Romsegmentet

romsegmentet is a term used to describe the portion of a computer system’s memory that is designated for read-only memory. This memory region stores firmware and other non-volatile code and data that must persist across power cycles and typically remains unchanged during normal operation. In practice, a romsegmentet can be implemented as physical ROM or as flash memory configured to behave as read-only most of the time, with special procedures allowing updates.

Historically, in architectures that use segmented memory, such as the Intel 8086 family, a ROM segment referred to a fixed area of the address space where firmware could reside. In x86 PC systems, for example, the BIOS and other firmware often occupied a high, fixed region of memory (the conventional ROM area near the top of the 1 MB address space). This arrangement ensured that essential code used during boot and hardware initialization remained accessible and protected from regular memory writes.

In modern systems, firmware often resides in flash memory, which is non-volatile and can be updated through controlled procedures. The romsegmentet concept remains important for bootstrapping, hardware initialization, and maintaining a trusted baseline of code. While the hardware and storage technology may evolve, the idea of a dedicated, durable region for firmware continues to play a central role in system design and security.

See also: firmware, BIOS, boot ROM, flash memory, memory mapping.