physical memory

0x0000 - 0x1000 : GDT for kernel initialization use and some early kernel data
0x1000 - 0x2000 : kernel stage1
0x2000 - 0x3000 : kernel space PML4
0x3000 - 0x4000 : kernel PDPT for physical memory mappings
0x4000 - 0x5000 : kernel PDPT for kernel space
0x5000 - 0x6000 : kernel PD for kernel image
0x6000 - 0x7000 : kernel PT for kernel image
0x7000 - 0x8000 : kernel PD for struct page array#1

0x100000 - 0x200000 : unused
0x200000 - 0x400000 : first kernel bss page (2MB)
0x400000 - ?        : kernel image
?        - ?        : struct page array


virtual address space

0xffff ff0 000 000 000 - 0xffff ff3 fff fff fff  256GB physical memory (cached)
0xffff ff4 000 000 000 - 0xffff ff7 fff fff fff  256GB physical memory (not cached)
0xffff ff8 000 000 000 - 0xffff ff8 03f fff fff    1GB unused
0xffff ff8 040 000 000 - 0xffff ff8 13f fff fff    4GB struct page array
0xffff ff8 140 000 000 - 0xffff ff8 17f fff fff    1GB unused
0xffff ff8 180 000 000 - 0xffff ffb fff fff fff  250GB kernel heap

0xffff ffc 000 000 000 - 0xffff fff fbf fff fff  255GB unused

0xffff fff fc0 000 000 - 0xffff fff fc0 1ff fff    2MB unused
0xffff fff fc0 200 000 - 0xffff fff fff 9ff fff 1016MB kernel bss
0xffff fff fff a00 000 - 0xffff fff fff bff fff    2MB unused
0xffff fff fff c00 000 - 0xffff fff fff dff fff    2MB kernel image
0xffff fff fff e00 000 - 0xffff fff fff fff fff    2MB unused