[dbg] Add endian order operations

src/emu/endian.rs

@@ -1,15 +0,0 @@
-
-/// read a 24bit endian value, and place it in a u32 num
-pub fn read_big_endian_tribyte(input:&[u8;3]) ->u32{
-    todo!()
-}
-
-pub fn read_big_endian_byte_array(input:&[u8]) ->u32{
-    todo!()
-}
-
-
-/// Get 24 bit big endian slice
-pub fn get_big_endian(input:u32)->[u8;3]{
-    todo!()
-}

src/emu/iomem.rs

@@ -1,32 +1,42 @@
 
 use crate::emu::mmu::Memory;
+use crate::misc::endian::MemoryOperations;
 
 #[derive(Debug, Copy, Clone)]
 pub struct MemoryMappedIO {
-    keyboard_bits: [u8;2],
+    //FIXME use a keyboard
+    keyboard_bytes: [u8;2],
     program_counter: [u8; 3],
+    //FIXME use a device
     pixel_reg: u8,
+    //FIXME use a device
     audio_sample_address_base: [u8; 2],
 }
 
 impl MemoryMappedIO {
     pub fn new() -> MemoryMappedIO {
         MemoryMappedIO {
-            keyboard_bits: [0,0],
+            keyboard_bytes: [0,0],
             program_counter: [0, 0, 0],
             pixel_reg: 0,
             audio_sample_address_base: [0, 0],
         }
     }
 }
+// 2 byte keyboard bits
 
 const KEYBOARD_BIT_START: u32 = 0;
 const KEYBOARD_BIT_END: u32 = 1;
+
+// 3 bytes PC
 const PC_START_ADDR: u32 = 2;
 const PC_LEN: u32 = 3;
 const PC_END_ADDR: u32 = PC_START_ADDR + PC_LEN - 1;
 
+// 1 byte pixel base reg
 const PIXEL_BASE: u32 = 5;
+
+// 2 byte audio sample base reg
 const AUDIO_SAMPLE_BASE_START: u32 = 6;
 const AUDIO_SAMPLE_BASE_LEN: u32 = 2;
 const AUDIO_SAMPLE_BASE_END: u32 = AUDIO_SAMPLE_BASE_START + AUDIO_SAMPLE_BASE_LEN - 1;
@@ -36,13 +46,15 @@ impl Memory for MemoryMappedIO {
         match address {
             KEYBOARD_BIT_START..=KEYBOARD_BIT_END => {
                 let addr_usize = address as usize;
-                log::trace!("Fetching keyboard bits segment {}",addr_usize);
-                self.keyboard_bits[addr_usize]
+                let keyboard_byte = self.keyboard_bytes[addr_usize];
+                log::trace!("Fetching keyboard({}) byte segment {} -> {}",MemoryOperations::read_big_endian_u16(&self.keyboard_bytes),address,keyboard_byte);
+                keyboard_byte
             },
             PC_START_ADDR..=PC_END_ADDR => {
                 let pc_index = (address - PC_START_ADDR) as usize;
-                log::trace!("Fetching PC {:?} bit segment {}",self.program_counter,pc_index);
-                self.program_counter[pc_index]
+                let pc_byte = self.program_counter[pc_index];
+                log::trace!("Fetching PC({}) byte segment {} -> {}",MemoryOperations::read_big_endian_u24(&self.program_counter),pc_index,pc_byte);
+                pc_byte
             },
             PIXEL_BASE => {
                 log::trace!("Fetching pixel base reg {}",self.pixel_reg);

src/emu/mmu.rs

@@ -1,8 +1,10 @@
 use crate::emu::iomem::MemoryMappedIO;
 use crate::emu::mem::RamMemory;
 
+// 8 bytes that are memory mapped i/o
 pub const MMAPPEDIO_END: u32 = RAM_MEM_START-1;
 pub const RAM_MEM_START:u32 = 8;
+/// Last index of ram
 pub const RAM_MEM_END: u32 = 2<<24 - 1;
 
 ///

src/emu/mod.rs

@@ -1,5 +1,4 @@
 pub mod cpu;
 pub mod mmu;
 pub mod mem;
-mod endian;
 pub mod iomem;

src/main.rs

@@ -5,6 +5,7 @@ use crate::emu::mmu::{Memory, MappedMemory};
 
 mod emu;
 mod args;
+mod misc;
 
 fn main() {
     SimpleLogger::new().init().unwrap();

src/misc/endian.rs

@@ -0,0 +1,18 @@
+use byteorder::{BigEndian, ByteOrder};
+
+pub struct MemoryOperations();
+
+impl MemoryOperations {
+    /// read a 24bit endian value, and place it in a u32 num
+    pub fn read_big_endian_u24(input: &[u8; 3]) -> u32 {
+        BigEndian::read_u24(input)
+    }
+
+    pub fn read_big_endian_u16(input: &[u8; 2]) -> u16 {
+        BigEndian::read_u16(input)
+    }
+    /// Write 24-bit endian number into slice
+    pub fn write_big_endian_u24(input: u32, output_slice: &mut [u8; 3]) {
+        BigEndian::write_u24(output_slice, input);
+    }
+}

src/misc/mod.rs

@@ -0,0 +1 @@
+pub mod endian;