I don't use unetbootin or those custom scripts. I create a Live USB manually. The steps are more involved, but it works as I've tested it.
I will use tinycore_3.2 in this example.
Plug in your USB stick.
Run this code to see all logical block devices.
dmesg | egrep hd.\|sd. | grep -i 'logical'
sd 0:0:0:0: [sda] 180941040 512-byte logical blocks: (92.6 GB/86.2 GiB)
sd 0:0:1:0: [sdb] 29886400 512-byte logical blocks: (15.3 GB/14.2 GiB)
sd 4:0:0:0: [sdc] 7837696 512-byte logical blocks: (4.01 GB/3.73 GiB)
Above is the output from my system. Yours will vary. Anyway, you can see sdc
is the USB stick by the size (4.01 GB/3.73 GiB).
The next steps must be done as root
Using fdisk or cfdisk, create a vfat or linux partiton on the USB stick and set the boot flag on in that partition.
Next, format the partition with either mkfs.vfat or mkfs.ext3 depending on partition type you created above.
Next, mount the iso image and the USB drive. I will use /mnt/iso and /mnt/usb in this example.
mount -o loop tinycore_3.2.iso /mnt/iso/
mount /dev/sdc1 /mnt/usb/
Next, copy all files and directories from /mnt/iso to /mnt/usb.
rsync -r /mnt/iso/ /mnt/usb/
grub-install --no-floppy --root-directory=/mnt/usb/ /dev/sdc
IMPORTANT: Make sure you specific the right drive of your USB stick!
Create or edit /mnt/usb/boot/grub/menu.lst
Add these lines
Some of you may be asking where is the hdx,x part. Well, it is not needed at least in the case. I did add the hdx,x part before, but it didn't work. It worked only when I enter it as above.
Save the file.
That's it. Whew...
Reboot the system and change the BIOS to boot off the USB drive first.
If your BIOS does not support booting off USB drives, use this bootloader
If you've done everything correctly, you will see tinycore in the grub boot menu.
Like I said, I done this a few days ago and it worked like a charm and I tested it again with crux linux by modifying the menu.lst and it booted fine too.
At first, it looks like alot of work, but it's really not. Here is a recap.
Determine which drive your USB drive is using.
Create the partition with fdisk or cfdisk and toggle boot on.
Format the partition
Mount the iso image and the USB drive
Copy all files and directories from the iso folder to the usb folder
install grub to the root directory of the USB drive and create or edit the menu.lst.
Save file & Reboot