,8 +7517,9 @@ ops:
         set_rb(ctx, RB_A, 7);
 templates:
   main: |
-    #include <stdint.h>
-    #include <stdbool.h>
+    #include <string.h>   // memset()
+    #include <stdint.h>   // uint8_t ,etc
+    #include <stdbool.h>  // bool
     #include "gb.h"
 
     #define UNUSED(a) ((void) (a))
@@ -7686,6 +7687,10 @@ templates:
     ) {
       switch (addr & 0xF000) {
       case 0x0000:
+      case 0x1000:
+      case 0x2000:
+      case 0x3000:
+        #if 0
         // bios memory (maybe)
         if (ctx->mmu.in_bios) {
           if (addr < 0x100) {
@@ -7694,12 +7699,8 @@ templates:
             ctx->mmu.in_bios = false;
           }
         }
+        #endif /* 0 */
 
-        // return ROM0 (16k, always mapped)
-        return ctx->mmu.rom[addr];
-      case 0x1000:
-      case 0x2000:
-      case 0x3000:
         // ROM0 (16k, always mapped)
         return ctx->mmu.rom[addr];
       case 0x4000:
@@ -7817,6 +7818,10 @@ templates:
     ) {
       switch (addr & 0xF000) {
       case 0x0000:
+      case 0x1000:
+      case 0x2000:
+      case 0x3000:
+        #if 0
         // bios memory (maybe)
         if (ctx->mmu.in_bios) {
           if (addr < 0x100) {
@@ -7825,12 +7830,8 @@ templates:
             ctx->mmu.in_bios = false;
           }
         }
+        #endif /* 0 */
 
-        // return ROM0 (16k, always mapped)
-        return ctx->mmu.rom[addr];
-      case 0x1000:
-      case 0x2000:
-      case 0x3000:
         // ROM0 (16k, always mapped)
         return ctx->mmu.rom[addr];
       case 0x4000:
@@ -9609,19 +9610,15 @@ templates:
     void
     gb_set_buttons(
       gb_t * const ctx,
-      const uint8_t btn,
-      const bool set
+      const uint8_t btns
     ) {
-      if (set) {
+      if (ctx->mmu.btns != btns) {
         // set buttons
-        ctx->mmu.btns |= btn;
-      } else {
-        // clear buttons
-        ctx->mmu.btns &= ~btn;
-      }
+        ctx->mmu.btns = btns;
 
-      // trigger p1 interrupt
-      mmu_wb(ctx, PORT_IF, mmu_rb(ctx, PORT_IF) & (1 << 4));
+        // trigger p1 interrupt
+        mmu_wb(ctx, PORT_IF, mmu_rb(ctx, PORT_IF) & (1 << 4));
+      }
     }
 
     void
@@ -9634,3 +9631,42 @@ templates:
         gb_step(ctx);
       }
     }
+
+    const uint8_t *
+    gb_get_rgb_frame(
+      const gb_t * const ctx
+    ) {
+      return ctx->gpu.rgb;
+    }
+
+    static void
+    cpu_init(
+      gb_t * const ctx
+    ) {
+      // set cpu state
+      ctx->cpu.state = STATE_RUN;
+
+      // init cpu registers
+      // (src: TCAGBD.pdf, 3.2)
+      ctx->cpu.rs[RW_AF] = 0x01B0;
+      ctx->cpu.rs[RW_BC] = 0x0013;
+      ctx->cpu.rs[RW_DE] = 0x00D8;
+      ctx->cpu.rs[RW_HL] = 0x014D;
+      ctx->cpu.rs[RW_SP] = 0xFFFE;
+      ctx->cpu.rs[RW_PC] = 0x0100;
+    }
+
+    void gb_init(
+      gb_t * const ctx,
+      const uint8_t * const rom,
+      const uint32_t rom_size
+    ) {
+      // clear context
+      memset(ctx, 0, sizeof(gb_t));
+
+      cpu_init(ctx);
+
+      // init mmu
+      ctx->mmu.rom = rom;
+      ctx->mmu.rom_size = rom_size;
+    }
-- 
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