techblog 

I have been building a provisioning server to automate installing servers. One of the things this server will do is Jumpstart Solaris 10. The target servers are HP DL25 blades and when they tried to boot over the network I was getting an “A20 enable failed” error on the console. After many hours searching on Google I finally found this. There is a bug in boot.bin (also known as inetboot). Amazingly you need a Sun support contract to download this patch but I can now confirm that it does fix the problem.