On standard PCs it looks like adoption of the LPC bus is growing.
When the LPC bus is present there are currently two ROM standards.
1) Intel 8xx chipsets support intel firmware hubs.
   Intel & SST make compatible parts, and these go up in size to 1Mx8.
   Given that this is pretty intel specific and roms exist that do
   not need special support I suspect eventually firmware hubs
   will disappear.
2) LPC roms.
   Currently these are small devices 256Kx8.  And it looks like
   it will be that way for a while.  Their address on the LPC bus
   is hard coded but there are plenty of extra pins in a standard 
   32bit PLCC package to allow the ROM address to be selectable.

So for the short term the 256KB limit on rom sizes remains important
to handle.  In the long term with the adoption of the LPC bus there is
no technical reason why rom chips must be small. 

Since we have to suffer the pain of getting a small bootloader built
up there is one advantage to recall.  Flash chips are _slow_ so the
smaller the bootloader the less we have to read from the flash chip,
the faster we will go :)

Eric

Reply via email to