[Linux-ia64] disabling nics using boot options.

[Linux-ia64] disabling nics using boot options.

[Roy Dragseth]

Hello again.

Thanks for all the nice answers to my previous question about disabling 
interfaces with efi.

As it seems to be impossible to disable the NICs in hardware, I want to try to 
make the linux kernel avoid probing the devices by using the reserve= boot 
option.  The problem is that I am unable to figure out the right parameters 
for the Gbit NIC because /proc/pci doesn't contain any iobase information for 
this device.


I found an example in the BOOTPROMPT-HOWTO, 
http://www.ibiblio.org/mdw/HOWTO/BootPrompt-HOWTO-3.html#ss3.4
and it works for the 10/100Mbit interface using the eepro100 module.

Here are what /proc/pci and /proc/iomem says about the relevant devices:

/proc/pci:
  Bus  0, device   3, function  0:
    Ethernet controller: Intel Corp. 82557/8/9 [Ethernet Pro 100] (rev 13).
      IRQ 53.
      Master Capable.  Latency=128.  Min Gnt=8.Max Lat=56.
      Non-prefetchable 32 bit memory at 0x80020000 [0x80020fff].
      I/O at 0xd00 [0xd3f].
      Non-prefetchable 32 bit memory at 0x80000000 [0x8001ffff].
  Bus 32, device   2, function  0:
    Ethernet controller: BROADCOM Corporation NetXtreme BCM5701 Gigabit 
Ethernet (rev 21).
      IRQ 56.
      Master Capable.  Latency=192.  Min Gnt=64.
      Non-prefetchable 64 bit memory at 0x90800000 [0x9080ffff].
  Bus 128, device   1, function  0:
    Ethernet controller: BROADCOM Corporation NetXtreme BCM5701 Gigabit 
Ethernet (#2) (rev 21).
      IRQ 65.
      Master Capable.  Latency=192.  Min Gnt=64.
      Non-prefetchable 64 bit memory at 0xc0000000 [0xc000ffff].

As one can see, the entry for the Ethernet Pro 100 nic has a line
      I/O at 0xd00 [0xd3f].
so the the reserve entry becomes 0xd00,64.  This works as expected, the device 
doesn't show up when I boot with 
  reserve=0xd00,64
However, the entries for the Gbit interfaces don't have this information, do 
anyone know where I should look for the parameters for these devices?



r.

-- 

  The Computer Center, University of Tromsø, N-9037 TROMSØ, Norway.
	      phone:+47 77 64 41 07, fax:+47 77 64 41 00
     Roy Dragseth, High Performance Computing System Administrator
	 Direct call: +47 77 64 62 56. email: royd@cc.uit.no

Re: [Linux-ia64] disabling nics using boot options.

[Roy Dragseth]

Further investigation shows that if I connect the Gbit interface to a 10Mbs 
hub everything works ok, e.g. using the ksdevice=eth2 boot option works as 
expected.

I have narrowed this down to the following problem:  When the init process 
tries to configure the eth2 with dhcp it fail, but if I logon as root and run

/etc/init.d/network start

everything works ok.  Subsequent reboots also works ok because now the 
information is cached in /etc/dhcpc/.  If I remove the cached info the 
problem turn up again.

Do anyone know what could be different between init running the network start 
and when root does it?

r.