From 728e1f057c6856963c722267ca8436bc7043100b Mon Sep 17 00:00:00 2001
From: Max Wash <mbswash@gmail.com>
Date: Sat, 21 Feb 2026 23:25:31 +0000
Subject: [PATCH] cmake: add support for gdb debugging, cd-rom boot

---
 arch/x86_64/QEMU.cmake | 109 +++++++++++++++++++++++++++++++++++------
 1 file changed, 93 insertions(+), 16 deletions(-)

diff --git a/arch/x86_64/QEMU.cmake b/arch/x86_64/QEMU.cmake
index 3f2c3eb..de36640 100644
--- a/arch/x86_64/QEMU.cmake
+++ b/arch/x86_64/QEMU.cmake
@@ -1,27 +1,34 @@
 find_program(QEMU qemu-system-${TARGET_ARCH} REQUIRED)
-find_program(LLDB lldb REQUIRED)
+if (NOT QEMU)
+	message(STATUS "QEMU: Cannot find qemu-system-${TARGET_ARCH}. Direct-kernel boot unavailable")
+	return()
+endif ()
 
+find_program(LLDB lldb)
+find_program(GDB gdb)
+
+set(patched_kernel ${CMAKE_CURRENT_BINARY_DIR}/kernel/${kernel_name}.elf32)
+
+add_custom_command(OUTPUT ${patched_kernel}
+	DEPENDS ${kernel_name}
+	COMMAND ${CMAKE_COMMAND} -E copy
+		$<TARGET_FILE:${kernel_name}>
+		${patched_kernel}
+	COMMAND ${BUILD_TOOLS_DIR}/e64patch ${patched_kernel}
+	WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+	COMMENT "Patching kernel elf64 image"
+)
+
+message(STATUS "QEMU: Enable direct-kernel boot")
 add_custom_target(run-kernel
 	COMMAND
 		${QEMU}
-		-kernel $<TARGET_FILE:${kernel_name}>
+		-kernel ${patched_kernel}
 		-initrd ${sys_dir}/${bsp_name}
-		-m 1G -serial stdio
+		-m 1G -serial stdio -enable-kvm
 		--append kernel.early-console=ttyS0
 	USES_TERMINAL
-	DEPENDS ${kernel_name} bsp)
-
-add_custom_target(debug-kernel
-	COMMAND
-		${QEMU}
-			-kernel $<TARGET_FILE:${kernel_name}>
-			-initrd ${sys_dir}/${bsp_name}
-			-m 1G -s -S &
-		${LLDB}
-			-o "file ${CMAKE_BINARY_DIR}/kernel/${kernel_name}.debug"
-			-o "gdb-remote localhost:1234"
-	USES_TERMINAL
-	DEPENDS ${kernel_name} bsp)
+	DEPENDS ${patched_kernel} bsp)
 
 add_custom_target(run-kernel-monitor
 	COMMAND
@@ -31,3 +38,73 @@ add_custom_target(run-kernel-monitor
 		-m 1G -monitor stdio
 	USES_TERMINAL
 	DEPENDS ${kernel_name} bsp)
+
+if (image_cdrom)
+	message(STATUS "QEMU: Enable CD-ROM boot")
+	add_custom_target(run-cdrom
+		COMMAND
+			${QEMU}
+			-cdrom ${image_cdrom}
+			-m 1G
+			-serial stdio
+		USES_TERMINAL
+		DEPENDS ${image_cdrom})
+endif ()
+
+if (LLDB)
+	message(STATUS "QEMU: Enable direct-kernel debug with LLDB")
+	add_custom_target(debug-kernel
+		COMMAND
+			${QEMU}
+				-kernel $<TARGET_FILE:${kernel_name}>
+				-initrd ${sys_dir}/${bsp_name}
+				-enable-kvm
+				-m 1G -s -S &
+			${LLDB}
+				-o "file ${CMAKE_BINARY_DIR}/kernel/${kernel_name}.debug"
+				-o "gdb-remote localhost:1234"
+		USES_TERMINAL
+		DEPENDS ${kernel_name} bsp)
+
+	if (image_cdrom)
+		message(STATUS "QEMU: Enable CD-ROM debug with LLDB")
+		add_custom_target(debug-cdrom
+			COMMAND
+				${QEMU}
+				-cdrom ${image_cdrom}
+				-m 1G -s -S &
+			${LLDB}
+				-o "file ${CMAKE_BINARY_DIR}/kernel/${kernel_name}.debug"
+				-o "target remote localhost:1234"
+			USES_TERMINAL
+			DEPENDS cdrom)
+	endif ()
+elseif (GDB)
+	message(STATUS "QEMU: Enable direct-kernel debug with GDB")
+	add_custom_target(debug-kernel
+		COMMAND
+			${QEMU}
+				-kernel $<TARGET_FILE:${kernel_name}>
+				-initrd ${sys_dir}/${bsp_name}
+				-m 1G -s -S &
+			${GDB}
+				-o "file ${CMAKE_BINARY_DIR}/kernel/${kernel_name}.debug"
+				-o "remote localhost:1234"
+		USES_TERMINAL
+		DEPENDS ${kernel_name} bsp)
+
+	if (image_cdrom)
+		message(STATUS "QEMU: Enable CD-ROM debug with GDB")
+		add_custom_target(debug-cdrom
+			COMMAND
+				${QEMU}
+				-cdrom ${image_cdrom}
+				-m 1G -s -S &
+			${GDB}  -tui
+				-s "${CMAKE_BINARY_DIR}/kernel/${kernel_name}.debug"
+				-ex "target remote localhost:1234"
+			USES_TERMINAL
+			DEPENDS ${image_cdrom})
+	endif ()
+endif ()
+