Action name: ManualRegionsThis command open a window with manual memory regions. In this window the user can manipulate memory region definitions: add or delete them.
Some debugger backends (e.g. the gdb backend) do not provide memory layout information. IDA needs this information in order to show the memory contents. When this information is not available, the user must specify it.
The defined memory regions will be accessible when the debugger is active. The user will be able to see the memory contents in the disassembly windows.
If no memory information is provided by the user nor by the debugger backend, IDA will assume that entire memory space is accessible. However, it is better to specify memory layout more precisely.
See also Debugger submenu.