qemu shows blank screen in NOVA while running make run/virtualbox.
i have added QEMU_OPT += -display sdl to build.conf and changed environment variable also export SDL_VIDEO_X11_DGAMOUSE=0 and i have demo scenario as test.iso the terminal shows something like this:

[init -> acpi_drv] MADT IRQ 0 -> GSI 2 flags: 0
[init -> acpi_drv] MADT IRQ 5 -> GSI 5 flags: d
[init -> acpi_drv] MADT IRQ 9 -> GSI 9 flags: d
[init -> acpi_drv] MADT IRQ 10 -> GSI 10 flags: d
[init -> acpi_drv] MADT IRQ 11 -> GSI 11 flags: d
[init -> fb_drv] int Framebuffer_drv::map_io_mem(Genode::addr_t, Genode::size_t, bool, void**, Genode::addr_t, Genode::Dataspace_capability*): fb mapped to 1000
[init -> ps2_drv] Could not open ROM session for module "config"
[init -> ps2_drv] Could not obtain config file
[init -> ps2_drv] Using keyboard with scan code set 1 (xlate).
[init -> ps2_drv] Detected ExPS/2 mouse - activating scroll-wheel and 5-button support.
[init -> platform_drv] PS2 uses IRQ, vector 0x1
[init -> platform_drv] PS2 uses IRQ, vector 0xc
[init -> virtualbox] using the pipe libc plugin
[init -> virtualbox] getenv called for non-existent variable "XML_MEM_BREAKPOINT"
[init -> virtualbox] getenv called for non-existent variable "XML_MEM_TRACE"
[init -> virtualbox] getenv called for non-existent variable "LC_ALL"
[init -> virtualbox] getenv called for non-existent variable "LC_CTYPE"
[init -> virtualbox] getenv called for non-existent variable "LANG"
[init -> virtualbox] getenv called for non-existent variable "PATH_LOCALE"
[init -> virtualbox] getenv called for non-existent variable "VBOX_DISABLE_HOST_DISK_CACHE"
[init -> virtualbox] getenv called for non-existent variable "CHARSETALIASDIR"
[init -> virtualbox] getenv called for non-existent variable "TZ"
[init -> virtualbox] getenv called for non-existent variable "TZ"
[init -> virtualbox] fcntl(): command 2 not supported
[init -> virtualbox] Log created: 2016-06-26T13:02:00.971000000Z
[init -> virtualbox] main     Executable: /virtualbox
[init -> virtualbox] SystemProperties : Cannot determine default Guest Additions ISO location. Most likely they are not available
[init -> virtualbox] main     genodeConsole = 0000000000b87880
[init -> fb_drv] Could not open ROM session for module "config"
[init -> fb_drv] Could not obtain config file
[init -> fb_drv] Found: VESA BIOS version 3.0
[init -> fb_drv] OEM: SeaBIOS VBE(C) 2011
[init -> fb_drv] Found: physical frame buffer at 0xfc000000 size: 0x00400000
[init -> fb_drv] int Framebuffer_drv::map_io_mem(Genode::addr_t, Genode::size_t, bool, void**, Genode::addr_t, Genode::Dataspace_capability*): fb mapped to 400000
[init -> fb_drv] Using video mode: 1280 x 1024 x 16
[init -> virtualbox] getenv called for non-existent variable "VBOX_USER_VMLOGDIR"
[init -> virtualbox] requested stack for thread 'EMT' of 1048576 Bytes is too large, limit to 1036288 Bytes
[init -> virtualbox] getenv called for non-existent variable "VBOX_SUPLIB_FAKE"
[init -> virtualbox] EMT      Initial balloon size 0
[init -> virtualbox] Could not open ROM session for module "usb_devices"
[init -> virtualbox] Warning: abort called - thread: vCPU dispatcher
[init] virtual void Genode::Child_policy::exit(int): child "virtualbox" exited with exit value 1
int main(): --- init created, waiting for exit condition ---