Hi,
I need to boot Linux form USB pen drive

wrt : http://www.freescale.com/files/32bit...ote/AN3217.pdf

for booting linux from u-boot from USB flash I need
1. USB Host controller support in u-boot support to detect ped drive
2. initial small & simple RAM disk.
3. USB stick with actual Images kernel & rootfs.
4. First kernel will use initial RAM disk & then actual rootfs from USB.

My question is
1. How will initial RAM disk (initial rootfs) come into picture :
As at the beginning pen drive will not be detected (without any fs).
And there will not be any on board NAND flash.
OR
Is it the case that u-boot understands VFAT formatted pen drive

Niraj Kulkarni.

Hi -

I assume you're probably not already familiar with Linux (or you probably wouldn't be asking these questions).

STRONG SUGGESTION:
Make a bootable USB stick, and try it out. Simply experimenting - experimenting with *ANY*thing - will help you ENORMOUSLY.

Maybe you can easily make a bootable USB of the Linux you're referring to. If so - great. Please "just do it", and do it as soon as possible.

Otherwise, there are other Linux distros which you *should* easily be able to create a bootable USB stick with. Here are are four different, easy-to-use links for one such option, "Puppy Linux":

http://www.pendrivelinux.com/puppy-linux-on-usb/

http://www.puppylinux.com/flash-puppy.htm

http://www.pcmech.com/article/puppy-...-stick-how-to/

http://maketecheasier.com/how-to-ins...ive/2008/06/27

'Hope that helps .. PSM

You can make a USB bootable linux by installing a bootloader in the USB drive and the setting the configuration files to load proper kernel and initrd images, and parameters.

You can follow this guide, this might help you: http://phoxis.wordpress.com/2009/09/...boot_cddvdusb/

In short install syslinux in USB as

cp /path_to/vesamenu.c32 /path/to/syslinux/dir/of/usb
cp /path_to/isolinux.bin /path/to/syslinux/dir/of/usb/syslinux.bin
syslinux -sd /path/to/syslinux/dir/of/usb /dev/sdXy

where /dev/sdXy is the partition where you are keeping the OS. Run syslinux as superuser

and make a config file syslinux.cfg

LABEL osname_label_for_text
MENU LABEL OS Label Shown in Manu
KERNEL /path/to/kernel/in/usb/kernel.bin kernelparameters
APPEND initrd=/path/to/initrd/in/usb/initrd.img

check the OS documentation for details with kernel parameters, and you need to check syslinux info page.
Or you can also use GRUB.

Thanks paulsm4 , Phoxis & all viewers
I think I should have mentioned that I am working on ARM processor with u-boot on it.
And my question was with respect to my embedded board and not Linux machine.
I am sure this experimentation will work.
Thks again.
Niraj