Started implementing debugging facilities

tools/kernel-debug/debug_session.py

@@ -0,0 +1,62 @@
+#!/usr/bin/env python3
+import sys
+import os
+import subprocess
+import time
+import signal
+
+
+qemu_args = []
+gdb_args  = []
+cur_program = ''
+
+
+def run_process(args):
+    p = subprocess.Popen(args,
+            bufsize=1,
+            shell=True,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE)
+
+    while True:
+        retcode = p.poll()
+        line = p.stdout.read(1)
+        yield line
+        if retcode is not None:
+            break
+
+
+for arg in sys.argv[1:]:
+    if arg == '--qemu':
+        cur_program = 'qemu'
+        continue
+    elif arg == '--gdb':
+        cur_program = 'gdb'
+        continue
+
+    if cur_program == 'qemu':
+        qemu_args += [arg]
+    elif cur_program == 'gdb':
+        gdb_args += [arg]
+    else:
+        print('No program specified')
+        exit(-1)
+
+env = os.environ.copy()
+signal.signal(signal.SIGINT, signal.SIG_IGN)
+qemu = subprocess.Popen(qemu_args,
+        env=env,
+        start_new_session=True,
+        restore_signals=False)
+time.sleep(1)
+
+if qemu.poll() is not None:
+    print('Failed to start QEMU')
+    exit(-1)
+
+subprocess.run(gdb_args,
+        env=env,
+        stdout=sys.stdout,
+        stdin=sys.stdin,
+        stderr=sys.stderr)
+qemu.kill()

tools/kernel-debug/debug_session.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+
+gdb_cfg=$1
+lldb_cfg=$2
+shift 2
+
+if command -v gdb &> /dev/null; then
+	tmux \
+		new-session -d -s hz-debug "sleep 0.3; gdb -tui -x $gdb_cfg" \; \
+		split-window -h -l 80 \; \
+		split-window -v -l 25 "$@"\; \
+		select-pane -t 0
+elif command -v lldb &> /dev/null; then
+	tmux \
+		new-session -d -s hz-debug "sleep 0.1; lldb --source $lldb_cfg" \; \
+		split-window -h -l 80 \; \
+		split-window -v -l 25 "$@"\; \
+		select-pane -t 0
+else
+	echo "No debugger available"
+	exit -1
+fi
+
+tmux a -t hz-debug
+tmux kill-session -t hz-debug
+

tools/kernel-debug/gdb_session_init

@@ -0,0 +1,4 @@
+set confirm off
+symbol-file build/socks_kernel
+target remote localhost:1234
+set confirm on

tools/kernel-debug/lldb_session_init

@@ -0,0 +1,2 @@
+file build/socks_kernel
+gdb-remote localhost:1234

tools/make/gcc-cross-compile.mk

@@ -2,7 +2,7 @@ LD  := $(ARCH)-elf-gcc
 CC  := $(ARCH)-elf-gcc
 ASM := $(ARCH)-elf-gcc
 
-CFLAGS   := -nostdlib -nostdinc -ffreestanding -Wl,-nostdlib
+CFLAGS   := -ffreestanding -nostdlib
 ASMFLAGS := $(CFLAGS)
 LDFLAGS  := -nostdlib