Compaq Evo 510 PC & DMA

Vittorio vdemart1 at
Thu Nov 3 17:03:47 GMT 2005

Some time ago I had posted a problem I was suffering trying to install 
freebsd 5.4 on a Compaq evo 510 PC. The boot immediatedly stopped with 
weird indications on the causes. Freesbie also failed. Surfing the net 
I understood that the problem with that specific PC was already known 
and no real solution was proposed.
Today I came across http://www. in which it was suggested that 
CPU: 2.8 GHz P4; 1024MB RAM; i810 Intel integrated NIC (recognized 
as EEPro100); i845 Intel integrated video...FreeBSD 5.1 loads, but only 
after DMA is disabled in BIOS.  

In fact, disabling the bios dma I was 
able to start both freesbie and the 5.4 installation CD!

Not being a 
PC expert but knowing that dma is useful to significantly reduce the 
load of the CPU when I/O operations are in progress and my question is:

Having disabled the bios dma, Is dma (re-)enabled all the same in some 
way by freebsd 5.4  when it boots OR  will I have a "crippled" system 
at my disposal?

Take into account that the pc will work as a 
postgresql server.


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