Developer Manual/I2C
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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 https://doc.coreboot.org/. Contributions welcome!
Introduction
SMBUS and I2C are closely related buses. The SPD (Serial Presence Detect) of the DIMM's are I2C devices that need to be read during RAM initialisation.
For characterizing I2C on a unsupported motherboard I used the following tools:
- sensors-detect (lm-sensors)
- i2cdetect
- i2cdump
Using this tools on a normal bios on the motherboard its easy to identify the appropriate address for the SPD data.