Last step of CMD_COMPLETE_STEPS includes INTSTAT_SO to indicate to CurioSCSIController::fsmCompleting that it returned both a status byte and a message byte in the FIFO.
- For pdm/amic, real_dma_xfer is called when SCSI_DMA_Ctrl has the run bit set.
- For tnt/grandcentral, dma_wait is called when the DBDMA is started (run bit is set). It will call real_dma_xfer when the phase and sequence are DATA_IN/RCV_DATA or DATA_OUT/SEND_DATA.
- dma_wait and real_dma_xfer uses a one shot timer instead of a loop to continue doing DMA while also giving time to the CPU. This and the above changes handles the case where the DBDMA is started before setting up the transfer phase and sequence.
- dma_stop will stop the one shot timer when the DBDMA channel is stopped.
bytes_out is used instead of the removed cur_buf_cnt.
data_ptr is setup by prepare_data instead of process_command.
Not sure why scsicdrom doesn't set bytes_out in prepare_data.
- Use macros for reading 2 byte or 4 byte big endian data. block_size is assumed to be < 64K so WRITE_DWORD_BE_A will write two leading zeros.
- Scalar pass by value parameters don't need to be const.
- Remove some unnecessary locals.
Make it a separate method like scsihd. It also checks the incoming param size. If it's zero then the phase is not switched. Is that wrong? Still probably unfinished.
The total size needs to have 3 factors cylinders, heads, & sectors. Imagine a disk having a total size with 3 prime factors 3 x 5 x 11. 15 cannot be assigned to heads because that would only leave 11 for sectors and cylinders. Therefore, test all heads and sectors combinations. If the third factor for cylinders is not found, then choose 16 heads, then the minimum number of sectors, and finally the maximum number of cylinders. The loop could be changed to skip values of heads that are not a factor, but it doesn't take any time to try them all.
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For pseudo_dma_read report FIFO underrun and init data_word in that case.
