[parisc-linux] enumerating devices from user space

[Matthew Wilcox]

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.

-- 
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