I'm Using SAMA5D28 custom board. Using sam-ba_3.2.0 for programming.
We also have signed NDA with microchip and have got the "Secure Boot Strategies" documentation and Secure sam-ba-loader and secure-sam-ba-cipher. And also got the secure sam-ba "licence" for my PC.
By mistake wrong fuse values are set and I'm not able to revert them back.
is there any way to RESET the "Boot configuration word" register FUSE bits to default? OR these "Boot configuration word" register FUSE bits only OTP bits?
I want to enable BSCR, SPI0_IOSET1, NANDFLASH(IOSET2), and SDMMC1..
Here are the fuse readings:
ganesh@ganesh-14# sudo sam-ba -p usb -d sama5d2 -a bootconfig -c readcfg:fuse
Opening serial port 'ttyACM0'
Connection opened.
Executing command 'readcfg:fuse'
FUSE=0x00440fff / QSPI0_DISABLED,QSPI1_DISABLED,SPI0_DISABLED,SPI1_DISABLED,NFC_DISABLED,SDMMC0_DISABLED,SDMMC1_DISABLED,UART1_IOSET1,JTAG_IOSET1,EXT_MEM_BOOT,DISABLE_BSCR
Connection closed.
ganesh@ganesh-14#
I tried the following command to enable the appropriate bits in the fuses:
ganesh@ganesh-14# sam-ba -p usb -d sama5d2 -a bootconfig -c writecfg:fuse:ext_mem_boot,sdmmc1,sdmmc0_disabled,nfc_ioset2,spi1_disabled,spi0_ioset1,qspi1_disabled,qspi0_disabled
Opening serial port 'ttyACM0'
Connection opened.
Executing command 'writecfg:fuse:ext_mem_boot,sdmmc1,sdmmc0_disabled,nfc_disabled,spi1_disabled,spi0_ioset1,qspi1_disabled,qspi0_disabled'
Setting FUSE to 0x000407cf (QSPI0_DISABLED,QSPI1_DISABLED,SPI0_IOSET1,SPI1_DISABLED,NFC_IOSET2,SDMMC0_DISABLED,SDMMC1,UART1_IOSET1,JTAG_IOSET1,EXT_MEM_BOOT)
Connection closed.
ganesh@ganesh-14# sam-ba -p usb -d sama5d2 -a bootconfig -c readcfg:fuse
Opening serial port 'ttyACM0'
Connection opened.
Executing command 'readcfg:fuse'
FUSE=0x00440fff / QSPI0_DISABLED,QSPI1_DISABLED,SPI0_DISABLED,SPI1_DISABLED,NFC_DISABLED,SDMMC0_DISABLED,SDMMC1_DISABLED,UART1_IOSET1,JTAG_IOSET1,EXT_MEM_BOOT,DISABLE_BSCR
Connection closed.
Again its the same fuse values..


Please help me in regarding this issue..
Thanks,
-Ganesh