Version 7 (modified by 7 weeks ago) ( diff ) | ,
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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 (primary) vs microSD (alternate)
Auto Switch Boot Device
The 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:
i2cset -f -y 0 0x20 1 0x40 ;# enable R1.6 (SWITCH_BOOT_ENABLE)
To enable from u-boot
i2c dev 0 && i2c mw 0x20 1 0x40 1 ;# enable R1.6 (SWITCH_BOOT_ENABLE)
Current Boot Device
The current boot device is held in GSC register R21 (0x15) with a value of 0 being primary and a value of 1 being alternate. This value will be toggled by the 'Auto Switch Boot' feature above but can also be manually set:
From Linux:
- Alternate
i2cset -f -y 0 0x20 0x15 1 # set boot device to 1 (alternate)
- Primary
i2cset -f -y 0 0x20 0x15 0 # set boot device to 0 (primary)
U-Boot:
- Alternate:
i2c dev 0 && i2c mw 0x20 0x15 1 # set boot device to 1 (alternate)
- Primary:
i2c dev 0 && i2c mw 0x20 0x15 0 # set boot device to 0 (primary)