On 05/05/17 09:57, Fu Wei wrote: > Hi Stefano, > > On 4 May 2017 at 04:53, Stefano Stabellini <sstabell...@kernel.org> wrote: >> On Wed, 3 May 2017, Andrew Cooper wrote: >>> On 02/05/17 08:06, fu....@linaro.org wrote: >>>> From: Fu Wei <fu....@linaro.org> >>>> >>>> This patch adds the support of xen_boot command for aarch64: >>>> xen_hypervisor >>>> xen_module >>>> These two commands are only for aarch64, since it has its own protocol and >>>> commands to boot xen hypervisor and Dom0, but not multiboot. >>>> >>>> For other architectures, they are still using multiboot and module >>>> commands. >>>> >>>> Signed-off-by: Fu Wei <fu....@linaro.org> >>> Sorry if I am jumping in late and asking awkward questions, but what is >>> special about Xen/aarch64 here? Why is it using a non-standard entry >>> mechanism? >> Multiboot is not available on ARM. The boot protocol we have on ARM is >> FDT based: >> >> http://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/misc/arm/device-tree/booting.txt >> >> We often refer to it as "multiboot for arm" but in fact it is not >> related to the x86 multiboot in any way. >> >> In Grub, the two protocols (multiboot and >> docs/misc/arm/device-tree/booting.txt) are kept clearly distinct >> (55a687e5.4070...@gmail.com). Hence, the need for this patch. > Exactly, great thanks for your explanation! :-)
So it really is an entirely custom Xen booting protocol. It is unfortunate that this wasn't reviewed sensibly at the time (and implemented in a project-neutral way), but it looks like the time to fix that properly has long since passed. ~Andrew _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org https://lists.gnu.org/mailman/listinfo/grub-devel