initialise a memory structure or smth

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

apps/target/main.cc

@@ -1,15 +1,74 @@
-#include "emulator.hh"
+#include "memory.hh"
+#include <array>
+#include <cstdlib>
+#include <fstream>
 #include <iostream>
+#include <vector>
 
 int
 main(int argc, const char* argv[]) {
-    if (argc != 2) {
-        std::cerr << "Usage: " << argv[0] << " <file>" << std::endl;
-        return 1;
+    auto usage = [argv]() {
+        std::cerr << "Usage: " << argv[0] << " <file> [-b <bios>]" << std::endl;
+        std::exit(EXIT_FAILURE);
+    };
+
+    if (argc < 2)
+        usage();
+
+    std::string rom_file, bios_file = "gba_bios.bin";
+
+    for (int i = 1; i < argc; ++i) {
+        std::string arg = argv[i];
+
+        if (arg == "-b") {
+            if (++i < argc)
+                bios_file = argv[i];
+            else
+                usage();
+        } else {
+            rom_file = arg;
+        }
     }
 
+    if (rom_file.empty())
+        usage();
+
     try {
-        emulator::run(argv[1]);
+        std::ifstream ifile(rom_file, std::ios::in | std::ios::binary);
+        std::vector<uint8_t> rom;
+        std::array<uint8_t, Memory::BIOS_SIZE> bios;
+        std::streampos bios_size;
+
+        if (!ifile.is_open()) {
+            throw std::ios::failure("File not found", std::error_code());
+        }
+
+        rom.assign(std::istreambuf_iterator<char>(ifile),
+                   std::istreambuf_iterator<char>());
+
+        ifile.close();
+
+        ifile.open(bios_file, std::ios::in | std::ios::binary);
+
+        if (!ifile.is_open()) {
+            throw std::ios::failure("BIOS file not found", std::error_code());
+        }
+
+        ifile.seekg(0, std::ios::end);
+        bios_size = ifile.tellg();
+
+        if (bios_size != Memory::BIOS_SIZE) {
+            throw std::ios::failure("BIOS file has invalid size",
+                                    std::error_code());
+        }
+
+        ifile.seekg(0, std::ios::beg);
+
+        ifile.read(reinterpret_cast<char*>(bios.data()), bios.size());
+
+        ifile.close();
+
+        Memory memory(std::move(bios), std::move(rom));
     } catch (const std::exception& e) {
         std::cerr << "Exception: " << e.what() << std::endl;
         return 1;