root=/dev/ram

[Squirre17]

$ cat  ./tmp/SCTF-flying_kernel/files/boot.sh -p
#!/bin/sh
qemu-system-x86_64 \
    -m 128M \
    -kernel /home/ctf/bzImage \
    -initrd /home/ctf/rootfs.img \
    -monitor /dev/null \
    -append "root=/dev/ram console=ttyS0 oops=panic panic=1 nosmap" \
    -cpu kvm64,+smep \
    -smp cores=2,threads=2 \
    -netdev user,id=t0, -device e1000,netdev=t0,id=nic0 \
    -nographic

kernel will panic if not append root=/dev/ram

[    2.800730] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[    2.801122] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.8.18 #2
[    2.801122] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[    2.801122] Call Trace:
[    2.801122]  dump_stack+0x57/0x6b
[    2.801122]  panic+0xf3/0x2b5
[    2.801122]  mount_block_root+0x17d/0x21d
[    2.801122]  ? rdinit_setup+0x26/0x26
[    2.801122]  mount_root+0x10a/0x128
[    2.801122]  prepare_namespace+0x130/0x15f
[    2.801122]  kernel_init_freeable+0x1fb/0x20a
[    2.801122]  ? rest_init+0xb0/0xb0
[    2.801122]  kernel_init+0x5/0x110
[    2.801122]  ret_from_fork+0x22/0x30
[    2.801122] Kernel Offset: disabled