misc oam/vram function fixes

2 files changed, 31 insertions, 41 deletions

diff --git a/gb.h b/gb.h
index 358c1f2..2be0806 100644
--- a/gb.h
+++ b/gb.h
@@ -56,7 +56,7 @@ struct gb_t_ {
     uint8_t eram[0x10000]; // external ram (banked, up to 64k)
     uint8_t vram[0x2000]; // vram (8k)
     uint8_t oam[0xA0]; // oam (160 bytes)
-    uint8_t zram[0x7F]; // zram (128 bytes)
+    uint8_t zram[0x80]; // zram (128 bytes)
 
     // rom (at least 32k)
     const uint8_t *rom;
diff --git a/ops.yaml b/ops.yaml
index 3088ea2..d11350e 100644
--- a/ops.yaml
+++ b/ops.yaml
@@ -8833,9 +8833,10 @@ templates:
       const gb_t * const ctx,
       const uint16_t addr
     ) {
-      if (gpu_is_active(ctx) && gpu_get_mode(ctx) == GPU_MODE_VRAM) {
+      switch (gpu_get_mode(ctx)) {
+      case GPU_MODE_VRAM:
         return 0xFF;
-      } else {
+      default:
         // return vram (8k)
         return ctx->mmu.vram[addr & 0x1FFF];
       }
@@ -8846,18 +8847,14 @@ templates:
       const gb_t * const ctx,
       const uint16_t addr
     ) {
-      if (gpu_is_active(ctx)) {
-        switch (gpu_get_mode(ctx)) {
-        case GPU_MODE_HBLANK:
-        case GPU_MODE_VBLANK:
-          // oam memory (160 bytes):
-          return ctx->mmu.oam[addr & 0xFF];
-        default:
-          return 0;
-        }
-      } else {
+      // NOTE: gpu_get_mode() returns VBLANK if gpu is inactive
+      switch (gpu_get_mode(ctx)) {
+      case GPU_MODE_HBLANK:
+      case GPU_MODE_VBLANK:
         // oam memory (160 bytes):
-        return ctx->mmu.oam[addr & 0xFF];
+        return ctx->mmu.oam[addr - 0xFE00];
+      default:
+        return 0;
       }
     }
 
@@ -8971,21 +8968,15 @@ templates:
       const uint16_t addr,
       const uint8_t val
     ) {
-      if (gpu_is_active(ctx)) {
-        switch (gpu_get_mode(ctx)) {
-        case GPU_MODE_HBLANK:
-        case GPU_MODE_VBLANK:
-        case GPU_MODE_OAM:
-          // vram (8k)
-          ctx->mmu.vram[addr & 0x1FFF] = val;
-          break;
-        default:
-          // do nothing
-          break;
-        }
-      } else {
-        // vram (8k)
+      // NOTE: gpu_get_mode() returns VBLANK if lcd is inactive
+      switch (gpu_get_mode(ctx)) {
+      case GPU_MODE_VRAM:
+        // do nothing
+        break;
+      default:
+        // write to vram (8k)
         ctx->mmu.vram[addr & 0x1FFF] = val;
+        break;
       }
     }
 
@@ -8995,21 +8986,20 @@ templates:
       const uint16_t addr,
       const uint8_t val
     ) {
-      if (gpu_is_active(ctx)) {
-        switch (gpu_get_mode(ctx) & 0x3) {
-        case GPU_MODE_HBLANK:
-        case GPU_MODE_VBLANK:
-          // oam memory (160 bytes):
-          ctx->mmu.oam[addr & 0xFF] = val;
+      // NOTE: gpu_get_mode() returns VBLANK if lcd is inactive
+      switch (gpu_get_mode(ctx) & 0x3) {
+      case GPU_MODE_HBLANK:
+      case GPU_MODE_VBLANK:
+        // oam memory (160 bytes):
+        ctx->mmu.oam[addr - 0xFE00] = val;
 
-          // invalidate oam cache
-          ctx->gpu.oam_dirty = true;
+        // invalidate oam cache
+        ctx->gpu.oam_dirty = true;
 
-          break;
-        default:
-          // do nothing
-          break;
-        }
+        break;
+      default:
+        // do nothing
+        break;
       }
     }