Running JNode in QEMU¶

Basic Boot¶

# Minimal, serial-only (fastest for testing)
qemu-system-x86_64 -cdrom all/build/cdroms/jnode-x86-lite.iso \
  -m 512 -serial stdio -display none

With Serial Log File¶

# Capture boot log to file + see it live
rm -f /tmp/jnode-serial.log
qemu-system-x86_64 -cdrom all/build/cdroms/jnode-x86-lite.iso \
  -m 1024 -M pc -cpu pentium -boot once=d \
  -serial file:/tmp/jnode-serial.log -display none &
tail -f /tmp/jnode-serial.log

With Networking (User-mode / SLIRP)¶

# User-mode networking (no root needed)
qemu-system-x86_64 -cdrom all/build/cdroms/jnode-x86-lite.iso \
  -m 1024 -netdev user,id=net0 -device rtl8139,netdev=net0 \
  -serial stdio -display none

Inside JNode:

jnode> dhcp eth0
jnode> ping 10.0.2.2   # Host gateway

With Bridged Networking (Requires Root)¶

# Replace br0 with your bridge interface
sudo qemu-system-x86_64 -cdrom all/build/cdroms/jnode-x86-lite.iso \
  -m 1024 -netdev bridge,id=net0,br=br0 -device rtl8139,netdev=net0 \
  -serial stdio -display none

With KVM Acceleration (Linux Host)¶

qemu-system-x86_64 -cdrom all/build/cdroms/jnode-x86-lite.iso \
  -m 1024 -enable-kvm -cpu host \
  -serial stdio -display none

x86_64 Build¶

qemu-system-x86_64 -cdrom all/build/cdroms/jnode-x86_64-lite.iso \
  -m 1024 -cpu qemu64 -serial stdio -display none

Debugging with GDB¶

# Terminal 1: Start QEMU paused at boot
qemu-system-x86_64 -cdrom all/build/cdroms/jnode-x86-lite.iso \
  -m 512 -s -S -serial stdio -display none

# Terminal 2: Connect GDB to kernel entry
gdb -ex "target remote localhost:1234" \
    -ex "set architecture i386" \
    -ex "break _start" \
    -ex "continue"

Useful QEMU Options¶

Option	Purpose
`-serial stdio`	Serial console on terminal
`-serial file:log.txt`	Serial to file
`-serial telnet::4444,server,nowait`	Telnet to port 4444
`-display none`	Headless (no GUI window)
`-m 1024`	1 GB RAM
`-cpu pentium`	32-bit Pentium class (required for 32-bit ISO)
`-cpu qemu64`	64-bit CPU
`-enable-kvm`	KVM acceleration
`-s -S`	GDB server on :1234, pause at start

CI Configuration¶

The CI uses .github/qemu/jnode.properties and boots with:

qemu-system-x86_64 -cdrom ./all/build/cdroms/jnode-x86-lite.iso \
  -m 1024 -M pc -cpu pentium -boot once=d,menu=off -net none \
  -serial file:/tmp/com1.txt -display none

See QEMU Wiki for boot process details.