loading two fpga devices from the same flash

Loading two FPGA's with the same configuration is relatively simple and documented in the device handbook.

I am not aware of any automated way if the contents are different:

Here's a possible solutions however:

First FPGA loads in Active serial mode, then a small Micro or NIOS processor built into that FPGA reads and programs the second FPGA in a Passive serial fashion.

This method to read the EPCS would be the same the NIOS II core uses to have FPGA and Source code in the same EPCS flash device. If you are using NIOS, Altera provides the core to access this the primary EPCS for it's code space:

http://www.altera.com/support/kdb/solutions/rd03032006_690.html

To program the secondary FPGA, could be just bit banged, from the first.

If you have an external CPU with flash present in the system, It's probably easiest to just have it program both FPGA's in passive serial mode (Modified SPI). Of course this only works if the CPU doesn't require the FPGA to boot.

Pete