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= Alternate Boot Device
Some Gateworks family products have an 'Alternate boot device' that can be used for alternate firmware images, such as a flash recovery image:
 * Newport - eMMC vs microSD

== Auto Switch Boot Device
The [wiki:gsc Gateworks System Controller] implements an 'Auto Switch Boot Device' feature that can be useful as a firmware recovery mechanism. GSC register R1.6 (SWITCH_BOOT_ENABLE) enables this mode. When this is set and the board powers on it will initiate a countdown timer cleared by the boot firmware that expires in 30 seconds. Therefore if the boot firmware is missing/corrupt the board will power cycle and boot off the alternate device.

To enable from Linux:
{{{#!bash
i2cset -f -y 0 0x20 1 0x40      ;# enable R1.6 (SWITCH_BOOT_ENABLE)
}}}

To enable from u-boot
{{{#!bash
i2c dev 0 && i2c mw 0x20 1 0x40 1     ;# enable R1.6 (SWITCH_BOOT_ENABLE)
}}}