oam timings passing.

.vscode/settings.json

@@ -10,6 +10,11 @@
         "xtr1common": "c",
         "chrono": "c",
         "interrupts.h": "c",
-        "cmath": "c"
+        "cmath": "c",
+        "algorithm": "c",
+        "functional": "c",
+        "optional": "c",
+        "system_error": "c",
+        "xutility": "c"
     }
 }

include/dma.h

@@ -6,8 +6,10 @@ typedef struct {
     bool active;
     u8 byte;
     u8 value;
+    u8 value_buffer;
     u8 start_delay;
     bool transferring;
+    bool dma_waiting;
 } dma_context;
 
 typedef struct {

lib/dma.c

@@ -8,23 +8,31 @@
 static dma_context ctx;
 
 void dma_start(u8 start) {
+    ctx.start_delay = 1;
+    ctx.value_buffer = start;
+    ctx.dma_waiting = true;
+}
+
+void dma_begin() {
     ctx.active = true;
     ctx.byte = 0;
-    ctx.start_delay = 2;
+    ctx.value = ctx.value_buffer;
-    ctx.value = start;
+    ctx.dma_waiting = false;
-    ctx.transferring = false;
 }
 
 void dma_tick() {
     ctx.transferring = false;
+
+    if (ctx.start_delay) {
+        ctx.start_delay--;
+    } else if(ctx.dma_waiting) {
+        dma_begin();
+    }
+
     if (!ctx.active) {
         return;
     }
 
-    if (ctx.start_delay) {
-        ctx.start_delay--;
-        return;
-    }
     ctx.transferring = true;
     u8 data = 0;
     u16 addr = (ctx.value << 8) | ctx.byte;
@@ -45,7 +53,7 @@ void dma_tick() {
 }
 
 bool dma_transferring() {
-    return ctx.transferring && ctx.active;
+    return ctx.transferring;// && ctx.active;
 }
 
 void dma_save_state(dma_state* state) {