The story as I heard it is: There original WRT54g that was the start of openWRT was BCM chip. BCM wrote a lot of the software, especially low level, as Cisco

The story as I heard it is: There original WRT54g that was the start of openWRT was BCM chip. BCM wrote a lot of the software, especially low level, as Cisco was their major customer at the time. Then Cisco got sued for GPL violations that were BCM's fault. Both companies were large and not too worried by lawsuits, but eventually it dawned on them that unlike the usual between businesses, they weren't just going to be able to settle by paying some money, because their antagonists were not in it for the money. They had to release the source, which both companies regarded as significantly part of their own IP. Cisco was pissed at BCM, BCM were upset that an external factor could piss off their major customer like this, and some high ranked individuals at BCM were butthurt about open source licenses having a say in their operations. So a policy was put in place that where significant R&D effort was made on software, in product lines those individuals controlled, it would be legally firewalled from open source licenses, even to the extent of designing future chip architectures so that there were extra processors, not running Linux, that would run features BCM wanted to keep proprietary. So that's why it's difficult to run open WRT on BCM chips. Caveat: I did not get this first or second hand.