find_kernel: initialize the allocator based on the start address for unrelocatable kernels

[cagatay-y]

I am not sure why initializing PhysAlloc after the mapping works, as the mapping functions seem to depend on it.

[mkroening]

I am not sure why initializing PhysAlloc after the mapping works, as the mapping functions seem to depend on it.

That is only true if there are no additional page tables (and thus physical frames) needed to perform the mapping. See Mapper::map_to_with_table_flags

We are also moving away from unrelocatable kernels. We now support relocatable GCC-based kernels: hermit-os/hermit-entry#37

[cagatay-y]

We are not interested in supporting any feature that is not needed by hermit, right? In that case we can remove the part for adjusting the start address based on the ELF object. Should we still add a check to see if the kernel expects to be located at a certain address and error if that's the case?

[mkroening]

Thanks a lot! This should no longer be necessary as of:

• feat(x86_64): identity-map the whole RAM and don't do any post-boot paging #576