Initial commit: XOmB exokernel foundation

Core kernel infrastructure:
- Multiboot2 boot with GRUB, long mode setup, higher-half kernel
- Serial port output for debugging
- Unified boot info abstraction for future UEFI support

Memory management:
- Physical frame allocator with bitmap tracking
- Page table manipulation via recursive mapping (PML4[510])
- Support for 4KB, 2MB, and 1GB page mappings
- TLB invalidation and proper NXE support

Build system:
- Cargo-based build with custom x86_64 target
- Makefile for QEMU and Bochs testing
- GRUB ISO generation for multiboot2 boot

.gitignore

@@ -0,0 +1,36 @@
+# Build artifacts
+/target/
+
+# IDE/Editor
+.idea/
+.vscode/
+*.swp
+*.swo
+*~
+.DS_Store
+
+# UEFI/Emulator files
+/esp/
+/esp.img
+/OVMF_VARS.fd
+
+# Bochs artifacts
+bochs.log
+debugger.log
+serial.log
+bx_enh_dbg.ini
+
+# Lock files
+esp.img.lock
+
+# Build artifacts
+/iso_staging/
+/boot_staging/
+*.iso
+
+# Backup files
+*.bak
+*.orig
+
+# Cargo lock (optional for binaries, usually committed)
+# Cargo.lock