Unobfuscate "KERNLOAD" parameter on amd64

[sobomax]

Summary

Kernel loading address seems like important parameter that somehow got scrambled up while developing amd64.

This change lines-up amd64 with the i386 and the rest of supported architectures by defining KERNLOAD in the vmparam.h and getting rid of magic constant in the linker script.

Use KERNLOAD to eliminate another (matching) magic constant 200 lines down inside unassuming TU "copy.c" 3 levels deep in the loader tree.

[markj]

stand/efi/loader/copy.c

36

Why is the seatbelt needed?

[sobomax]

stand/efi/loader/copy.c

36

Good question. I was not sure if I am going to break other arches or people building on older systems perhaps? But if that's OK, I'd be glad to get rid of this if you guys think it's not needed.

[markj]

stand/efi/loader/copy.c

36

I see now that KERNEL_PHYSICAL_BASE is only used if __i386__ or __amd64__ is defined, so the definition should move into that block and the warning can be dropped, IMO.

[sobomax]

Eliminate KERNEL_PHYSICAL_BASE althogether, move #include <machine/vmparam.h> into i386/amd64-specific section.

Suggested by: markj

[sobomax]

Updated, thanks @markj !

[markj]

sys/amd64/include/vmparam.h

155

I would s/size/alignment/ in the comment. I believe the kernel expects to be loaded on a superpage boundary, it doesn't have to be 0x200000 specifically.

[sobomax]

Merge in comments for the KERNLOAD into one blob.