From Lazarus wiki
A dedicated kernel for multi-threading applications
- you'll need to have cross-compile linux binary utils
- those could be acquired from fpcup or fpcupdeluxe
- the project contain "build" utility complication as well. The utiltiy produces an image from the resulting .elf file
- install QEmu for Windows
- run the system specifying the built image
qemu-system-x86_64 -hda HelloWorldMicroservice.img
- on start qemu can complain about unknown or raw format of ".img" file.
- One might find the script files to build the Qemu recognizable image file formats: BuildVHDX.cmd and/or BuildVMDK.cmd
- run QEmu with enabling gdb (-s) and also requesting the QEmu to halt until getting the "continue" signal from gdb (-S)
qemu-system-x86_64 -s -S -hda HelloWorldMicroservice.img
- The expected result is that Qemu window will halt with the message that "vga" system has not been initialized yet (and doing nothing)
- -s - configures the default remote GDB mode for the use of TCP socket for port 1234
- run the debugger, and provide the previously complied binary file as its gdb target. (The file is needed to load debugging information)
- after that run the remote target command
(gdb)> target remote localhost:1234
- The command makes gdb connect to the specified address. In which case this would be Qemu running locally at port 1234.
- setup the debugging information (i.e. breakpoints, etc)
- The debugging information in the compiled binary contains the information necessary to work with binary during debugging.
- "continue" the process.