Initial commit: raisernics toy kernel

- Bare-metal x86_64 UEFI kernel (PE32+, no libc)
- GOP framebuffer + 8x16 bitmap font
- PS/2 keyboard (polling, scancode set 1)
- UART 16550 serial driver (COM1, 115200 8N1)
- Bump allocator as #[global_allocator] (alloc::String, Vec, format!)
- UEFI memory map capture (static buffer, ADR 0001)
- Shell with 7 commands (help, echo, clear, hello, info, mem, halt)
- Dual output: GOP framebuffer + serial console
- Makefile: run, run-gui, debug, release, image targets
- tools/: qemu.sh, boot-image.sh, debug-kernel.py

1 files changed, 64 insertions, 0 deletions

diff --git a/tools/debug-kernel.py b/tools/debug-kernel.py
new file mode 100755
index 0000000..c794ad6
--- /dev/null
+++ b/tools/debug-kernel.py
@@ -0,0 +1,64 @@
+"""
+GDB Python script for debugging raisernics under QEMU.
+
+Usage:
+  1. Terminal 1: ./tools/qemu.sh --debug
+  2. Terminal 2: gdb -x tools/debug-kernel.py target/x86_64-unknown-uefi/debug/raisernics.efi
+"""
+
+import gdb
+import os
+
+# Find the kernel binary
+script_dir = os.path.dirname(os.path.abspath(__file__))
+project_root = os.path.dirname(script_dir)
+binary = os.path.join(
+    project_root,
+    "target/x86_64-unknown-uefi/debug/raisernics.efi"
+)
+
+# Connect to QEMU's GDB stub
+gdb.execute("target remote :1234")
+
+# Load the binary (add symbol table)
+if os.path.exists(binary):
+    gdb.execute(f"symbol-file {binary}")
+    print(f"Loaded symbols from {binary}")
+else:
+    print(f"WARNING: {binary} not found. Build with debug symbols first.")
+
+gdb.execute("set breakpoint pending on")
+
+
+# Helper commands
+class DumpBootServices(gdb.Command):
+    """Dump EFI boot services signature and key pointers"""
+
+    def __init__(self):
+        super().__init__("dump-bs", gdb.COMMAND_USER)
+
+    def invoke(self, argument, from_tty):
+        del argument, from_tty
+        gdb.execute("printf \"SystemTable, BootServices, and key function pointers\\n\"")
+        gdb.execute("info functions efi_main")
+
+
+class DumpGop(gdb.Command):
+    """Dump GOP framebuffer info"""
+
+    def __init__(self):
+        super().__init__("dump-gop", gdb.COMMAND_USER)
+
+    def invoke(self, argument, from_tty):
+        del argument, from_tty
+        gdb.execute("printf \"Check the gop::Framebuffer static\\n\"")
+
+
+DumpBootServices()
+DumpGop()
+
+print("")
+print("raisernics GDB session ready.")
+print("  target remote :1234 (connected)")
+print("  Commands: continue, stepi, bt, info registers, etc.")
+print("  Custom:   dump-bs, dump-gop")