Memory map

A hypothetical memory map of bank-switched memory for a processor that can only address 64 kB. This scheme shows 200 kB of memory, of which only 64 kb can be accessed at any time by the processor. The operating system must manage the bank switching operation to ensure that program execution can continue when part of memory is not accessible to the processor.

In computer science, a memory map is a structure of data (which usually resides in memory itself) that indicates how memory is laid out. Memory maps can have a different meaning in different parts of the operating system.

In the boot process, a memory map is passed on from the firmware in order to instruct an operating system kernel about memory layout. It contains the information regarding the size of total memory, any reserved regions and may also provide other details specific to the architecture.

In virtual memory implementations and memory management units, a memory map refers to page tables, which store the mapping between a certain process's virtual memory layout and how that space relates to physical memory addresses.

In native debugger programs, a memory map refers to the mapping between loaded executable/library files and memory regions. These memory maps are used to resolve memory addresses (such as function pointers) to actual symbols.

See also

• BIOS
• RAMMap by Mark Russinovich