On 12/13/2005, "Izumi Tsutsui" <tsutsui@ceres.dti.ne.jp> wrote:

>BTW, where does this 0x800000 come from?
>Hardware (crime) limitation?
>Or software boundary to store kernel into the lower 8MB region?

Apparently all DMA buffers must be above 8MB, per Jeff Smith's
explanation of the IRIX workarounds.

>This is bus_dmamem_map(9). Only some DMA descriptors are handled
>by this function. In bus_dmamap_load_buffer(), any KVA buffers
>could be used for DMA ops unless you prepare the bounce buffer.

Thanks for that, I'll take a look at it.

-- Chris