QFW Bootmeth

QEMU is a system emulator which is able to boot Operating Systems. QEMU provides specific support for booting an OS image provided on the QEMU command line.

When invoked on a bootdev for UCLASS_QFW, this bootmeth reads the kernel provided by the QEMU -kernel argument, the initial ramdisk provided by -initrd and the boot arguments (command line) provided by -append into memory ready for booting.

When the bootflow is booted, the bootmeth tries the booti option first, then falls back to the bootz option, then zboot. U-Boot’s ‘control’ devicetree is passed through to the kernel on non-x86 devices. This works without needing CONFIG_CMDLINE enabled.

The bootflow read command is supported, so it is possible to read the files and then check the kernel command-line before using bootflow boot to boot.

The compatible string “u-boot,qfw-bootmeth” is used for the driver. It is present if CONFIG_QFW is enabled.