success after problems

Forum: USB booting
Topic: success after problems
started by: dewman

Posted by dewman on June 24 2005,18:12

I am writing this from DSL booted on a Dell D600 laptop, from a Lexar 256 jumpdrive. I've been lurking for quite some time. I didn't want to use the install scripts and struggled with this for a long while. So, let me share.

Use at your own risk. dd can be very bad if used improperly

I started with a lexar 256 and the first thing I did was mess up the geometry.

Once I did that, nothing would work right for me. I tried multiple different posted methods of getting DSL to boot off usb. So, I buckled down and RTFM.

I found out that syslinux doesn't write it's boot code to the master boot record. It writes it to the boot sector of the bootable partition, which is correct. I had screwed up my master boot record, which isn't necessarily related to syslinux.

So, here it he process that eventually worked for me.

I used dd to zero out the whole pen drive.
# dd if=/dev/zero of=dev/sda bs=512

Then I partitioned it using the geometry that a friend send me of his lexar, taking care to use 32 sectors/track.

# sfdisk -f -C984 -H16 -S32 /dev/sda

answers to sfdisk
0,200,6 * - this makes FAT partition with bootable to put dsl into
then just hit enter to get
200,983,83 - this makes Linux partition to write to later. I have yet to get that mounted

Here is what was KEY for me. Use dd to write the syslinux mbr file to the first 446 bytes of the mbr on the usb drive. The mbr.bin file comes with syslinux.

# dd if=/home/user/mbr.bin of=/dev/sda count=1 bs=446

This writes in the master boot record code, but leaves the partition information alone. The partition info is in the space between 446 and 512 bytes.

Then I put in laptop on XP and right clicked on drive to format. XP only sees the first partition and formats just that. The HP tool formats the whole thing, so that wouldn't work for me.

Then I use WinImage to write the usb boot disk image (auto resized it), and then ISO program to extract the files from a current dsl iso image to put knoppix on usb drive.

booting worked, but dls wouldn't run correctly until I gave the toram boot directive.

Anyway, I'm very happy to be running dsl from my Lexar pen drive and I'm now going to get my linux partition mounted to save files.

I'm sure there is more than one way to do this, and maybe grub or lilo might work better. I plan to learn more, but I learned a ton about CMOS, partitions and the boot process getting through this.

Thanks to all who posted information on usb booting. I learned from you and other boot tutorials. I hope this information helps someone with bad geometry.

Regards,
dewman