Re: [Etherboot-developers] Q: USE_LOWMEM_BUFFER?

[Eric W B. <ebi...@ln...>]

ke...@us... (Ken Yap) writes:

> >I'm a little curious about the history of USE_LOWMEM_BUFFER, and
> >the reasons for it.  The primary reason is that when I start
> >compiling I can easily get a huge .bss section, because all of the
> >drivers have a seperate transmit buffer.
> >
> >I'm not advocating reviving USE_LOWMEM_BUFFER but instead looking
> >at what it would take to use the old USE_LOWMEM_BUFFER infrastructure
> >to have a common transmit buffer.
> 
> USE_LOWMEM_BUFFER is a hack that Klaus Espenlaub created for some 4.x
> drivers because at that time Etherboot only had 32kB-- from 0x98000
> upwards. In 5.x by refining mknbi and juggling the segments around I
> gave Etherboot 48kB-- from 0x94000 upwards, obviating the need for
> USE_LOWMEM_BUFFER which I thought was ugly.
> 
> It would probably be better to rework the means by which drivers get
> buffers, possibly by providing a library which returns pointers to a
> common buffer area. Then the decision where to put the buffer area is
> concentrated in the library, not scattered throughout drivers.

Sounds good.  But USE_LOWMEM_BUFFER is useful in point out what areas 
need to be changed.

Eric