Making the default MAC address and machine serial number depend entirely on the NVRAM/RTC battery is... a choice. You'd think they would have used some fusible links to burn the original values into the hardware to fall back on if the battery died.
Making the default MAC address and machine serial number depend entirely on the NVRAM/RTC battery is... a choice. You'd think they would have used some fusible links to burn the original values into the hardware to fall back on if the battery died.
Nobody burns in MAC addresses. MAC is usually stored on eeprom. Either in BIOS or small i2c one on the NIC. Storing it in the nvram means you save $0.1 BOM, dont have to partition your bios chip and serialization becomes cheaper and faster. Its not like losing one is a problem, just bang a random number with Sun prefix and you will be statistically fine.