>>> From: "Romanowski, John (OFT)" <[email protected]>
> Bottom of p34 (pdf p48) of SLES11 Device Drivers manual says 'you can
speci=
> fy =1B$B!m=1B(Bdiag=1B$B!m=1B(B on the command line, for example during
IPL=
> ,
> to force the device driver to access the device (range) using the DIAG
acce=
> ss method.'
>
> Sounds like it's saying (erroneously?) 'dasd=3D...(diag)' is supported on
t=
> he kernel command line.
>
> But that SLES11 manual has no other mention of configuring the dasd
driver =
> via kernel command line parameters unlike the pre-SLES11 editions that
deta=
> iled how to do that.
>
When a device driver is compiled into the kernel image file (CONFIG_DASD=y)
then driver options can be passed to it directly from the kernel command
line
parameters. When the driver is compiled as a loadable kernel module
(CONFIG_DASD=m) then it gets passed driver options when the module is
loaded,
ex:
insmod dasd_mod.ko dasd=100-105
The kernel parameters though can be consumed by stuff other than the
kernel.
For example, with installation images for System z you can pass network
parameters and such that get parsed by the linuxrc script on the initrd.
Otherwise you normally get prompted by linuxrc during the installation to
give values to these.
On SLES10 "dasd=" could be passed in via the kernel parameters and consumed
later by the boot scripts that loaded the dasd_mod driver. With SLES11
this
is no longer an option. Instead, if module parameters need to be
specified,
the standard modprobe.conf mechanism is available and supported. For that
an options statement may be added in /etc/modprobe.conf.local to change
default load options used when loading a device driver. Changing
the .local
file is preferred since /etc/modprobe.conf itself is subject to
modification
by system updates and such. Additional steps (ex: mkinitrd/zipl) may be
needed to make sure any modprobe.conf changes make it into the initial
ramdisk used for booting the system.
- Mark Ver
office: Building 710 / Room 2-RF-10
phone: (845) 435-7794 [tie 8 295-7794]
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