| Entry | |
|---|---|
| R0 | Configuration space address (0-255) or bus/dev/fn/address |
| R2 | Access size (1, 2 or 4 for byte/half word/word) |
| R3 | Function handle, or 0 |
| Exit | |
|---|---|
| R0 | Preserved ? |
| R1 | Value read |
| R2 | Preserved ? |
| R3 | Preserved ? |
The purpose of this call is to perform a Configuration Read cycle of the denoted size.
PCI_ConfiurationWrite? is used to perform a Configuration Write cycle of the denoted size.