Features/PC System Flash

From QEMU

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

Flash Hardware

Uses CFI flash support in hw/pflash_cfi01.c.

Command line interface

Usage of -bios and -pflash parameters as of pc-1.1:

KVM enabled -pflash used -bios used Result
No
Yes
-
-pflash parameter will be loaded as flash image just below 4GB.

'bios.bin' and -bios parameter will be ignored.

No
No
'bios.bin' will be used to create a read-only pflash drive.

A flash device is available, but it is read-only.

No
Yes
-bios parameter will be used to create a read-only pflash drive.

A flash device is available, but it is read-only.

Yes
Yes
-
An error message condition:

PC system firmware (pflash) not available

No
No
'bios.bin' will be loaded as rom image.

No system flash is available.

No
Yes
-bios parameter filename will be loaded as rom image.

No system flash is available.

Known Issues

  • KVM will not boot if -pflash is used and -bios is not used. KVM currently only functions with this support if code is not attempting to run from the emulated flash. This issue does not affect QEMU.