[parisc-linux] enumerating devices from user space

[Lyonel Vincent]

many thanks for the prompt answer

well... that's exactly the answer I didn't want to ear ;o)
lshw can't reasonably assume that /var/log/dmesg exists and is correct (or
even dmesg) and dig into the trash.

My kernel programming skills are extremely limited (not to say inexistent) but
how difficult would it be to expose this information to user space through
/proc? (AFAICT, we already have PA-RISC specific files like /proc/bus/runway)
A simplistic format like <hwpath>\t<type> <instance> <hversion> <sversion> etc.
would do.
Do you think it'd be useful to make that kind of information available to user-
space? (besides lshw of course ;op) If it's the case I'll try to do my best...

cheers,
lv.

On Wed, Mar 12, 2003 at 04:48:52PM +0000, Matthew Wilcox wrote:
> On Wed, Mar 12, 2003 at 05:32:36PM +0100, Lyonel Vincent wrote:
> > I'm currently implementing a small tool called lshw (you can find it on
> > Freshmeat) that enumerates installed devices on a machine and reports them
> > as a device tree (text, HTML and XML).
> 
> That's cool.
> 
> > For now it knows about DMI, PCI busses, SCSI, IDE and PCMCIA and I would
> > like to port it to PA-RISC Linux. I already get some very basic info from
> > /proc/cpuinfo.
> > Does anyone know how I can access the device tree as seen by the kernel?
> > (much like HP-UX's ioscan does and what is shown in dmesg)
> 
> You can look in /var/log/dmesg.  For example...
> 
> Found devices:
> 1. U2-IOA BC Runway Port (12) at 0xfff88000 [8], versions 0x580, 0xf, 0xb
> 2. Dino PCI Bridge (13) at 0xf2000000 [8/0], versions 0x680, 0x0, 0xa,  additional addresses: 0xf2800000 
> 3. Raven U/L2 Dino PS/2 Port (10) at 0xf2001000 [8/1], versions 0x6, 0x0, 0x96
> 4. Raven U/L2 Dino RS-232 (10) at 0xf2003000 [8/3], versions 0x6, 0x0, 0x8c
> 5. Raven U/L2 Core FW-SCSI (4) at 0xf200c000 [8/12], versions 0x3b, 0x0, 0x89
> 6. Raven U/L2 Core BA (11) at 0xffd00000 [8/16], versions 0x3b, 0x0, 0x81,  additional addresses: 0xffd0c000 0xffc00000 
> 7. Raven U/L2 Core Centronics (10) at 0xffd02000 [8/16/0], versions 0x3b, 0x0, 0x74,  additional addresses: 0xffd01000 0xffd03000 
> 8. Raven U/L2 Core Audio (10) at 0xffd04000 [8/16/1], versions 0x3b, 0x4, 0x7b
> 9. Raven U/L2 Core RS-232 (10) at 0xffd05000 [8/16/4], versions 0x3b, 0x0, 0x8c
> 10. Raven U/L2 Core SCSI (10) at 0xffd06000 [8/16/5], versions 0x3b, 0x0, 0x82
> 11. Raven U/L2 Core LAN (802.3) (10) at 0xffd07000 [8/16/6], versions 0x3b, 0x0, 0x8a
> 12. Raven U/L2 Core PS/2 Port (10) at 0xffd08000 [8/16/7], versions 0x3b, 0x0, 0x84
> 13. Raven U/L2 Core PS/2 Port (10) at 0xffd08100 [8/16/8], versions 0x3b, 0x0, 0x84
> 14. Raven Backplane Wax BA (11) at 0xffe00000 [8/20], versions 0x17, 0x0, 0x8e
> 15. Raven Backplane Wax HIL (10) at 0xffe01000 [8/20/1], versions 0x17, 0x0, 0x73
> 16. Raven Backplane RS-232 (10) at 0xffe02000 [8/20/2], versions 0x17, 0x0, 0x8c
> 17. Raven Backplane Wax EISA BA (11) at 0xfc000000 [8/20/5], versions 0x17, 0x0, 0x90,  additional addresses: 0xffc88000 0xfc00000b 
> 18. Gecko GSC Core Graphics (10) at 0xfa000000 [8/24], versions 0x16, 0x0, 0x85,  additional addresses: 0xf0026000 
> 19. U2-IOA BC GSC+ Port (7) at 0xf203f000 [8/63], versions 0x501, 0x1, 0xc
> 20. U2-IOA BC Runway Port (12) at 0xfff8a000 [10], versions 0x580, 0xf, 0xb
> 21. U2-IOA BC GSC+ Port (7) at 0xf103f000 [10/63], versions 0x501, 0x1, 0xc
> 22. Raven U 240 (9000/780/C240) (0) at 0xfffa0000 [32], versions 0x599, 0x0, 0x4
> 23. Memory (1) at 0xfffb1000 [49], versions 0x6f, 0x0, 0x9
> 
> The numbers in [] tell you what the tree looks like.  In this example, we
> have 4 top-level devices: #1, #20, #22 & #23.
> 
> > I've tried digging in /proc without much success... is there a way to get
> > this information from user space? PPC Linux exposes the device tree in
> > /proc for example. A mechanism similar to /proc/bus/pci/devices (machine-
> > parseable text) would be great, too.
> 
> In 2.5, this information's available via sysfs.  I don't think we'll
> expose it in /proc.
> 
> > PS: I noticed that /proc/iomem lists 00000000-000009ff as "PDC data (Page
> > Zero)", is there a chance I can find what I need there? (I dd-ed it from
> > /dev/mem but I can't say if it contains useful data...)
> 
> No, you need to actually make firmware calls and you can't do that from
> user mode.
> 
> -- 
> "It's not Hollywood.  War is real, war is primarily not about defeat or
> victory, it is about death.  I've seen thousands and thousands of dead bodies.
> Do you think I want to have an academic debate on this subject?" -- Robert Fisk

-- 
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