Using an initrd

[pezz]

Hi there,

I was wondering if anyone had some information / documentation on what's needed, or whether it's even possible, to get an initrd image to load in order to do some pre-boot stuff?

I can create an image easy enough, but not sure if the normal images generated by mkinitcpio would even work, and where or how you specify to load it like you do in grub.cfg for a regular Linux system.

Love the distro though, runs great on my Pi.

Cheers.

- Pezz

[pezz]

Just read some kernel documentation, there's actually an initrd parameter, so I just added it to cmdline.txt:

$this->bbcode_second_pass_code('', '
smsc95xx.turbo_mode=N dwc_otg.lpm_enable=0 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 console=tty1 loglevel=2 initrd=/initramfs-linux.img root=/dev/mmcblk0p2 elevator=noop rootfstype=ext4 rootwait
')

[pezz]

Well, I've had a real go at this (I think), but I can't get it working.

Best I've done is making my own initrd.img, and using some guy's start.elf to get it to load:

http://www.raspberrypi.org/phpBB3/viewt ... 63&t=10532

Using this in config.txt:

$this->bbcode_second_pass_code('', '
disable_commandline_tags
ramfsfile=initrd.img
ramfsaddr=0x00a00000
initramfs initrd.img 0x00a00000
')

I get output at least.

Is there any way to get an initramfs working, just by using mkinitcpio, so I can use the hooks available in regular Arch Linux?

I'd love a clear explanation on how this all works, compared to a normal system ARM / RPi is just black magic.

[pezz]

Also, cmdline.txt has:

$this->bbcode_second_pass_code('', '
initrd=0xa00000,0x2b020c
')

Second arg is the length of my img.

[pezz]

In case anyone's interested - I got this working. Now booting off an encrypted root with passphrase entry over SSH with the dropbear_initrd_encrypt hook.

Very happy, and I'll provide more details if anyone is interested (do an Arch Wiki page?).

Also, can I just say, as I needed to compile a kernel and enable CONFIG_BLK_DEV_INITRD=y -- the availability of the PKGBUILD etc on Github, and the x-tools for distcc'ing to another box, helped immensely. Excellent instructions.

Wonderful work guys, bloody brilliant.

[pinoverclock]

Hi, this is my very fisrt post at this forum, I've got my Raspberry Pi few days ago and i love having my favorite dristo running on it, Must say the dd'ing process is quite straightforward.
I tried to set lvm support at boot time so i included lm_mod module and lvm2 hook at /etc/mkinitcpio.conf file and tried to generate a kernel image with mkinitcpio the archlinux way, no luck so far... so i think i must be done in a completely different way.

Any hints?

Thank you very much

[gfvos]

pezz, I hope you're still reading the forum.

For the love of god, PLEASE share the steps of how you did that, I've been ripping my hair out over this. Setting up encrypted root and dropbear_initrd_encrypt on several of my x64/x86 PCs wasn't a problem with arch's installer and wiki instructions, but I never managed to do the same on the raspberry pi.

[pezz]

A while ago, a kernel update completely broke the setup and I haven't had a chance to get back to it and set it up again.

I'll try and make some time this weekend to re-do it and post the results. I still have my config and kernel command line settings backed up, so hopefully it shouldn't take me too long to do it.

Sorry for not getting back to you.

[moonman]

http://www.daves-collective.co.uk/raspi/notes.shtml

[pezz]

$this->bbcode_second_pass_quote('moonman', 'h')ttp://www.daves-collective.co.uk/raspi/notes.shtml