How tot read registers in terminal
 

Hi, there
I want to known if there is a way to read registers through hexdump&/dev/mem,
Thank you very much.

You mean CPU registers? /dev/mem is an image of the computer's main memory, so that's not what you're looking for. You can read the contents of CPU registers using a debugger such as gdb, or you can write a program in assembly that will output register contents on the terminal.

It would really be pointless to look at CPU registers from the shell level. By the time you saw the values, they would have changed a gzillion times. If you are talking about seeing the values of memory mapped IO registers, or IO-space registers of x86 CPUs, then you should be able to write a simple program that uses the /dev/mem or /dev/port facility, and call it from a shell commandline. That would require root privileges.
A debugger such as gdb will expose such data as moo-cow has already pointed out.
--- rod.