From 89cc9423bd7afb42a624fa796e29ab012fdc9714 Mon Sep 17 00:00:00 2001
From: Quentin Legot <legotquentin@gmail.com>
Date: Wed, 18 Jan 2023 15:03:58 +0100
Subject: [PATCH] Fix read_memory and implemented write_memory

---
 src/simulator/machine.rs | 41 +++++++++++++++++++++-------------------
 1 file changed, 22 insertions(+), 19 deletions(-)

diff --git a/src/simulator/machine.rs b/src/simulator/machine.rs
index 672db4e..a94492d 100644
--- a/src/simulator/machine.rs
+++ b/src/simulator/machine.rs
@@ -37,43 +37,45 @@ impl Machine {
 
 	/// Read from main memory of the machine
 	///
+	/// `panic!` when size is not 1, 2, 4 or 8
+	/// 
 	/// ### Parameters
 	///
 	/// - **machine** which contains the main memory
 	/// - **size** the number of bytes to read (1, 2, 4, 8)
 	/// - **address** in the memory to read
 	pub fn read_memory(machine : &mut Machine, size : i32, address : usize) -> u64 {
-		if size != 1 && size != 2 && size != 4 && size != 8 {
+		if ![1, 2, 4, 8].contains(&size) {
 			panic!("ERROR read_memory : wrong size parameter {}, must be (1, 2, 4 or 8)", size);
 		}
 
-		let mut ret : u64 = machine.main_memory[address] as u64;
-		if size == 2 || size == 4 || size == 8 {
+		let mut ret: u64 = 0;
+		for i in 0..size {
 			ret <<= 8;
-			ret += machine.main_memory[address + 1] as u64;
-		}
-		if size == 4 || size == 8 {
-			ret <<= 8;
-			ret += machine.main_memory[address + 2] as u64;
-		}
-		if size == 8 {
-			ret <<= 8;
-			ret += machine.main_memory[address + 3] as u64;
+			ret += machine.main_memory[address + i as usize] as u64;
 		}
 		ret
 	}
 
 	/// Write to the main memory of the machine
 	/// 
-	/// **machine** contains the memory
-	/// **size** the number of bytes to write (1, 2, 4 or 8)
-	/// **address** the address to write to
-	/// **value** data to be written
-	pub fn write_memory(machine: &mut Machine, size: i32, address: usize, value: i64) {
-		if ![1, 2, 3, 4].contains(&size) {
+	/// `panic!` when size is not 1, 2, 4 or 8
+	/// 
+	/// ### Parameters
+	/// 
+	/// - **machine** contains the memory
+	/// - **size** the number of bytes to write (1, 2, 4 or 8)
+	/// - **address** the address to write to
+	/// - **value** data to be written
+	pub fn write_memory(machine: &mut Machine, size: i32, address: usize, value: u64) {
+		if ![1, 2, 4, 8].contains(&size) {
 			panic!("ERROR write_memory: WRONG `size` PARAMETER ({}), must be 1, 2, 4 or 8", size)
 		}
-		todo!("Write memory not implemented yet");
+		let map: [u64; 8] = [0xff000000_00000000, 0x00ff0000_00000000, 0x0000ff00_00000000, 0x000000ff_00000000, 
+			0x00000000_ff00000000, 0x00000000_00ff0000, 0x00000000_0000ff00, 0x00000000_000000ff];
+		for i in 0..size as usize {
+			machine.main_memory[address + i as usize] = (value & map[i]) as u8;
+		}
 	}
 
 	/// Execute the instructions table of a machine putted in param
@@ -209,6 +211,7 @@ impl Machine {
 			RISCV_ST => {
 				match inst.funct3 {
 					RISCV_ST_STB => {
+						
 						todo!("Write memory here");
 					},
 					RISCV_ST_STH => {