Use 'make' to assemble the BIOS:
make
Partition your SD card precisely as described in ../README-SD.md so that partition 1 starts exactly at block number 0x800 (1MiB) or the first draft of the BIOS will not work properly!
IFF you are developing on a Raspberry PI, You can install your assembled BIOS onto SD card partition 1 like this:
sudo dd if=retro.bin of=/dev/sda1 bs=512
On other systems, the drive name may be different!
Using the wrong drive name can destroy all your data!