258

Hard Disk Arguments

The hard disk arguments are used to do special setup on IDE devices. This

includes a number of CD ROM devices as well as the normal hard drives.

Drive specific options have the form:

hda=, hdb=, hdc=, hdd=.

Non drive specific options have the form: hd=. This option can be used to

specify the next drive in the a, b, c, d order. Drive specific options can be

used in place of non specific ones with the expected result. In the following

discussion the hd= will be used exclusively and can be replaced by any drive

specific option that applies.

hd=cyls,heads,sects[,wpcom[,irq]]

This option is used to specify the physical geometry of

the disk. Only the first three parameters are required.

The wpcom (write pre compensation) parameter is

ignored by IDE devices. The irq value is the irq of the

controller of the device and as such is not strictly a drive

parameter.

hd=serialize

Many of the older kernels had a broken CMD 640 chip

driver design which resulted in corrupted data when

the second controller was operated at the same time as

the first. This option forces the driver to do sequential

accesses rather than simultaneous activity. You will only

need to use this option if you have a drive installed on

the second IDE controller.