Is it possible to add an additional bios chip on mb using spi connector on it? I wanna start the system from it while i am experimenting, leaving the firmware in chip on mb unmodified. If it is possible, is it possible to use larger bios chip than the one which mb has?
You may disconnect CS (Chip Select) pin from board. Connect additional chip to onboard one, pin to pin,except off course CS pin. Use switch to decide which CS pin to connect to motherboard.
Is it possible to implement this without resoldering my mb, but using hold (pulling it down) and enabling both chips? Hold will disable the chip on mb so it won't prevent usage of the chip on pcb connected to spi connector. Also, can i use another flash by another vendor (atmel instead of spansion) of larger size? Now i have 1 mb chip, but 1 mb is a very little amount. But I know that bios is unable to use more than 1 mb. How will it behave if i connect 64mb flash? Will i be able then download the data out of mapped 1mb from flash?