Information processing apparatus

A computer system comprising:

• first main memory,
• non-volatile storage storing a first configuration second configuration information of said first main memory and information of a second main memory to be hot-added, and
• a processor acquiring said first and second configuration information from said non-volatile storage on memory-mapping of said first main memory, said processor being capable of accessing said non-volatile memory before initialization of an I/O device;
• wherein said first memory includes a region not subject to address translation and wherein said processor stores first logical-physical address translating pairs of said first memory in said region not subject to address translation.

A computer system, which supports a virtual memory system, said computer system comprising:

• a first main memory,
• a non-volatile storage storing a first information setting a memory size of a second main memory to be hot-inserted,
• a processor mapping said first main memory and acquiring said first information upon said mapping, said processor being capable of accessing said non-volatile memory before initialization of an I/O device;
• wherein said first memory includes a region not subject to address translation and wherein said processor stores first logical-physical address translating pairs of said first main memory in said region not subject to address translation.