@sowbhagya lakshmi reset the board or else remove the power and plug in.

@sowbhagya lakshmi cp uboot.bin,zImage,at91-sama5d27_som1_ek.dtb into boot partition. extract (sudo tar -xvf rootfs.tgz )core-image-minimal-sama5d27-som1-ek-sd-20191203074105.rootfs.tar.gz in rootfs partition after that use sync command and plug in the sdcard and boot the board

make two partictions 1.boot 2.rootfs copy all images in boot partition except rootfs & copy the rootfs in rootfs partition . follow the below steps step1: get the prebuilt images from Ashraful and directly copy into boot partition by using cp command (cp boot.bin /media/gopal/boot) Note: boot partition should be bootable. step2: for flashing rootfs follow below command sudo tar -xvf rootfs-name -C /media/gopal/rootfs

if you wish to do add any more packages have to boot board with sdcard since flash is limited memory space .

let me know ur booting boot with sdcard or nor flash..there is possibility if you boot board with sdcard .

you could not install pymodbus since root filesystem is readonly....

Is it putty working fine let me know and board is booting r not.

You can use SD-Card and make two partitions like "boot & rootfs " copy the images uboot.bin zimage, x.dtb file into boot partition and extract root file system in rootfs partition and insert SD-Card into A5d2x and power-on