Developer Manual/Memory map

The wiki is being retired!

Documentation is now handled by the same processes we use for code: Add something to the Documentation/ directory in the coreboot repo, and it will be rendered to Contributions welcome!

This page contains the description of various memory areas important for coreboot development.

Physical memory properties

Below 1MB

All memory below 1 MB has special rules attached to it. Due to legacy reasons, you can't allocate memory freely in that area without taking care.

Above 1MB

Some southbridges will restrict initial ROM mapping size to 1 MB or less. Some southbridges can't support more than 1MB or 4 MB. Some southbridges allow you to map the ROM anywhere.

coreboot related settings/usage