How to reduce bios6 build time in IPNC GA3.0 ?

Hi,

As subject, I wonder it takes several minutes to build bios6 target.

In my case, 'make -s mcfw_bios6' takes about 9 minute, but 'make -s mcfw_linux' takes only a few seconds in my intel i5-3 3570K (ivy bridge) core.

If abnormal, is there any way to reduce this time?

Thanks.