626c9705d2
On my machine, it happens once in a while that the virtualised machine boots too fast for the rootfs to be available at the time the kernel tries to mount it. For example, board/qemu/arm-vexpress/readme.txt suggested changing "-smp 1" up to "-smp 4". But doing so here causes a kernel panic: VFS: Cannot open root device "mmcblk0" or unknown-block(0,0): error -6 Please append a correct "root=" boot option; here are the available partitions: 1f00 131072 mtdblock0 (driver?) 1f01 32768 mtdblock1 (driver?) Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) So, add the oh-so-useful 'rootwait' option to all kernel command lines for qemu defconfigs. Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr> Cc: Joel Stanley <joel@jms.id.au> Cc: Mark Corbin <mark.corbin@embecosm.com> Cc: Matt Weber <matthew.weber@rockwellcollins.com> Signed-off-by: Peter Korsgaard <peter@korsgaard.com> |
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readme.txt |
Run the emulation with: qemu-system-arm -M vexpress-a9 -smp 1 -m 256 -kernel output/images/zImage -dtb output/images/vexpress-v2p-ca9.dtb -drive file=output/images/rootfs.ext2,if=sd,format=raw -append "console=ttyAMA0,115200 rootwait root=/dev/mmcblk0" -serial stdio -net nic,model=lan9118 -net user The login prompt will appear in the terminal that started Qemu. The graphical window is the framebuffer. If you want to emulate more cores change "-smp 1" to "-smp 2" for dual-core or even "smp -4" for a quad-core configuration. Tested with QEMU 2.12.0