JFYI
I was able to run Puppy Linux slacko64-7.0 from a folder on the root of U-BOOT partition.
Procedure:
Create Slacko64-7.0 folder on the root of U-BOOT partition.
Download the ISO and extract to that folder, as a bare minimum only following files are required:
fdrv_slacko64_7.0.sfs, initrd.gz, puppy_slacko64_7.0.sfs, vmlinuz and zdrv_slacko64_7.0.sfs (332 MB in total).
This are the menu entries I used:
For a folder (Slacko64-7.0) on the root of U-BOOT (FAT-32) partition on USB device
Default KBD is en-US but can be changed on first boot; pkeys=es is a sample to set my Spanish KBD, delete it if unneeded.
MBR grub4dos
iftitle [if exist (hd0,0)/Slacko64-7.0/puppy_slacko64_7.0.sfs] Puppy Linux Slacko64-7.0 - (hd0,0)/Slacko64-7.0
kernel /Slacko64-7.0/vmlinuz pmedia=usbflash pdrv=U-BOOT psubdir=/Slacko64-7.0 pkeys=es pfix=fsck,fsckp
initrd /Slacko64-7.0/initrd.gz
Grub 2
menuentry "Puppy slacko64 7.0" {
echo "Loading vmlinuz"
linux /Slacko64-7.0/vmlinuz pmedia=usbflash pdrv=U-BOOT psubdir=/Slacko64-7.0 pkeys=es pfix=fsck,fsckp
echo "Loading initrd.gz"
initrd /Slacko64-7.0/initrd.gz
}
On first boot you are able to edit your settings, connect to your LAN, etc. when you turn off the OS you have the option to create a persistence file, if using default settings it will be slacko64save.4fs file, located into Slacko64-7.0 folder.
NOTE: Every time you close the OS you are allow to save changes or not as you prefer.
alacran