Question: how to transfer files to qemu?
Answer: Find the ext3 partition inside the image file: #fdisk -lu overo_sd_alip.img | grep overo. You must set cylinders. ... 
Take the “start” number of the qemu image (106496) and mount the qemu image at this offset (start multiplied by block size (512)): mkdir mnt. sudo mount -o loop,offset=$[106496*512] overo_sd_alip.img mnt.