FYI you don't need to run the second stage of debootstrap/dpkg on the device. You can install qemu-user-static, "cp /usr/bin/qemu-arm-static path/to/sd/card/mount/usr/bin/" and then you can chroot there from your x86 machine. It works by registering a handler in /proc/sys/fs/binfmt_misc and then it runs the binaries with qemu.