The BIOS allocates I/O and interrupt resources when the system boots. If your system includes many I/O devices, it might not have enough of these resources for all of them. In this case, you can reconfigure the BIOS to allocate resources to specific devices.
The resources include:
I/O space and option ROM – See Option ROM and I/O Space Allocation.
MSI interrupt assignments – See Allocating MSI Interrupt Space (Oracle Solaris OS Only).