From d6fb3df93fa0089834a484386ce3e31ff199720a Mon Sep 17 00:00:00 2001
From: pcasaretto <pcasaretto@gmail.com>
Date: Mon, 8 Apr 2024 22:48:51 -0300
Subject: [PATCH] one more load instruction

---
 src/instructions/ld.rs  | 17 +++++++++++++++++
 src/instructions/mod.rs |  1 +
 2 files changed, 18 insertions(+)

diff --git a/src/instructions/ld.rs b/src/instructions/ld.rs
index f4f36ff..7f6fb65 100644
--- a/src/instructions/ld.rs
+++ b/src/instructions/ld.rs
@@ -57,6 +57,14 @@ pub fn ld_d8_r(target: RegisterTarget) -> impl Fn(&mut CPU) {
     }
 }
 
+pub fn ld_a_mem_at_d8() -> impl Fn(&mut CPU) {
+    move |cpu: &mut CPU| {
+        let addr = 0xFF00 + cpu.read_next_byte() as u16;
+        let value = cpu.registers.get_u8(RegisterTarget::A);
+        cpu.bus.write_byte(addr, value);
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -138,4 +146,13 @@ mod tests {
         ld_d8_mem_at_r16(Register16bTarget::HL)(&mut cpu);
         assert_eq!(cpu.bus.memory[0x1000], 0x34);
     }
+
+    #[test]
+    fn test_ld_a_mem_at_d8() {
+        let mut cpu = CPU::default();
+        cpu.bus.memory[0] = 0x34;
+        cpu.registers.set_u8(RegisterTarget::A, 0x42);
+        ld_a_mem_at_d8()(&mut cpu);
+        assert_eq!(cpu.bus.read_byte(0xFF34), 0x42);
+    }
 }
diff --git a/src/instructions/mod.rs b/src/instructions/mod.rs
index d8db729..bcf8c5b 100644
--- a/src/instructions/mod.rs
+++ b/src/instructions/mod.rs
@@ -143,6 +143,7 @@ pub fn from_byte(byte: u8) -> Box<dyn Fn(&mut CPU)> {
 
         0xD6 => Box::new(sub::sub_d8()),
 
+        0xE0 => Box::new(ld::ld_a_mem_at_d8()),
         0xEA => Box::new(ld::ld_r_mem_at_d16(RegisterTarget::A)),
 
         0xF3 => Box::new(int::di()),