Re: [PATCH v15 03/11] esp: add pseudo-DMA as used by Macintosh

On 26/10/19 18:45, Laurent Vivier wrote: > There is no DMA in Quadra 800, so the CPU reads/writes the data from the > PDMA register (offset 0x100, ESP_PDMA in hw/m68k/q800.c) and copies them > to/from the memory. > > There is a nice assembly loop in the kernel to do that, see > linux/drivers/scsi/

[PATCH v15 03/11] esp: add pseudo-DMA as used by Macintosh

There is no DMA in Quadra 800, so the CPU reads/writes the data from the PDMA register (offset 0x100, ESP_PDMA in hw/m68k/q800.c) and copies them to/from the memory. There is a nice assembly loop in the kernel to do that, see linux/drivers/scsi/mac_esp.c:MAC_ESP_PDMA_LOOP(). The start of the tran