Arcboot uses ARC PROM variables to find out what it's supposed to load and from where. The PROM variable OSLoadPartition must point to the partition that has the kernel and the configuration file arcboot.conf. PROM variable OSLoadFilename should contain a label pointing to a label section in the configuration file. If the label can't be found then arcboot tries to load a file in OSLoadFilename. Kernel parameters can be given in arcboot.conf using the append="..." directive and also using PROM variable OSLoadOptions.
You can also give extra command line options at the PROM prompt:
arcboot linux console=ttyS0 root=/dev/sda1
The OSLoadPartition partition name must be in the format used by ARCS, for example scsi(0)disk(1)rdisk(0)partition(0)
label=linux image=/vmlinux append="root=/dev/sda1 ro video=1024x768-16@60"