1497 mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
1498 Amount of memory to be used when the kernel is not able
1499 to see the whole system memory or for test.
1500 [X86] Work as limiting max address. Use together
1501 with memmap= to avoid physical address space collisions.
1502 Without memmap= PCI devices could be placed at addresses
1503 belonging to unused RAM.