Re: [ros-dev] Development plans for May

aicommander wrote:
[...]
>  The main problem with NDIS 5.1 drivers is the lack of
> S/G support in  
HAL
>   (PRO/100 and PRO/1000 XP drivers are affected by
> this). 
Could the follwing info from public MSDN help? If so, it seems to be a 
rather minor hack to make it work:

Scatter/gather DMA
    Scatter/gather DMA is a shortcut method that sets up several 
packet DMA transfers at once. If you are transferring a packet over the 
network, for example, each part of the network stack adds its own 
header (TCP, IP, Ethernet, and so forth). These headers are all 
allocated from different places in memory. In this case, the 
scatter/gather DMA saves time by issuing a batch request to the HAL to 
map each header plus the data segment for access by the hardware. 
Instead of having to call the packet DMA routines on each part of the 
packet, this method calls each routine once, and lets the HAL be 
responsible for mapping each one individually.

    Note  Scatter/gather capability does not mean that the device can 
use the scatter/gather routines. Scatter/gather capability refers to a 
flag in the device description that indicates that the device is able 
to read or write from any area in memory, instead of just a certain 
range.

--------

What I found to be the interesting (and easily hackable) part was "and 
lets the HAL be responsible for mapping each one individually".

-- 
Mike