MemPhysMarkAddrRange: ;;;void MemPhysMarkAddrRange(eax:baseaddr, ecx:length)
    ;ebx will be my bitmap base
    ;edx will be my subword len
    ;esi is my whatever register
    ;edi is if it's necessary to align the length
    ;eax is the index

    push ebp
    mov ebp, esp
    sub esp, 8

    push ebx
    push edx
    push esi
    push edi

    xor edi, edi
    test ecx, 0xFFF
    jz .no_partial_block
        inc edi
    .no_partial_block:
    shr ecx, 12
    shr eax, 12

    mov ebx, eax
    and ebx, 31
    mov edx, 32
    sub edx, ebx

    cmp ecx, edx
    jge .len_big_enough
        mov edx, ecx
    .len_big_enough:
    sub ecx, edx

    mov esi, 1
    add edx, edi
    shl esi, dl
    dec esi
    shl esi, bl
    shr eax, 5
    or dword [physmem_bitmap + eax * 4], esi

    inc eax
    mov esi, ecx
    shr esi, 5
    add esi, eax

    .fill_loop_top:
        cmp eax, esi
        je .fill_loop_done

        mov dword [physmem_bitmap + eax * 4], 0xFFFFFFFF
        inc eax

        jmp .fill_loop_top
    .fill_loop_done:

    and ecx, 31
    jz .no_remaining_bits
        mov esi, 1
        shl esi, cl
        dec esi
        or dword [physmem_bitmap + eax * 4], esi
    .no_remaining_bits:

    pop edi
    pop esi
    pop edx
    pop ebx

    ret