Re: Loading a compressed root fs to ramdisk

Benjamin Close (linux@senet.com.au)
Thu, 18 Feb 1999 10:32:53 +1030 (CST)


On Wed, 17 Feb 1999, Frank T. Kujawski wrote:

> I am trying to build a two disk boot system. I feel that the problem is
> with the kernel loading a compressed filesystem. This is what I know.
> 1) Boot RH52/rescue and it loads my compressed disk
> 2) Boot my kernel and it loads my uncompressed disk
> 3) I am using kernel "linux-2.0.36"
> 4) Boot my kernel and it can not find any file system on my
> compressed disk
> 5) /usr/src/linux/.config
> #
> # Additional Block Devices
> #
> # CONFIG_BLK_DEV_LOOP is not set
> # CONFIG_BLK_DEV_MD is not set
> CONFIG_BLK_DEV_RAM=y
> CONFIG_BLK_DEV_INITRD=y
> # CONFIG_BLK_DEV_XD is not set
> # CONFIG_PARIDE is not set
> # CONFIG_BLK_DEV_HD is not set
> I am sure there is a simple solution, but it currently eludes me.
>

Your problem is you have to tell the kernel that the rootfs is compressed.
Ie:
bits 0-10: Offset to start of ramdisk, in 1024 byte blocks
bits 11-13: unused
bit 14: Flag indicating that ramdisk is to be loaded
bit 15: Flag indicating to prompt before loading rootfs

To use this:
rdev -r kernelgoeshere valueascalculated

Read the Bootdisk-HOWTO for a more detailed description.

Cheers

--

* Benjamin Close * Benjsc@senet.com.au * Web Page: http://users.senet.com.au/~benjsc

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