Difference between revisions of "Developer Manual"

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(→‎RAM init: - added Micron SPD lookup link)
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:Whether the Super I/O is at config address ''0x2e'' (the usual case) or ''0x4e'' (or some other address) is mainboard-dependent. You can find out the address by running [[superiotool]].
:Whether the Super I/O is at config address ''0x2e'' (the usual case) or ''0x4e'' (or some other address) is mainboard-dependent. You can find out the address by running [[superiotool]].


v2: Sometimes you need to setup virtual LDN for Config.lb. Check [[SuperIO_port_guide]]
=== Virtual logical devices ===
 
Some Super I/Os use register 0x30 of one logical device number (LDN) for more then one function enable. For example, it can be used to enable some GPIOs, GAME, MIDI etc. To overcome this issue a concept of virtual LDN has been introduced. Virtual LDNs can be used in coreboot to map the enable bit position in register 0x30 to virtual LDN, which will just enable the functionality map to that bit.
 
Original LDN always just switch on or off bit0 of register 0x30. Virtual LDN is created as follows.
Low [7:0] bits are used to describe the original LDN. High [10:8] bits select the position of the bit enable in the register 0x30.
 
If LDN is 0x7 it will handle bit0 of register 0x30. If the (virtual) LDN is 0x107 it will handle bit1 of same register etc.


== Northbridge ==
== Northbridge ==

Revision as of 11:26, 17 November 2008