similar to: Reason for gen_init_cpio instead of just cpio?

Hi, Here's a try at writing an initramfs HOWTO. This is basically a write-up of a number of interesting emails I collected over time. It could probably use an editor, more fact-checking and a bunch of other good things, but it should be better than nothing ;-) Daniel -------------- next part -------------- INITRAMFS HOWTO 0) What are klibc and initramfs? Initramfs is a ramfs into which

(Apologies to klibc@zytor.com for the re-send) This patch makes gen_init_cpio generate the initramfs_data.cpio from a file which contains a list of entries: file, dir, nod. I swapped the order of filename/location for the file arguments so that it would be more uniform with the dir and nod tyes. [thayne@torch linux-2.6.8]$ usr/gen_init_cpio --help ERROR: unable to open '--help': No such

Last patch for now. This gets gen_init_cpio into a state where it can pick up a "kinit" binary from usr and stuff it into the cpio archive as /sbin/init. This is obviously a crock, but it suffices for testing until something sane is done about integrating klibc into the kernel tree. The patch also adds a bit of instrumentation to initramfs.c, to try to help flush out bug 740.

Generate dependencies almost like done by fixdep in the kernel. This teaches make to rebuild cpio image when content has changed. Also restructured usr/Kbuild a little so we better utilise parallel makes (dash, gzip, utils and kinit are now build in parallel). Signed-off-by: Sam Ravnborg <sam@ravnborg.org> --- patch is on top of hpa's linux tree, so path differ if applied to the klibc

Hi I am looking at inserting functions in the early user space and want to use initramfs for this. I understand this can be achieved using 'initrd' or by making changes in the 'usr/gen_init_cpio.c' file. Can someone kindly give me pointers as to how to go about this. I am looking at the 2.6.x kernel. Thanks Rachita.

Unlink files, symlinks, FIFOs, devices etc. (except directories) before writing them when extracting CPIOs. This stops weird behaviour like: 1) writing through symlinks created in earlier CPIOs. eg foo->bar in the first CPIO. Having foo as a non-link in a subsequent CPIO, results in bar being written and foo remaining as a symlink. 2) if the first version of file foo is larger

The patch makes gen_init_cpio generate the initramfs_data.cpio from a file which contains a list of entries: file, dir, nod. I swapped the order of filename/location for the file arguments so that it would be more uniform with the dir and nod tyes. [thayne@torch linux-2.6.8]$ usr/gen_init_cpio --help ERROR: unable to open '--help': No such file or directory Usage:

This fix has been implemented in preparation for the upcoming klibc merge in -mm. But as it fixes a real (but rare I hope) bug in vanilla kernel it will be added to my pending 2.6.17 kbuild queue. I've done quite some changes to the gen_initramfs script and being shell programming newbie review by more experienced shell hackers would be appreciated. I did a git mv

I was wondering if it would be possible to add a cpio (extraction) implementation to klibc. Maybe this can be done in a way that the code could bet shared between klibc and init/initramfs.c in the kernel. Background of what I'm trying to do: I want to load an initramfs from flash on a number of different devices. The devices are quite similar but the partition in flash where the initramfs

hpa notified me in private mail that we have an issue that when building initramfs - if the content changes (say kinit) then the initramfs will not be rebuild. The solution I have come up with is to let make check all the files included in the initramfs and rebuild it if any files are newer than the initramfs and also rebuild if arguments changes (root_uid). In same process the usr/Kbuild file

Hello, There seems to be problem in the cpio unpack in the kernel in initramfs. I have an empty "/sys" directory in my cpio archive, but it never shows up in my extracted initramfs. I've confirmed that extracting the archive again with cpio results in a correct tree, but it doesn't appear on boot when extracted by the kernel. Any ideas? I poked a bit, but I haven't

At present the configuration items for initramfs is located in: Device drivers | Block Drivers | xxx This is maybe not the most natural place to have it. So with the following patch it is moved below "General setup", and relevant config items are collected in a file with a new home in usr/. The original reason why I looked into this is the upcoming merge of klibc and I missed a good

Fix usr/Kbuild so it utilise the new gen_initramfs.sh script which will rebuild initramfs when the content has changed. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> --- usr/Kbuild | 74 +++++++++++++++++++---------------------------------------------- 1 file changed, 22 insertions(+), 52 deletions(-) This patch shall not be applied until my kbuild.git tree is merged upstream. Or it

Harcoding default content of initramfs in the gen_initramfs_list.sh script seems ackward. Move it to a file named: usr/initramfs.default This also fixes a small bug when no arguments was passed to CONFIG_INITRAMFS_SOURCE (-d was passed twice to the script) Idea and bug report from: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Sam Ravnborg <sam@ravnborg.org> ---

gen_initramfs_list.sh failed to generate a dependency list when it was supplied the -d option. Restructured gen_initramfs_list.sh to support dependency info with -d. This also fixes a bug where we did not properly process when more than one dir was specified. Finally update dependency info for the -d case (list_default_initramfs) In usr/Kbuild remove "" around CONFIG_RAMFS_SOURCE so the

--32u276st3Jlj2kUU Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi all (two) klibc hackers! 8) Here's the stuff I've been using to build an initramfs image and run it on one of my machines. Unfortunately, the "init" script contains hard coded information about where to find the root, etc, but it should give people a working base to start from. It

Harcoding default content of initramfs in the gen_initramfs_list.sh script seems ackward. Move it to a file named: usr/initramfs.default This also fixes a small bug when no arguments was passed to CONFIG_INITRAMFS_SOURCE (-d was passed twice to the script) Idea and bug report from: "H. Peter Anvin" <hpa at zytor.com> Signed-off-by: Sam Ravnborg <sam at ravnborg.org>

The following patch unlinks (deletes) files, symlinks, FIFOs, devices etc before writing them when extracting CPIOs. It doesn't delete directories. This stops weird behaviour like: 1) writing through symlinks created in earlier CPIOs. eg foo->bar in the first CPIO. Having foo as a non link in a subsequent CPIO, results in bar being written and foo remaining as a symlink. 2)

Hi Bryan and other klibc people. I have taken a stamp on the Makefiles for klibc, this is what I came up with. 1) No longer recompile on every invocation 2) Correct checking on dependencies 3) Simpler makefile syntax (almost all over the place) I compile-time tested it only. Two open issues: a) Do we realy use .a files for initramfs. I renemed that to the executable. b) I renamed

> -----Original Messages----- > From: "Steven Tardy" <sjt5atra at gmail.com> > Sent Time: 2018-02-26 10:48:48 (Monday) > To: "CentOS mailing list" <centos at centos.org> > Cc: > Subject: Re: [CentOS] How to update modules in iniramfs fastly > > On Sun, Feb 25, 2018 at 8:29 PM wuzhouhui <wuzhouhui14 at mails.ucas.ac.cn> > wrote: