Bootability with multiple logical unit numbers

A flash memory device including a processor and a non-transitory machine-readable medium having stored thereon instructions executable on said processor to perform a method including:

• booting a computer system from a first logical disk, said first logical disk being specified by a first logical unit number, wherein said flash memory device reports a single logical unit number to said computer system and said computer system is initially configured to recognize only a single logical disk such that only said single logical unit number is visible to said computer system, said first logical disk including first software instructions for a preboot environment;
• configuring said processor on said flash memory device to replace said first logical unit number with a second logical unit number, said processor exchanging values for said first logical unit number and said second logical unit number as directed by the instructions in said flash memory device;
• rebooting said computer system from said second logical unit number, wherein only said second logical unit number is visible and said computer system reboots from said second logical disk indicated by said second logical unit number;
• and by second software instructions on a second logical disk specified by said second logical unit number, exposing one or more additional logical unit numbers;
• and
• executing a portable operating environment in said second software instructions, said portable operating environment including said one or more additional logical unit numbers indicating one or more additional logical disks available on the flash memory device;
• wherein said computer system is only able to initially boot from said flash memory device if said flash memory device reports only said single logical unit number to said computer system and said portable operating environment incorporates an interpolated device driver that configures said processor to expose said additional logical unit numbers before other device drivers are loaded.

A method, including:

• booting a computer system from a first logical disk on a USB device having a processor and multiple logical disks available, said first logical disk including instructions:
• to configure said computer system to remove access to said first logical disk, to configure said processor to replace said first logical disk to add access to a second logical disk of said multiple logical disks on said USB device, said processor exchanging logical unit values for said first logical disk and said second logical disk as directed by instructions in said USB device, and to configure said computer system to reboot from said second logical disk;
• wherein said computer system is initially configured to recognize only a single logical disk and is only able to initially boot from said USB device if said USB device reports only a single logical unit number indicating said single logical disk to said computer system and only said single logical unit number is visible to said computer system;
• rebooting said computer system from said second logical disk wherein only said second logical disk is visible, said second logical disk including instructions for an interpolated device driver to configure said processor to expose one or more additional logical disks of the multiple logical disks available on the USB device before starting a portable operating environment embodied on the USB device;
• and
• starting said portable operating environment embodied on said USB device, wherein a user of the portable operating environment maintains settings for personalized use on the computer system.