Hey I need to put the isolinux bootloader on an sd card but how do I properly do that?
Assuming that you can boot to the SD card, you might try using dd to write the ISO image to the SD card. Note that any image written this way may or may not have problems writing to the image, depending on how the ISO is configured. Also, you might destroy your Linux installation if you use incorrect parameters, so be careful.
This will allow you to look through your boot log for disks. Do this before and after putting the SD card into your working Linux machine. The device file /dev/sd? which is new to your list of visible drives will be your SD card. For example, let's say that it was assigned /dev/sdz.
This will take the contents of the ISO image and write it, bit for bit, to the SD card. The 'if' parameter is your input file, which should be your ISO image. The 'of' parameter is your output file, which should point to the SD card. This command may take some time, perhaps even several cups of coffee, so be patient. It's due to the low write speed of the memory inside the SD card and the speed of the USB bus.
Keep in mind that the /dev/sdz listed here is an example. If that were replace by the reference to an actual hard drive, that would be overwritten by the ISO image, causing irreparable damage to the Linux installation. Examine the results of the