Configuration Storage

There are two places where you may want to consider using a registry +to hold information for DMA.

Chipset +configuration

On initialization of the chipset you can store +and retrieve settings in the HCR.

In the DMA Implementation +Guide there are links to a sample implementation in which no +chipset configuration is required or specified.

Channel +configuration and information

When a client opens a channel, +it specifies a cookie parameter in the DmaChannelMgr::Open() function. This cookie is used by the DMA implementation to identify +a specific channel on a specific DMA controller. This is entirely +chipset and implementation specific and the client will need to know +what cookie values can be used to request a channel.

One way +that the implementation can communicate this information to the client +is by using the Central Repository to hold a table of cookie values +and matching channel identification. An alternative approach may be +to use a Central Repository entry to specify the number of channels +available and then the client knows the highest channel number it +can request.

Again this is entirely implementation specific. +In the implementation mentioned above, the repository is not used.