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how to boot from sd in card reader
i installed ubuntu 8.04 on a sd card with boot flag on first partition, grub correctly installed and everything working fine. To install it i used a usb card reader on a desktop.
I put that sd card on the inspiron 1420n that arrived recently and doesn't detect the drive. So i can't boot on it. I have the same problem on a new vostro.
On the bios I have:
usb emulation on
Bios version A08
any ideas?
thanks
dgkpcon
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June 19th, 2008 23:00
AlxMAX
168 Posts
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June 20th, 2008 14:00
It seems the link points to pieces of documentation about booting PDAs or other similar devices. Was this your intention?
framallo
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June 20th, 2008 15:00
didn't understand it either, also doesn't use grub or debian based distros :S
maybe i missed something?
The sd card works fine from a usb card reader. Boots ok,load ubuntu, detects bluethoot, wifi, sound,usb, etc.
ok, so far what i've got is this:
* The bios doesn't recognise car reader as a booting device (as said on the user manual) snif.
* aprox startup time to desktop:
* Dell's preinstalled ubuntu 7.10 1m
* Ubuntu 8.04 from sd with usb card reader 1m 40s
What i did:
I copied all files from sd to the partition number 4 in HD.
updated grub devices.map:
sudo grub-install --recheck /dev/sda
created a grub menu entry in /boot/grub/menu.lst to boot ubuntu 8.04.
root (hd0,3)
kernel /boot/vmlinuz-2.6.24-19-generic root=/dev/sda4 ro quiet splash
initrd /boot/initrd.img-2.6.25-19-generic
quiet
The problems i found are:
* brightness have only 3 levels against 4 or more on 7.10
* Using powertop, power usage is 23.7W and 51 wakeups per second on 8.04 against 18-19W and like 600 wakeups per second on 7.1
* Doesn't recognise card reader
I don't know if it's a version problem or config problem yet. Remember the 7.10 is preinstalled while 8.04 is a fresh install with dell's ppa updated:
http://linux.dell.com/wiki/index.php/Ubuntu_8.04/Issues/Update_Dell_PPA_Entry
Also tried root=/dev/mmcblk0p1 wich is the card reader, instead of /dev/sda4 but couldn't get it work. I'm no grub expert. What it seems to do is to boot from partition 3 from HD, then try to find a second stage to continue start up. At this point /dev is populated. The problem now is that ubuntu 8.04 is not detecting the card reader. Maybe a kernel module is missing or something.
Also what could be done is to have a unionfs or aufs with hd and sd card to use it as a cache of all OS and some files. The idea is to stop the HD and extend battery life.
https://help.ubuntu.com/community/aufsRootFileSystemOnUsbFlash?highlight=(aufs)
http://aufs.sourceforge.net/