- Read 8 bytes at a time instead of just 1.
- Remove multiply operations from loop. We just need increments or additions.
- Change compares with int to compares with zero.
CUR_HORZ_OFF becomes non-zero when the cursor needs to be drawn to the left of the left edge of the frame buffer.
CUR_VERT_OFF is handled differently. When CUR_VERT_OFF is non-zero, CUR_OFFSET is changed to point to the first line of the cursor that will be drawn, so CUR_VERT_OFF is the number of lines to remove from the total height of the cursor.
Alternatively, we could handle CUR_VERT_OFF the same way as CUR_HORZ_OFF by leaving the cursor height constant, drawing the cursor starting from the CUR_VERT_OFF line, and adjusting cursor Y position by negative CUR_VERT_OFF.
This method is used by both pci_io_read and pci_io_write to determine if ISA type I/O access is allowed.
The SPARSE_IO_BASE I/O address is defined. This I/O range is not defined by an I/O BAR.
While dingusppc only emulates 32-bit Macs (for now), it is possible for a 32-bit Power Mac to use a PCIe card that has 64-bit BARs.
finish_config_bars is added to scan the cfg values of the BARs and determine their type. The type is stored separately so that it does not need to be determined again.
The type can be I/O (16 or 32 bit) or Mem (20 or 32 or 64 bit). A 64 bit bar is two BARs, the second contains the most significant 32 bits.
set_bar_value uses the stored type instead of trying to determine the type itself. It is always called even when the firmware is doing sizing. For sizing, It does the job of setting the bar value so do_bar_sizing is now just a stub.
Every PCIDevice that has a BAR needs to call finish_config_bars after setting up the cfg values just as they need to setup the cfg values. Since they need to do both, maybe the cfg values should be arguments of finish_config_bars, then finish_config_bars() should be renamed config_bars().
