- rep stosl reduces ecx by 1 per write operation, not 4. Source: http://www.fermimn.gov.it/linux/quarta/x86/rep.htm
- Clarification: The four Page Directory tables contain 2048 entries in total, not 2048 each. Source: http://wiki.osdev.org/Page_Tables#Long_mode_.2864-bit.29_page_map
- Registers can not contain %rip-relative addresses, since %rip changes every single instruction. Only the instructions themselves can contain RIP-relative addresses.
- The first argument to decompress_kernel is called rmode, not boot_param.
- The boot_params struct goes in %rdi, not %rsi. Source: https://en.wikipedia.org/wiki/X86_calling_conventions#System_V_AMD64_ABI
- find_random_addr does not ensure that the 'memory region is not less than value of kernel alignment'; it ensures the kernel is at or above the minimum load address.
Alexander Kuleshov