Make it run

The code in Figure 1 can be compiled and run.

Assuming that the program is stored in a file hello.vhdl, compiling can be done as

ghdl -a hello.vhdl

The above command generates the file hello.o, which can be elaborated, using the command

ghdl -e hello_world

where the string hello_world refers to the name of the entity in Figure 1.

The code can now be run, by doing

ghdl -r hello_world

which results in the printout

Hello, world