Короче, вот комманда запуска:
switch=lan1 qemu-system-i386 -hda ./gs.img -net nic,model=e1000 -net tap,ifname=if10 -mtdblock ./mtd.img -serial stdio
Вот вывод /proc/mtd:
/ # cat /proc/mtd
dev: size erasesize name
mtd0: 00400000 00020000 "mtdram test device"
mtd1: 08000000 00004000 "NAND 128MiB 1,8V 8-bit"
mtd2: 08000000 00004000 "NAND simulator partition 0"
/ #