09-07-2018, 05:27 AM
OK,
Then, please obtain OS-Image from url below and write it on SD-Card and try it.
https://github.com/ayufan-rock64/linux-build/releases
OS-Image can be small in size, for example the following one
"bionic-minimal-rock64-0.7.9-1067-arm64.img.xz"
If you have eMMC, insert a clamp jumper and disable it.
You should be able to boot from SD-Card with Pin 21 clamped to GND.
Pin 21 does not need to release clamps on the way.
If you can boot it, you can erase the SPI by another means.
If it can not be started with this method,
Please check the connection of pin 21 & pin 20 again.
---
If there is no problem with connection but startup is impossible,
It may be in a serious condition.
If unfortunately the situation is above, I do not have any more useful information for you
Then, please obtain OS-Image from url below and write it on SD-Card and try it.
https://github.com/ayufan-rock64/linux-build/releases
OS-Image can be small in size, for example the following one
"bionic-minimal-rock64-0.7.9-1067-arm64.img.xz"
If you have eMMC, insert a clamp jumper and disable it.
You should be able to boot from SD-Card with Pin 21 clamped to GND.
Pin 21 does not need to release clamps on the way.
If you can boot it, you can erase the SPI by another means.
If it can not be started with this method,
Please check the connection of pin 21 & pin 20 again.
---
If there is no problem with connection but startup is impossible,
It may be in a serious condition.
If unfortunately the situation is above, I do not have any more useful information for you