commit 93abdf8dac67806361551a466d2cae3130824110
parent 4a304f7b63e5efcd18c0d8e0230b9d9fd91b8cc3
Author: cowmonk <cowmonk@based.pt>
Date: Mon, 21 Jul 2025 14:10:43 -0700
QEMU debugging via LLDB or optionally GDB
Diffstat:
10 files changed, 77 insertions(+), 7 deletions(-)
diff --git a/Makefile b/Makefile
@@ -1,22 +1,39 @@
all: iso
iso: kernel limine
+ @echo "Copying kernel to isodir..."
cp -v ./kernel/bin/cowos ./isodir/boot/
-
+ @echo "Creating ISO image..."
xorriso -as mkisofs -R -r -J -b boot/limine/limine-bios-cd.bin \
- -no-emul-boot -boot-load-size 4 -boot-info-table -hfsplus \
- -apm-block-size 2048 --efi-boot boot/limine/limine-uefi-cd.bin \
- -efi-boot-part --efi-boot-image --protective-msdos-label \
- isodir -o cowos.iso
-
+ -no-emul-boot -boot-load-size 4 -boot-info-table -hfsplus \
+ -apm-block-size 2048 --efi-boot boot/limine/limine-uefi-cd.bin \
+ -efi-boot-part --efi-boot-image --protective-msdos-label \
+ isodir -o cowos.iso
+ @echo "Installing Limine BIOS..."
./limine/limine bios-install cowos.iso
kernel:
- make -C ./kernel/ all
+ @echo "Buliding kernel..."
+ make -C ./kernel/
limine: kernel
+ @echo "Setting up Limine..."
./scripts/limine-git.sh
clean:
+ @echo "Cleaning up..."
rm cowos.iso
make -C ./kernel/ clean
+
+run:
+ @echo "Running cowos in QEMU..."
+ @if [ "$(DEBUG)" = "1" ]; then \
+ echo "Debug mode: Starting QEMU with LLDB..."; \
+ qemu-system-x86_64 -cdrom cowos.iso -m 512M -serial stdio -s -S & \
+ echo "Launching LLDB..."; \
+ lldb --arch x86_64 -o "gdb-remote localhost:1234" ./kernel/bin/cowos; \
+ else \
+ qemu-system-x86_64 -cdrom cowos.iso -m 512M -serial stdio; \
+ fi
+
+.PHONY: all iso kernel limine clean run
diff --git a/README.md b/README.md
@@ -15,13 +15,41 @@ You'll need a few things:
- xorriso (iso creation)
- git
- make
+
+### OPTIONAL:
- qemu (for virtual machine)
+- LLDB (debugging purposes)
After acquiring those just run make and it'll do everything for you:
```bash
make
```
+By default the kernel is compiled with debug symbols, if you would like to avoid this, you can simply override the CFLAGS:
+```bash
+cd kernel/ # it is recommended to go to the actual directory yourself
+make CFLAGS="-s -O3 -pipe"
+cd .. # return to root
+make
+```
+Eventually in the future this will be changed to be something much more convienent, however for now the inclusion of debug symbols is nessacary for development.
+
+## RUNNING
+There is now a script to automate running cowos, although it's quite simple right now, this is important for the future as cowos will eventually require a root partition and other things as it grows to userspace slowly. To run, simply run this in the root of the repository:
+```bash
+make run # This will require qemu
+```
+
+For developers, running with the DEBUG flag will launch lldb with qemu to help debug issues with cowos:
+```bash
+make DEBUG=1 run
+```
+if you do not like LLDB, I included a script called `run-gdb` in the `scripts/` directory for the gdb fans out there. I personally want to keep this project as gnu-free as possible, since I want cowos to not be GNU/cowos, I want it to just be cowos. And this means that I will even avoid anything as simple as the debugger being used to be non-GNU. Run in the root like so:
+```bash
+./scripts/run-gdb
+```
+It will automatically exit qemu if gdb is exited, and by default gdb will run in tui mode.
+
# Credits
- [Limine](https://github.com/limine-bootloader/limine): modern, advanced, portable, multiprotocol bootloader and boot manager.
diff --git a/kernel/drivers/video/framebuffer.o b/kernel/drivers/video/framebuffer.o
Binary files differ.
diff --git a/kernel/drivers/video/vga.o b/kernel/drivers/video/vga.o
Binary files differ.
diff --git a/kernel/init/kernel.o b/kernel/init/kernel.o
Binary files differ.
diff --git a/kernel/klibc/stdio.o b/kernel/klibc/stdio.o
Binary files differ.
diff --git a/kernel/klibc/string.o b/kernel/klibc/string.o
Binary files differ.
diff --git a/kernel/x86/gdt.o b/kernel/x86/gdt.o
Binary files differ.
diff --git a/scripts/limine-git.sh b/scripts/limine-git.sh
@@ -11,4 +11,8 @@ if [ ! -d ./limine/ ]; then
cp -v limine/BOOTX64.EFI isodir/EFI/BOOT/
cp -v limine/BOOTIA32.EFI isodir/EFI/BOOT/
+else
+ echo "Limine is already setup! Skipping..."
fi
+
+
diff --git a/scripts/run-gdb b/scripts/run-gdb
@@ -0,0 +1,21 @@
+#!/bin/sh
+
+echo "Starting QEMU with GDB server (localhost:1234)..."
+qemu-system-x86_64 -cdrom cowos.iso -m 512M -serial stdio -s -S &
+QEMU_PID=$!
+
+sleep 1 # just in case so we let it cook
+
+if ! ps -p $QEMU_PID > /dev/null; then
+ echo "Error: QEMU failed to start."
+ exit 1
+fi
+
+echo "Launching GDB in TUI mode..."
+gdb --tui \
+ -ex "file ./kernel/bin/cowos" \
+ -ex "target remote localhost:1234" \
+
+# kill QEMU when GDB exits
+echo "GDB exited. Terminating QEMU..."
+kill $QEMU_PID 2>/dev/null
