Ok thanks uboot because of you fast answer
I change some of my sony prs-t1 system file and when I try to restart it ,it never turn on hang on opening book.so I decide to use your best file.
but I do not underestant just this line:
To apply any of the rescue packages you need to unzip the file to the root of a micro sd card
Ok .I download it . after Unzip it ,There is Update.img file in it that it size is 300 mg ,Ok.
should I transfer update.im to my ram or I had to extract Image file.