tests: add some exec tests

Signed-off-by: Amneesh Singh <natto@weirdnatto.in>

include/bus.hh

@@ -5,7 +5,7 @@
 
 class Bus {
   public:
-    Bus(Memory& memory);
+    Bus(const Memory& memory);
 
     uint8_t read_byte(size_t address);
     void write_byte(size_t address, uint8_t byte);

include/cpu/arm/instruction.hh

@@ -156,6 +156,10 @@ struct Instruction {
     InstructionData data;
 
     Instruction(uint32_t insn);
+    Instruction(Condition condition, InstructionData data) noexcept
+      : condition(condition)
+      , data(data){};
+
     std::string disassemble();
 };
 }

include/cpu/arm/meson.build

@@ -0,0 +1,3 @@
+headers += files(
+  'instruction.hh',
+)

include/cpu/cpu.hh

@@ -1,7 +1,7 @@
 #pragma once
 
+#include "arm/instruction.hh"
 #include "bus.hh"
-#include "instruction.hh"
 #include "psr.hh"
 
 #include <cstdint>
@@ -10,7 +10,7 @@ using std::size_t;
 
 class Cpu {
   public:
-    Cpu(Bus& bus);
+    Cpu(const Bus& bus);
     void step();
 
   private:
@@ -30,7 +30,9 @@ class Cpu {
     Psr spsr; // status program status register
 
     static constexpr uint8_t PC_INDEX = 15;
-    uint32_t& pc                      = gpr[PC_INDEX];
+    static_assert(PC_INDEX < GPR_COUNT);
+
+    uint32_t& pc = gpr[PC_INDEX];
 
     bool is_flushed;
 

include/cpu/meson.build

@@ -1,6 +1,7 @@
 headers += files(
   'cpu.hh',
-  'instruction.hh',
   'psr.hh',
   'utility.hh'
-)
+)
+
+subdir('arm')

include/memory.hh

@@ -10,8 +10,7 @@ class Memory {
   public:
     static constexpr size_t BIOS_SIZE = 1024 * 16;
 
-    Memory(std::array<uint8_t, BIOS_SIZE>&& bios,
-           std::vector<uint8_t>&& rom) noexcept;
+    Memory(std::array<uint8_t, BIOS_SIZE>&& bios, std::vector<uint8_t>&& rom);
 
     uint8_t read(size_t address) const;
     void write(size_t address, uint8_t byte);