101460378SAlex Bennée.. 201460378SAlex Bennée Copyright (c) 2020, Linaro 301460378SAlex Bennée 401460378SAlex BennéeGuest Loader 501460378SAlex Bennée------------ 601460378SAlex Bennée 7*6df743dcSPeter MaydellThe guest loader is similar to the ``generic-loader`` although it is 801460378SAlex Bennéeaimed at a particular use case of loading hypervisor guests. This is 901460378SAlex Bennéeuseful for debugging hypervisors without having to jump through the 1001460378SAlex Bennéehoops of firmware and boot-loaders. 1101460378SAlex Bennée 1201460378SAlex BennéeThe guest loader does two things: 1301460378SAlex Bennée 1401460378SAlex Bennée - load blobs (kernels and initial ram disks) into memory 1501460378SAlex Bennée - sets platform FDT data so hypervisors can find and boot them 1601460378SAlex Bennée 1701460378SAlex BennéeThis is what is typically done by a boot-loader like grub using it's 1801460378SAlex Bennéemulti-boot capability. A typical example would look like: 1901460378SAlex Bennée 2001460378SAlex Bennée.. parsed-literal:: 2101460378SAlex Bennée 2201460378SAlex Bennée |qemu_system| -kernel ~/xen.git/xen/xen \ 2301460378SAlex Bennée -append "dom0_mem=1G,max:1G loglvl=all guest_loglvl=all" \ 2401460378SAlex Bennée -device guest-loader,addr=0x42000000,kernel=Image,bootargs="root=/dev/sda2 ro console=hvc0 earlyprintk=xen" \ 2501460378SAlex Bennée -device guest-loader,addr=0x47000000,initrd=rootfs.cpio 2601460378SAlex Bennée 2701460378SAlex BennéeIn the above example the Xen hypervisor is loaded by the -kernel 2801460378SAlex Bennéeparameter and passed it's boot arguments via -append. The Dom0 guest 2901460378SAlex Bennéeis loaded into the areas of memory. Each blob will get 30*6df743dcSPeter Maydell``/chosen/module@<addr>`` entry in the FDT to indicate it's location and 3101460378SAlex Bennéesize. Additional information can be passed with by using additional 3201460378SAlex Bennéearguments. 3301460378SAlex Bennée 3401460378SAlex BennéeCurrently the only supported machines which use FDT data to boot are 35*6df743dcSPeter Maydellthe ARM and RiscV ``virt`` machines. 3601460378SAlex Bennée 3701460378SAlex BennéeArguments 3801460378SAlex Bennée^^^^^^^^^ 3901460378SAlex Bennée 4001460378SAlex BennéeThe full syntax of the guest-loader is:: 4101460378SAlex Bennée 4201460378SAlex Bennée -device guest-loader,addr=<addr>[,kernel=<file>,[bootargs=<args>]][,initrd=<file>] 4301460378SAlex Bennée 4401460378SAlex Bennée``addr=<addr>`` 4501460378SAlex Bennée This is mandatory and indicates the start address of the blob. 4601460378SAlex Bennée 4701460378SAlex Bennée``kernel|initrd=<file>`` 4801460378SAlex Bennée Indicates the filename of the kernel or initrd blob. Both blobs will 4901460378SAlex Bennée have the "multiboot,module" compatibility string as well as 5001460378SAlex Bennée "multiboot,kernel" or "multiboot,ramdisk" as appropriate. 5101460378SAlex Bennée 5201460378SAlex Bennée``bootargs=<args>`` 5301460378SAlex Bennée This is an optional field for kernel blobs which will pass command 5401460378SAlex Bennée like via the `/chosen/module@<addr>/bootargs` node. 55