cbcmos

Synopis

cbcmos check [<dev>]
cbcmos update [<dev>]

Description

This checks or updates the CMOS-RAM checksum value against the CMOS-RAM contents. It is used with coreboot, which provides information about where to find the checksum and what part of the CMOS RAM it covers.

If <dev> is provided then the named real-time clock (RTC) device is used. Otherwise the default RTC is used.

Example

This shows checking and updating a checksum across bytes 38 and 39 of the CMOS RAM:

=> rtc read 38 2
00000038: 71 00                                            q.
=> cbc check
=> rtc write 38 66
=> rtc read 38 2
00000038: 66 00                                            f.
=> cbc check
Checksum 7100 error: calculated 6600
=> cbc update
Checksum 6600 written
=> cbc check
=>

See also cedit cb_load which shows an example that includes the configuration editor.