Re: Request for help

Re: Request for help

[Eric W. Biederman]

I am CC'ing linux-kernel as that is the general kernel list.  There
may be something even more focused on IDE issues but I am
not aware of it.

"ganesh_borse" <ganesh_borse@indiatimes.com> writes:

> Hi,
> 
> 
> I would like to request for a little help related to IDE controllers.
> 
> 
> I am trying to develop a device drive code for listing the devices connected to
> a ide controller at the time of kernel booting.
> 
> 
> 
> Is there any way to get which channels on ide controller has got devices and
> which devices? 

Yes.  But it is baroque.

> This I am trying to get even before the normal ide device driver
> has been setup. Are there ide controller commands to get this info? 

Not exactly.  The method is essentially you ping the drives to see
if they are there.

> Or is this
> info stored in registers of ide-controllers? 

Nope this information is not stored in registers.

> For this do we need to write
> assembly instructions on linux?

No.

But there is also nothing that allows you to force the module
order within the kernel.  So there are no guarantees you will
come before a normal IDE driver.  I assume from the questions
you intend to have this working in the linux kernel.

Eric

Re: Request for help

[Andy Pfiffer]

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On Mon, 2003-06-02 at 10:49, Eric W. Biederman wrote:
> "ganesh_borse" <ganesh_borse@indiatimes.com> writes:
...
> > I am trying to develop a device drive code for listing the devices connected to
> > a ide controller at the time of kernel booting.
...
> > Is there any way to get which channels on ide controller has got devices and
> > which devices? 
> 
> Yes.  But it is baroque.
> 
> > This I am trying to get even before the normal ide device driver
> > has been setup. Are there ide controller commands to get this info?

If you can wait until *after* the system has booted, there are lots of
ways to derive what is out there.  Grab the sources for "hdparm" and
have a look at it for examples of hardcore access methods.

A simple way to derive some information can be found by walking the
sysfs hierarchy.

Here's a dirt-simple script I use that somewhat-pretty-prints items
hanging off busses in the sysfs hierarchy.  Sysfs must be mounted for
the script to work.

Sample output:
% lsbus
ide:
  pci0/00:1f.1/ide1/1.0 [ IDE Drive ]
  pci0/00:1f.1/ide0/0.1 [ IDE Drive ]
  pci0/00:1f.1/ide0/0.0 [ IDE Drive ]

ide-scsi:

pci:
  pci0/00:1e.0/04:04.0 [ Intel Corp. 82557/8/9 [Ethernet  ]
  pci0/00:02.0/02:1f.0/03:00.0 [ Intel Corp. 82806AA PCI64 Hub Ad ]
  pci0/00:02.0/02:1f.0 [ Intel Corp. 82806AA PCI64 Hub PC ]
  pci0/00:01.0/01:00.0 [ Matrox Graphics, Inc MGA G400 AGP ]
  pci0/00:1f.5 [ Intel Corp. 82801BA/BAM AC'97 Au ]
  pci0/00:1f.3 [ Intel Corp. 82801BA/BAM SMBus ]
  pci0/00:1f.2 [ Intel Corp. 82801BA/BAM USB (Hub ]
  pci0/00:1f.1 [ Intel Corp. 82801BA IDE U100 ]
  pci0/00:1f.0 [ Intel Corp. 82801BA ISA Bridge ( ]
  pci0/00:1e.0 [ Intel Corp. 82801BA/CA/DB PCI Br ]
  pci0/00:02.0 [ Intel Corp. 82860 860 (Wombat) C ]
  pci0/00:01.0 [ Intel Corp. 82850 850 (Tehama) C ]
  pci0/00:00.0 [ Intel Corp. 82860 860 (Wombat) C ]

platform:
  legacy/floppy0 [ Floppy Drive ]

pnp:
  pnp0/00:10 [ 16550A-compatible COM port ]
  pnp0/00:0f [ ECP printer port ]
  pnp0/00:0d [ PC standard floppy disk controller ]
  pnp0/00:0c [ 16550A-compatible COM port ]
  pnp0/00:0b [ PS/2 Port for PS/2-style Mice ]
  pnp0/00:0a [ PCI Bus ]
  pnp0/00:09 [ Reserved Motherboard Resources ]
  pnp0/00:08 [ System Board ]
  pnp0/00:07 [  ]
  pnp0/00:06 [ Math Coprocessor ]
  pnp0/00:05 [ AT-style speaker sound ]
  pnp0/00:04 [ IBM Enhanced (101/102-key, PS/2 mouse support) ]
  pnp0/00:03 [ AT Real-Time Clock ]
  pnp0/00:02 [ AT Timer ]
  pnp0/00:01 [ AT DMA Controller ]
  pnp0/00:00 [ AT Interrupt Controller ]

scsi:

system:
  sys/rtc0 [ i8253 Real Time Clock ]
  sys/timer0 [ timer ]
  sys/pic0 [ i8259A PIC ]
  sys/cpu1 [ CPU 1 ]
  sys/cpu0 [ CPU 0 ]

usb:
  pci0/00:1f.2/usb1/1-0:0 [ Hub ]
  pci0/00:1f.2/usb1 [ Intel Corp. 82801BA/BAM USB (Hub (Linux 2.5.70 uh
]
%

The script is attached...




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#!/bin/sh

#
#	$Id$
#
#	andyp@osdl.org
#

mnt=`grep sysfs /proc/mounts | awk '{print $2}'`
cd $mnt

if [ $# = 0 ]; then
	cd ./bus
	buslist=`echo *`
	cd ..
else
	buslist="$*"
	cd ./bus
	for bus in $buslist; do
		if [ ! -d $bus ]; then
			echo "$bus: unknown bus"
			exit 1
		fi
	done
	cd ..
fi

for bus in $buslist; do
	cd ./bus
	if [ -d $bus ]; then
		echo "$bus:"
		cd $bus
		if [ -d ./devices ]; then
			cd ./devices
			devs=`find . -type l -printf "%l\n"`
			for dev in $devs; do
				name=""
				if [ -d $dev ]; then
					if [ -f $dev/name ]; then
						name=`cat $dev/name`
					fi
				fi
				terse=`echo $dev|sed -e 's/\.\.\/.*devices\///'`
				echo "  $terse [ $name ]"
			done
			cd ..
		fi
		cd ..
		echo
	fi
	cd ..
done