From 4bec0d073f8269f57dd9d2d20926dc3ebbf72598 Mon Sep 17 00:00:00 2001
From: Corwin <corwin@kuiper.dev>
Date: Mon, 14 Mar 2022 23:55:14 +0000
Subject: [PATCH] The poor profiler

---
 agb/examples/sprites.rs | 14 ++++++++++++++
 agb/interrupt_handler.s | 12 ++++++++++++
 agb/src/lib.rs          |  8 ++++++++
 agb/src/timer.rs        |  5 +++++
 4 files changed, 39 insertions(+)

diff --git a/agb/examples/sprites.rs b/agb/examples/sprites.rs
index badda4a8..afb31424 100644
--- a/agb/examples/sprites.rs
+++ b/agb/examples/sprites.rs
@@ -5,6 +5,7 @@ extern crate alloc;
 
 use agb::display::object::{Graphics, ObjectController, Sprite, TagMap};
 use alloc::vec::Vec;
+use bare_metal::CriticalSection;
 
 const GRAPHICS: &Graphics = agb::include_aseprite!(
     "../examples/the-purple-night/gfx/objects.aseprite",
@@ -100,6 +101,19 @@ fn all_tags(gfx: &ObjectController) {
 fn main(mut gba: agb::Gba) -> ! {
     let gfx = gba.display.object.get();
 
+    let timers = gba.timers.timers();
+    let mut my_timer = timers.timer0;
+    my_timer.set_interrupt(true);
+    my_timer.set_overflow_amount(10000);
+    my_timer.set_enabled(true);
+
+    agb::add_interrupt_handler!(
+        agb::interrupt::Interrupt::Timer0,
+        |_key: &CriticalSection| {
+            agb::println!("{:#010x}", agb::get_program_counter_before_interrupt());
+        }
+    );
+
     loop {
         all_tags(&gfx);
         all_sprites(&gfx);
diff --git a/agb/interrupt_handler.s b/agb/interrupt_handler.s
index a68814e8..8803ca4d 100644
--- a/agb/interrupt_handler.s
+++ b/agb/interrupt_handler.s
@@ -1,3 +1,4 @@
+
 @ An interrupt handler that simply acknowledges all interrupts
     .arm
     .global InterruptHandler
@@ -14,6 +15,10 @@ InterruptHandler:
     ldrh r3, [r2, #2] @ load 16 bit interrupt request to r3
     and r0, r1, r3 @ interrupts both enabled and requested
 
+    ldr r1, [sp, #20]
+    ldr r3, =agb_rs__program_counter
+    str r1, [r3]
+
     @ change to system mode
     mrs r1, cpsr
     orr r1, r1, #0xD
@@ -43,3 +48,10 @@ InterruptHandler:
 
     bx lr @ return to bios
 .pool
+
+
+.section .iwram
+    .global agb_rs__program_counter
+    .balign 4
+agb_rs__program_counter:
+    .word 0
diff --git a/agb/src/lib.rs b/agb/src/lib.rs
index 9d946b69..a4290c96 100644
--- a/agb/src/lib.rs
+++ b/agb/src/lib.rs
@@ -407,3 +407,11 @@ mod test {
         }
     }
 }
+
+#[inline(never)]
+pub fn get_program_counter_before_interrupt() -> u32 {
+    extern "C" {
+        static mut agb_rs__program_counter: u32;
+    }
+    unsafe { agb_rs__program_counter }
+}
diff --git a/agb/src/timer.rs b/agb/src/timer.rs
index f5ebcb7f..13ae810c 100644
--- a/agb/src/timer.rs
+++ b/agb/src/timer.rs
@@ -90,6 +90,11 @@ impl Timer {
         self.control_register().set_bits(bit, 1, 2);
     }
 
+    pub fn set_interrupt(&mut self, interrupt: bool) {
+        let bit = interrupt as u16;
+        self.control_register().set_bits(bit, 1, 6);
+    }
+
     fn data_register(&self) -> MemoryMapped<u16> {
         timer_data(self.get_timer_number())
     }