Hack-A-N900/Usb Recovery Mode

aus Metalab Wiki, dem offenen Zentrum für meta-disziplinäre Magier und technisch-kreative Enthusiasten.
Version vom 28. September 2012, 08:52 Uhr von Hmw (Diskussion | Beiträge) (→‎Enable R&D mode and disable watchdogs: Link to flasher web site added)
(Unterschied) ← Nächstältere Version | Aktuelle Version (Unterschied) | Nächstjüngere Version → (Unterschied)
Zur Navigation springenZur Suche springen

I bricked my maemo setup several times. Often the underlying problem would have been trivial to fix, if i had a way to access the rootfs. Patching bootmenu enables us to boot a minimal system with just usb network and sshd enabled. that's still not optimal because this solution relies on rootfs being accessible. why? - 1 2 - in short, during boot process no seperate initrd is utilized - in fact the rootfs is misused for it -.- . the bootmenu script circumvents that by redirecting the pivot_root call issued by /sbin/preinit, which is a pretty dirty - yet effective hack. hmmm... just an idea, but why not use the rootfs for initrd purposes only?... sshd will be using settings from the rootfs.


Prerequisites

Install bootmenu

Login via ssh to your n900 and:

# Get the bootmenu package:
wget http://www.daimi.au.dk/~cvm/bootmenu_1.6_armel.deb

# Install bootmenu package
dpkg -i bootmenu_1.6_armel.deb

# Install bootmenu script
install_bootmenu

Patch bootmenu.sh to fix key bindings and enable usb recovery mode

cd /
wget http://metalab.at/wiki/images/4/40/Bootmenu_n900usbrecov.patch
patch -p0 < Bootmenu_n900usbrecov.patch

If you like you can edit /bootmenu.conf and adjust the ip address the usb interface will start with in recovery mode:

# IP address for USB networking
USB_IP=192.168.2.15

Enable R&D mode and disable watchdogs

Enable flasher mode and execute following on your pc:

./flasher-3.5 --set-rd-flags=no-omap-wd
./flasher-3.5 --set-rd-flags=no-ext-wd
./flasher-3.5 --enable-rd-mode

Boot into recovery mode

Reboot the device with the keyboard slide out(!). When the boot menu appears you can either select a boot entry or press "CTRL" to boot usb recovery mode.