Messages in this thread Patch in this message |  | | Date | Mon, 3 Feb 1997 20:31:55 -0801 (PST) | From | Trevor Johnson <> | Subject | Re: kernel too big? |
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I tried updating Documentation/initrd.txt:
--- linux/Documentation/initrd.txt.orig Thu Apr 11 23:49:09 1996 +++ linux/Documentation/initrd.txt Mon Feb 3 20:25:55 1997 @@ -1,20 +1,17 @@ -Using the initial RAM disk (initrd) -=================================== +Using the initial RAM disk, initrd +================================== -Written 1996 by Werner Almesberger <almesber@lrc.epfl.ch> and - Hans Lermen <lermen@elserv.ffm.fgan.de> +by Werner Almesberger <almesber@lrc.epfl.ch> and +Hans Lermen <lermen@elserv.ffm.fgan.de> -initrd adds the capability to load a RAM disk by the boot loader. This -RAM disk can then be mounted as the root file system and programs can be -run from it. Afterwards, a new root file system can be mounted from a -different device. The previous root (from initrd) is then either moved -to the directory /initrd or it is unmounted. - -initrd is mainly designed to allow system startup to occur in two phases, -where the kernel comes up with a minimum set of compiled-in drivers, and -where additional modules are loaded from initrd. - +The initrd feature allows the boot loader to load a RAM disk. This RAM +disk can then be mounted as the root file system and programs can be run +from it. Afterwards, a new root file system can be mounted from a +different device. The previous root (from initrd) is then usually either +moved to the directory /initrd or unmounted. With this technique, drivers +for the "normal" root file system can be stored on the RAM disk as +modules. Operation --------- @@ -118,8 +115,8 @@ - a floppy disk (works everywhere but it's painfully slow) - a RAM disk (fast, but allocates physical memory) - - a loopback device (the most elegant solution, but currently requires a - modified mount) + - a loopback device (the most elegant solution, but requires a recent + version of mount) We'll describe the RAM disk method: @@ -153,9 +150,9 @@ # dd if=/dev/ram bs=1k count=1440 of=/boot/initrd # freeramdisk /dev/ram -Finally, you have to boot the kernel and load initrd. Currently, -preliminary versions of LOADLIN 1.6 and LILO 18 support initrd (see -below for where to get them). With LOADLIN, you simply execute +Finally, you have to boot the kernel and load initrd. Current versions of +LOADLIN and LILO support initrd (see below for where to get them). With +LOADLIN, you simply execute LOADLIN <kernel> initrd=<disk_image> e.g. LOADLIN C:\LINUX\VMLINUZ initrd=C:\LINUX\INITRD @@ -238,9 +235,9 @@ 9) now the system is bootable and additional installation tasks can be performed -The key role of initrd here is to re-use the configuration data during -normal system operation without requiring the use of a bloated "generic" -kernel or re-compilation or re-linking of the kernel. +The key role of initrd here is to reuse the configuration data during +normal system operation without requiring the use of a bloated "generic" +kernel or recompilation or relinking of the kernel. A second scenario is for installations where Linux runs on systems with different hardware configurations in a single administrative domain. In @@ -251,15 +248,15 @@ read by it would have to be different. A third scenario are more convenient recovery disks, because information -like the location of the root FS partition doesn't have to be provided at +like the location of the root partition doesn't have to be provided at boot time, but the system loaded from initrd can use a user-friendly dialog and it can also perform some sanity checks (or even some form of auto-detection). -Last not least, CDrom distributors may use it for better installation from CD, -either using a LILO boot floppy and bootstrapping a bigger ramdisk via +Last not least, CDROM distributors may use it for better installation from +CD, either using a LILO boot floppy and bootstrapping a bigger ramdisk via initrd from CD, or using LOADLIN to directly load the ramdisk from CD -without need of floppies. +without need of floppies. Since initrd is a fairly generic mechanism, it is likely that additional uses will be found. @@ -268,18 +265,25 @@ Resources --------- -The bzImage+initrd patch (bzImage is an extension to load kernels directly -above 1 MB, which allows kernels sizes of up to approximately 2 MB) can be -found at -ftp://lrcftp.epfl.ch/pub/people/almesber/lilo/bzImage+initrd-1.3.71.patch.gz +Beginning with Linux 1.3.73, bzImage (an extension to load kernels +directly above 1 MB, which allows kernels up to approximately 2 MB in +size) and initrd are included in the mainstream kernel sources. For some +earlier kernels, patches may be found at: + +ftp://lrcftp.epfl.ch/pub/people/almesber/lilo/ + and -ftp://elserv.ffm.fgan.de/pub/linux/loadlin-1.6/bzImage+initrd-1.3.71.patch.gz -A preliminary version of LOADLIN 1.6 is available on -ftp://elserv.ffm.fgan.de/pub/linux/loadlin-1.6/loadlin-1.6-pre8-bin.tgz +ftp://elserv.ffm.fgan.de/pub/linux/loadlin-1.6/ + +You will also need at least LOADLIN 1.6 or LILO 18. Current versions are +available from: + +ftp://elserv.ffm.fgan.de/pub/linux/loadlin-1.6/ + +and -A preliminary version of LILO 18 is available on -ftp://lrcftp.epfl.ch/pub/people/almesber/lilo/lilo.18dev3.tar.gz +ftp://lrcftp.epfl.ch/pub/linux/local/lilo A very simple example for building an image for initrd, also including the program 'freeramdisk', can be found on
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