From bc6f3e6f8007b3ce7555d96a71fcab6d9a3e836d Mon Sep 17 00:00:00 2001
From: Corwin Kuiper <corwin@kuiper.dev>
Date: Sat, 3 Apr 2021 18:37:09 +0100
Subject: [PATCH] add copious amount of comments

---
 interrupt_simple.s | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/interrupt_simple.s b/interrupt_simple.s
index 61df2f3a..0d91381f 100644
--- a/interrupt_simple.s
+++ b/interrupt_simple.s
@@ -3,15 +3,15 @@
     .global InterruptHandlerSimple
     .align
 InterruptHandlerSimple:
-    ldr r2, =0x04000200
-    ldrh r1, [r2]
-    ldrh r3, [r2, #2]
-    and r0, r1, r3
-    strh r0, [r2, #2]
+    ldr r2, =0x04000200 @ interrupt enable register location
+    ldrh r1, [r2] @ load 16 bit interrupt enable to r1
+    ldrh r3, [r2, #2] @ load 16 bit interrupt request to r3
+    and r0, r1, r3 @ interrupts both enabled and requested
+    strh r0, [r2, #2] @ store to interrupt request
 
-    ldr r2, =0x03007FF8
-    ldrh r1, [r2]
-    orr r1, r1, r0
-    strh r1, [r2]
+    ldr r2, =0x03007FF8 @ load bios interrupt request location
+    ldrh r1, [r2] @ load bios interrupt requests
+    orr r1, r1, r0 @ or with enabled and requested interrupts
+    strh r1, [r2] @ acknowlege bios requests
     
-    bx lr
+    bx lr @ return to bios