Imx6q is allowing me to fuse MAC address twice

[Rojesh]

Hi,

I'm using the below script to fuse my imx6q boards MAC address. It's allowing me to fuse the MAC address twice. After the second time it's not allowing me to fuse

#FB: ucmd setenv fastboot_dev mmc
#FB: ucmd setenv mmcdev ${emmc_dev}
FB: ucmd fuse sense 4 2
FB: ucmd fuse sense 4 3
FB: ucmd fuse sense 0 6
FB: ucmd fuse prog 4 2 4AF00005
FB: ucmd fuse prog 4 3 0023
FB: ucmd fuse prog 0 6 0x100000
FB: ucmd fuse sense 4 2
FB: ucmd fuse sense 4 3

# Download Kernel to be executed from RAM
FB: ucmd setenv fastboot_buffer ${loadaddr}
FB: download -f zImage

# Download DTB
FB: ucmd setenv fastboot_buffer ${fdt_addr}
FB: download -f imx6q-consoleui.dtb

Can you please guide me on where it's going wrong? 

[Harvey021]

Hi @Rojesh 

A fuse corresponds to a single non-volatile memory bit that can be programmed(i.e. blown, set to 1) only once. The programming operation is irreversible. A fuse that has not been programmed reads 0. 

Best regards

Harvey

[Rojesh]

Hi Harvey,

I have tried fusing it, but the fuse programming isn't working on the first attempt but succeeds on the second. I'm not able to understand the reason. 

Can you please share the procedure for how to fuse the MAC ID on the imx6 devices, if you have any reference documents please share them with me.

The code which I'm using to fuse MAC ID  is below

" echo "adding MAC address to script"
echo $var

sed -i "15i FB: ucmd fuse sense 4 2" artifacts/hds_gui_emmc_flash.uuu
sed -i "16i FB: ucmd fuse sense 4 3" artifacts/hds_gui_emmc_flash.uuu
sed -i "17i FB: ucmd fuse sense 0 6" artifacts/hds_gui_emmc_flash.uuu
sed -i "18i FB: ucmd fuse prog 4 2 $var1" artifacts/hds_gui_emmc_flash.uuu # Fuse MAC Address 32 bit
sed -i "19i FB: ucmd fuse prog 4 3 $var2" artifacts/hds_gui_emmc_flash.uuu # Fuse MAC Address 16 bit
sed -i "22i FB: ucmd fuse prog 0 6 0x100000" artifacts/hds_gui_emmc_flash.uuu # JTAG Disabled
sed -i "23i FB: ucmd fuse sense 4 2" artifacts/hds_gui_emmc_flash.uuu
sed -i "24i FB: ucmd fuse sense 4 3" artifacts/hds_gui_emmc_flash.uuu
"

Thank you,

Rojesh M