66 Intel® Server System SR1520ML User’s Guide
Using the iBMC Boot Block Write Protect Jumper (J1A4)The iBMC boot block write protect jumper (J1A4) is protection for the boot block portion
of the iBMC firmware. The default position of the jumper is covering pins 1-2. This
protects the boot block from being written to during an iBMC firmware update. In most
cases there is no need to update the boot block. Most update utilities are not built with the
authority to access this section of code.
In the unlikely event that the boot block must be written to, the J1A4 jumper must be
moved to cover pins 2-3 to enable the update. Once the update is complete and the system
is turned off, always remember to reposition the jumper back to ‘write-protect’ mode,
covering pins pins 1-2.
Note: The boot block is a critical section of the IBMC firmware that contains code to initialize
the iBMC hardware. If this flash area becomes corrupted, then the iBMC may be rendered
useless and inoperable. For this reason jumper protection is applied to this area of the
flash so a user does not mistakenly write to this boot block.