Intel 82801EB Programmer's Reference Manual page 50

Theory of Operation
Method( CTYP, 1)
{
Store( Zero, Local0)
If( Arg0)
{
}
Else {
50
//
// Check the Primary Channel
//
// Check if combined mode and if this device is a P-ATA
// device MAP == 100b or 101b Combined mode, P-ATA is
// secondary
//
If( LAnd( LGreater( MAP, 0x1), LLess( MAP, 0x6)))
{
Store( 0x1, Local0) // SATA is primary, combined
}
Else {
If( LEqual( MAP, Zero))
{
Store( 3, Local0) // port 0 is primary master
}
If( LEqual( MAP, One)
{
Store( 4, Local0) // port 1 is primary master
}
}
//
// Check the secondary Channel
//
// Check if combined mode and if this device is a P-ATA
// device MAP == 110b or 111b Combined mode, P-ATA is
// primary
//
If( LGreater( MAP, 0x5))
{
Store( 0x2, Local0) // SATA is Secondary, combined
}
Else {
If( LEqual( MAP, Zero))
{
Store( 5, Local0) // port 0 is secondary master
}
SATA Programmer's Reference Manual
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