skiboot-5.1.4 was released on September 26th, 2015.

skiboot-5.1.4 is the 5th stable release of 5.1, it follows skiboot-5.1.3 (which was released September 15th, 2015).

Skiboot 5.1.4 contains all fixes from skiboot-5.1.3 and is an important bug fix release and a strongly recommended update from any prior skiboot-5.1.x release.


Over skiboot-5.1.3, we have the following changes:

  • Rate limit OPAL_MSG_OCC to only one outstanding message to host

    In the event of a lot of OCC events (or many CPU cores), we could send many OCC messages to the host, which if it wasn’t calling opal_get_msg really often, would cause skiboot to malloc() additional messages until we ran out of skiboot heap and things didn’t end up being much fun.

    When running certain hardware exercisers, they seem to steal all time from Linux being able to call opal_get_msg, causing these to queue up and get “opalmsg: No available node in the free list, allocating” warnings followed by tonnes of backtraces of failing memory allocations.

  • Ensure reserved memory ranges are exposed correctly to host (fix corrupted SLW image)

    We seem to have not hit this on ASTBMC based OpenPower machines, but was certainly hit on FSP based machines