qfw command
Synopsis
qfw list
qfw cpus
qfw load [kernel_addr [initrd_addr]]
Description
The qfw command is used to retrieve information from the QEMU firmware.
The qfw list sub-command displays the QEMU firmware files.
The qfw cpus sub-command displays the available CPUs.
The qfw load command is used to load a kernel and an initial RAM disk.
- kernel_addr
address to which the file specified by the -kernel parameter of QEMU shall be loaded. Defaults to environment variable loadaddr and further to the value of CONFIG_SYS_LOAD_ADDR.
- initrd_addr
address to which the file specified by the -initrd parameter of QEMU shall be loaded. Defaults to environment variable ramdiskaddr and further to the value of CFG_RAMDISK_ADDR.
Examples
QEMU firmware files are listed via the qfw list command:
=> qfw list
Addr Size Sel Name
---------------- -------- --- ------------
0 0 20 bios-geometry
0 0 21 bootorder
1fc6c000 14 22 etc/acpi/rsdp
1fc6c040 20000 23 etc/acpi/tables
0 4 24 etc/boot-fail-wait
0 28 25 etc/e820
0 8 26 etc/msr_feature_control
0 18 27 etc/smbios/smbios-anchor
0 151 28 etc/smbios/smbios-tables
0 6 29 etc/system-states
0 1000 2a etc/table-loader
0 0 2b etc/tpm/log
0 2400 2c genroms/kvmvapic.bin
Where an address is shown, it indicates where the data is available for inspection, e.g. using the md command.
The available CPUs can be shown via the qfw cpus command:
=> qfw cpu
2 cpu(s) online
The -kernel and -initrd parameters allow to specify a kernel and an initial RAM disk for QEMU:
$ qemu-system-x86_64 -machine pc-i440fx-2.5 -bios u-boot.rom -m 1G \
-nographic -kernel vmlinuz -initrd initrd
Now the kernel and the initial RAM disk can be loaded to the U-Boot memory via the qfw load command and booted thereafter.
=> qfw load ${kernel_addr_r} ${ramdisk_addr_r}
loading kernel to address 0000000001000000 size 5048f0 initrd 0000000004000000 size 3c94891
=> zboot 1000000 5048f0 4000000 3c94891
Valid Boot Flag
Magic signature found
Linux kernel version 4.19.0-14-amd64 (debian-kernel@lists.debian.org) #1 SMP Debian 4.19.171-2 (2021-01-30)
Building boot_params at 0x00090000
Loading bzImage at address 100000 (5260160 bytes)
Configuration
The qfw command is only available if CONFIG_CMD_QFW=y.