2.2 KiB
Executable File
Unbrick Ingenic T31 with SD Card
Ingenic T31 boot squence
If failed to boot from uboot on flash memory, T31 will then try to boot from SD card, no matter what bootsel pin is set. So if the uboot on flash chip is somehow broken, we can burn uboot to a SD card and boot from it. The uboot file should be specially compiled for SD card boot, you can't use the one for normal flash boot.
Compile uboot for SD card boot
mkdir /opt/t31
cd /opt/t31
git clone https://github.com/cgrrty/Ingenic-SDK-T31-1.1.1-20200508.git
cd Ingenic-SDK-T31-1.1.1-20200508/toolchain
unrar e toolchain.part1.rar
7z x mips-gcc472-glibc216-64bit-r2.3.3.7z
export PATH="$PATH:/opt/t31/Ingenic-SDK-T31-1.1.1-20200508/toolchain/mips-gcc472-glibc216-64bit/bin"
cd ../opensource/uboot/
make distclean
Now choose the final make command according to your T31 chip type
| SoC | Command |
|---|---|
| T31N | make isvp_t31_msc0 |
| T31L | make isvp_t31_msc0_lite |
| T31X | make isvp_t31_msc0_ddr128M |
| T31A | make isvp_t31a_msc0_ddr128M |
Now you will get the compiled uboot file u-boot-with-spl.bin
Burn uboot to SD card
Insert SD card to your PC, run fdisk -l to check, you should see the device like in my case Disk /dev/sdb: 29.72 GiB, 31914983424 bytes, 62333952 sectors. Pay attention to the physical sector size, in my case it's 512 bytes
dd if=./u-boot-with-spl.bin of=/dev/sdb seek=34
This will burn the uboot file to SD card at 34*512bytes=17KBytes offset from 0x0, where 512 is my SD card's block size. If yours is 1024, change seek=34 to seek=17, to make the offset to be 17KBytes
Boot from SD card
If the original uboot on flash chip is broken or empty, it will choose to boot from SD card automatically, but if you just want to sideload your own uboot when there's working uboot on flash chip and camera PCB board's bootsel pin is set to 1, it will still boot from uboot on flash chip. To force booting from SD card, you can short circut pin 5 and 6 of the SOIC8 flash chip when powering up camera to block reading of the flash memory, details here.