This is a proposal for PC System Flash emulation for on QEMU/KVM.

Flash Hardware

Leverage the pre-existing CFI flash support in qemu/hw/pflash_cfi01.c. (Another option is to use qemu/hw/pflash_cfi02.c.)

Command line interface

Today the (currently existing) -pflash parameter has no use with an x86 or x86-64 system. To enable PC system flash, this parameter would now be used on x86 & x86-64 systems. The -bios parameter would take priority over -pflash, but one or both could be used with qemu/kvm as follows:

-bios used	-pflash used	Result
No	No	(no change) 'bios.bin' will be loaded as rom image.
Yes	No	(no change) -bios parameter will be loaded as rom image.
No	Yes	(changing) -pflash parameter will be loaded as flash image just below 4GB. 'bios.bin' will be ignored.
Yes	Yes	(changing) -bios parameter will be loaded as rom image just below 4GB. -pflash parameter will be loaded as flash image just below the bios rom image.