======Creating bootable USB for ISO images======

// The steps below where tested to work on Devuan 1.0. //

Tools needed:
  * fdisk from util-linux (tested with 2.25.2)
  * mkfs.fat (tested with 3.0.27 (2014-11-12))
  * syslinux (tested with 6.03)

// Change /dev/sdd in the below example commands to the device name of the USB device. //

// Quick check: insert the USB device, execute the 'dmesg' command, and check the last lines for the /dev/sdX name (where X is the letter of the device. //

Start fdisk on the USB drive:
<code>
fdisk /dev/sdd
</code>

Enter the following commands in fdisk (partial instruction):
  - d to delete all partitions
  - n one primary partition, using all space
  - t and set it to type 'c' (w95 fat)
  - a to set it bootable
  - w to write changes

Format the partition as FAT32 (-F 32) and volume name USB (-n USB):
<code>
/sbin/mkfs.vfat -F 32 -n USB /dev/sdd1
</code>

"syslinux" the USB drive:
<code>
/usr/bin/syslinux /dev/sdd1
</code>

"cat" the MBR to disk:
<code>
cat /usr/lib/syslinux/mbr/mbr.bin > /dev/sdd
</code>

Mount the USB drive:
<code>
mount /dev/sdd1 /mnt
</code>

Copy memdisk, the .c32 files to the USB drive:
<code>
cp /usr/lib/syslinux/memdisk /mnt/
cp /usr/lib/syslinux/modules/bios/*.c32 /mnt/
</code>

Add the ISO file(s):
<code>
cp VMware-VMvisor-Installer-6.0.0.update02-3620759.x86_64.iso /mnt/
</code>

Create syslinux.cfg on the USB drive and fill it with:
<code>
DEFAULT menu.c32
LABEL VMware-ESXi-6.0.0.update02-3620759
KERNEL memdisk
APPEND iso
INITRD /VMware-VMvisor-Installer-6.0.0.update02-3620759.x86_64.iso
MENU LABEL VMware-ESXi-6.0.0.update02-3620759
</code>

Add more ISO's.
Copy the LABEL, KERNEL, APPEND, INITRD, and MENU LABEL to a new entry below the current one.
Change LABEL and MENU LABEL to name the menu entry.
Change INITRD to point to the new ISO file.


Sources:
  - [[https://pubs.vmware.com/vsphere-60/index.jsp?topic=%2Fcom.vmware.vsphere.upgrade.doc%2FGUID-33C3E7D5-20D0-4F84-B2E3-5CD33D32EAA8.html|VMware vSphere 6.0 Documentation Center - Format a USB Flash Drive to Boot the ESXi Installation or Upgrade]]
  - [[http://www.geeklee.co.uk/create-and-test-esxi55-usb/|geeklee's Notes - Create and test vSphere ESXi 5.5, 6 bootable USB installer]]