feat: Add the minimal basic implementation

.gitignore

@@ -1,14 +1,10 @@
-# Generated by Cargo
-# will have compiled files and executables
-debug/
-target/
-
-# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
-# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
-Cargo.lock
-
 # These are backup files generated by rustfmt
 **/*.rs.bk
 
 # MSVC Windows builds of rustc generate these, which store debugging information
 *.pdb
+
+
+# Added by cargo
+
+/target

Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "emurv"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

src/cpu.rs

@@ -0,0 +1,29 @@
+use crate::memory;
+
+pub struct CPU {
+    // integer registers
+    regs: [u64; 32],
+    pc: u64,
+    bus: BUS,
+}
+
+pub struct BUS {}
+
+const DEFAULT_RSTVEC: u64 = 0x00001000;
+
+impl CPU {
+    fn new() -> Self {
+        let mut cpu: CPU = CPU {
+            regs: [0; 32],
+            pc: memory::MEMORY_BASE,
+            bus: BUS {},
+        };
+        (cpu).regs[2] = memory::MEMORY_BASE + memory::MEMORY_SIZE; // Set stack pointer
+        (cpu).pc = memory::MEMORY_BASE;
+        return cpu;
+    }
+
+    fn fetch() {}
+
+    fn execute() {}
+}

src/main.rs

@@ -0,0 +1,6 @@
+pub mod cpu;
+pub mod memory;
+
+fn main() {
+    println!("Hello, world!");
+}

src/memory.rs

@@ -0,0 +1,83 @@
+pub const MEMORY_BASE: u64 = 0x80000000; // defined in QEMU
+pub const MEMORY_SIZE: u64 = 1024 * 1024 * 1;
+
+pub struct MEMORY {
+    mem: [u8; MEMORY_SIZE as usize],
+}
+
+impl MEMORY {
+    fn load(self, addr: u64, size: u64) -> u64 {
+        match size {
+            8 => return self.load8(addr),
+            16 => return self.load16(addr),
+            32 => return self.load32(addr),
+            64 => return self.load64(addr),
+            _ => panic!("wrong load size"),
+        }
+    }
+    fn store(&mut self, addr: u64, size: u64, value: u64) {
+        match size {
+            8 => self.store8(addr, value),
+            16 => self.store16(addr, value),
+            32 => self.store32(addr, value),
+            64 => self.store64(addr, value),
+            _ => panic!("wrong store size"),
+        }
+    }
+
+    // load funcs
+    fn load8(self, addr: u64) -> u64 {
+        let index = (addr - MEMORY_BASE) as usize;
+        return self.mem[index] as u64;
+    }
+    fn load16(self, addr: u64) -> u64 {
+        let index = (addr - MEMORY_BASE) as usize;
+        return self.mem[index] as u64 | ((self.mem[index + 1] as u64) << 8);
+    }
+    fn load32(self, addr: u64) -> u64 {
+        let index = (addr - MEMORY_BASE) as usize;
+        return self.mem[index] as u64
+            | ((self.mem[index + 1] as u64) << 8)
+            | ((self.mem[index + 2] as u64) << 16)
+            | ((self.mem[index + 3] as u64) << 24);
+    }
+    fn load64(self, addr: u64) -> u64 {
+        let index = (addr - MEMORY_BASE) as usize;
+        return self.mem[index] as u64
+            | ((self.mem[index + 1] as u64) << 8)
+            | ((self.mem[index + 2] as u64) << 16)
+            | ((self.mem[index + 3] as u64) << 24)
+            | ((self.mem[index + 4] as u64) << 32)
+            | ((self.mem[index + 5] as u64) << 40)
+            | ((self.mem[index + 6] as u64) << 48)
+            | ((self.mem[index + 7] as u64) << 56);
+    }
+
+    // store funcs
+    fn store8(&mut self, addr: u64, value: u64) {
+        let index = (addr - MEMORY_BASE) as usize;
+        self.mem[index] = (value & (std::u8::MAX as u64)) as u8;
+    }
+    fn store16(&mut self, addr: u64, value: u64) {
+        let index = (addr - MEMORY_BASE) as usize;
+        self.mem[index] = (value & (std::u8::MAX as u64)) as u8;
+        self.mem[index + 1] = ((value >> 8) & (std::u8::MAX as u64)) as u8;
+    }
+    fn store32(&mut self, addr: u64, value: u64) {
+        let index = (addr - MEMORY_BASE) as usize;
+        self.mem[index] = (value & (std::u8::MAX as u64)) as u8;
+        self.mem[index + 1] = ((value >> 8) & (std::u8::MAX as u64)) as u8;
+        self.mem[index + 2] = ((value >> 16) & (std::u8::MAX as u64)) as u8;
+    }
+    fn store64(&mut self, addr: u64, value: u64) {
+        let index = (addr - MEMORY_BASE) as usize;
+        self.mem[index] = (value & (std::u8::MAX as u64)) as u8;
+        self.mem[index + 1] = ((value >> 8) & (std::u8::MAX as u64)) as u8;
+        self.mem[index + 2] = ((value >> 16) & (std::u8::MAX as u64)) as u8;
+        self.mem[index + 3] = ((value >> 24) & (std::u8::MAX as u64)) as u8;
+        self.mem[index + 4] = ((value >> 32) & (std::u8::MAX as u64)) as u8;
+        self.mem[index + 5] = ((value >> 40) & (std::u8::MAX as u64)) as u8;
+        self.mem[index + 6] = ((value >> 48) & (std::u8::MAX as u64)) as u8;
+        self.mem[index + 7] = ((value >> 56) & (std::u8::MAX as u64)) as u8;
+    }
+}