maybe misunderstanding doc

[Davidrjx]

as for linux/Documentation/kdump/kdump.txt, 1MB as starting address in statement "This will compile the kernel for physical address 1MB" is right? by context, no any related content is found.

4) Use a suitable value for "Physical address where the kernel is
   loaded" (under "Processor type and features"). This only appears when
   "kernel crash dumps" is enabled. A suitable value depends upon
   whether kernel is relocatable or not.

   If you are using a relocatable kernel use CONFIG_PHYSICAL_START=0x100000
   This will compile the kernel for physical address 1MB, but given the fact
   kernel is relocatable, it can be run from any physical address hence
   kexec boot loader will load it in memory region reserved for dump-capture
   kernel.