The structure boot_params contains the boot header from the linux boot protocol. This structure gets filled by copying the original boot header, at offset 0x1f1 of bzImage, into the .bss section of setup.elf, this happens in copy_boot_params(). This .bss section is still under 1MB of RAM. The physical address of this structure is then saved in r15. My question is about accessing this structure after paging is enabled: