I have a raw qemu disk image of Debian 10 ("buster") with no desktop environment, and I'm trying to run it in the terminal of my host machine (also Debian 10) with the -curses flag. If I run qemu-system-x86_64 with just the -curses flag, I just get a blank screen, so following this question I added the -vga std option. Unfortunately, that gives me a kernel panic in the console, and I never reach the login screen of the guest. The output looks like this:
[ 3.021788] xwrite+0x29/0x5a
[ 3.021845] do_copy+0x9b/0xc8
[ 3.021878] write_buffer+0x27/0x37
[ 3.021912] flush_buffer+0x34/0x8b
[ 3.021947] __gunzip+0x26e/0x315
[ 3.021982] ? bunzip2+0x397/0x397
[ 3.022016] ? initrd_load+0x5e/0x5e
[ 3.022048] ? __gunzip+0x315/0x315
[ 3.022080] gunzip+0xe/0x11
[ 3.022112] ? initrd_load+0x5e/0x5e
[ 3.022143] unpack_to_rootfs+0x182/0x2c6
[ 3.022177] ? initrd_load+0x5e/0x5e
[ 3.022210] ? unpack_to_rootfs+0x2c6/0x2c6
[ 3.022243] ? do_early_param+0x8e/0x8e
[ 3.022275] populate_rootfs+0x59/0x106
[ 3.022311] do_one_initcall+0x46/0x1c3
[ 3.022350] ? do_early_param+0x8e/0x8e
[ 3.022382] kernel_init_freeable+0x189/0x218
[ 3.022419] ? rest_init+0xaa/0xaa
[ 3.022453] kernel_init+0xa/0x10d
[ 3.022487] ret_from_fork+0x35/0x40
[ 3.023243] ---[ end Kernel panic - not syncing: System is deadlocked on memo
ry
[ 3.023243] ]---
I'm using QEMU emulator version 3.1.0 (Debian 1:3.1+dfsg-8+deb10u3). My terminal is st 0.8.2 and my desktop environment/window manager is dwm, if those details are relevant. I get the same kernel panic if I use xterm, though.
I'm booting the image with this qemu command:
qemu-system-x86_64 -curses -vga std -m 1024 -drive format=raw,file=disk.img
I've tried other various combinations of qemu flags from this question, but they either don't exist for my version of qemu (e.g. the -noframe option), throw other errors (e.g. -append requires a -kernel option), or just give me a blank screen (-curses by itself).
The whole point of this is to avoid launching a VNC viewer to access a guest that is command line only anyway.
qemu -curses, just give it thenomodeset(andsystemd.unit=multi-user.target) options on the kernel command line (I don't think that using-append ...works if you're using any kind of boot manager in the guest). Otherwise sooner or later you'll be left with with a black screen withgraphics modewritten in the middle. I'm sorry I can't help you further, as I'm using a (heavily modified) current version of qemu, not that from the distro. I'm also using-vga virtio, but I don't know if that works with your older version. – mosvy Dec 10 '19 at 20:13qemu-system-x86_64command? I can't even get into a boot menu in qemu so I can't (for example) edit boot commands in grub. – Michael A Dec 10 '19 at 20:30grubcan pass arguments to the linux kernel.qemuknows how to do that directly, if you're using-kernel ... -append .., but that doesn't work with disk images which use a bootloader. Eg. if your image is usinggrub, you can modify them by pressingein the boot screen, adding them after thelinuxentry, and then pressing Ctrl-X to boot through. You can add permanent kernel command options inside the guest by modifying/etc/default/gruband runninggrub-update. All that is no different from a real machine. – mosvy Dec 10 '19 at 20:35nomodeset systemd.unit=multi-user.targetto theGRUB_CMDLINE_LINUX_DEFAULT="quiet nomodeset systemd.unit=multi-user.target"line in/etc/default/grub, ranupdate-grub, and now theqemu-system-x86_64command in my question works perfectly! Plus I can get easily get that to work with my preseed file. I'm happy to summarize this and put it into a community wiki answer, unless you want to. Thank you again! – Michael A Dec 10 '19 at 20:44