CHAPTER 3 Devices
The SunOS 4.1.X EEPROM expects to find bootblock code in the bootblock area of a disk, sectors 1 through 15 of the first partition. This program is put there by the installboot program and allows the PROM to locate the boot program on the disk. Under SunOS 5.X the boot program and the boot block uses the drivers resident on the PROM or on the Sbus card. So the bootblock area doesn't contain the actual location of the disk block where the boot program resides. The SunOS 5.X bootblk program can read the file system to locate the boot program.