The first thing you might want to do is to assemble some code and run it on the engine.
To do so you have to set up a Processor and the Assembler:
from py_register_macine2.machines.small import small_register_machine
from py_register_machine2.tools.assembler.assembler import Assembler
processor, rom, ram, flash = small_register_machine()
processor.setup_done()
small_register_machine returns a configured engine with 50 words ROM, 200 words RAM and 500 words Flash.
The size of a word is 64 bit.
Now you need a program, in this case we will use simple Hello, World program:
from io import StringIO
asm = '''\
ldi 'H' out0
ldi 'e' out0
ldi 'l' out0
ldi 'l' out0
ldi 'o' out0
ldi '!' out0
ldi 0xa out0
ldi 0b1 ECR'''
stream = StringIO(asm)
This will print Hello!\n to sys.stdout and stop the engine. The assembly language is KASM2.
The assembler will convert the assembly into machine code:
assembler = Assembler(processor, stream)
code = assembler.assemble()
The machine code is just a list of int objects that can be programmed to the
ROM or Flash device:
rom.program(code)
And then the Processor will execute the program:
processor.run()
Putting it all together:
from py_register_macine2.machines.small import small_register_machine
from py_register_machine2.tools.assembler.assembler import Assembler
processor, rom, ram, flash = small_register_machine()
processor.setup_done()
from io import StringIO
asm = '''\
ldi 'H' out0
ldi 'e' out0
ldi 'l' out0
ldi 'l' out0
ldi 'o' out0
ldi '!' out0
ldi 0xa out0
ldi 0b1 ECR'''
stream = StringIO(asm)
assembler = Assembler(processor, stream)
code = assembler.assemble()
rom.program(code)
processor.run()
Usually the ROM will be too small to hold the programs you want to execute, so those will be stored in the Flash.
To execute programs stored in the Flash one has to load them into RAM, this is done by the Code Loader(CL) or Boot Code Loader (BCL) stored in the ROM.
We will use the same setup like above:
from py_register_macine2.machines.small import small_register_machine
from py_register_machine2.tools.assembler.assembler import Assembler
from py_register_machine2.tools.assembler.directives import ConvertingDirective
from io import StringIO
processor, rom, ram, flash = small_register_machine()
processor.setup_done()
asm = '''\
.set flash_sec_size flash_sec_end
ldi 'H' out0
ldi 'e' out0
ldi 'l' out0
ldi 'l' out0
ldi 'o' out0
ldi '!' out0
ldi 0xa out0
ldi 0b1 ECR
flash_sec_end:
'''
stream = StringIO(asm)
# This directive will allow you to set one word to a special value
# used to get the size of the section
set_directive = ConvertingDirective(".set", lambda x: x)
assembler = Assembler(processor, stream, directives = [set_directive])
code = assembler.assemble()
The only new part is the size of the program, stored in the first word, now we will store the program in the Flash:
flash.program(code)
So now we need the CL:
cl = '''\
ldi 0 r0
in r0 r1
ldi RAMEND_LOW r2
loop:
inc r0
in r0 r3
pst r3 r2
inc r2
dec r1
jne r1 loop
sjmp RAMEND_LOW
'''
What does that code snippet?
At first it reads the size of the code section in the Flash device:
ldi 0 r0
in r0 r1
and sets up a pointer to the RAM word to write into:
ldi RAMEND_LOW r2
After that it copies the content from the Flash to the RAM using a do-while-loop. Finally it jumps to the first word in RAM:
sjmp RAMEND_LOW
The constant RAMEND_LOW is a processor constant and points to the first word of the RAM.
You are able to generate jump marks using <name>: (i.e. loop:).
Now you need to assemble and store the Code Loader:
stream = StringIO(cl)
assembler = Assembler(processor, stream)
code = assembler.assemble()
rom.program(code)
And run it:
processor.run()
Putting it all together:
from py_register_macine2.machines.small import small_register_machine
from py_register_machine2.tools.assembler.assembler import Assembler
from py_register_machine2.tools.assembler.directives import ConvertingDirective
from io import StringIO
processor, rom, ram, flash = small_register_machine()
processor.setup_done()
asm = '''\
.set flash_sec_size flash_sec_end
ldi 'H' out0
ldi 'e' out0
ldi 'l' out0
ldi 'l' out0
ldi 'o' out0
ldi '!' out0
ldi 0xa out0
ldi 0b1 ECR
flash_sec_end:
'''
stream = StringIO(asm)
# This directive will allow you to set one word to a special value
# used to get the size of the section
set_directive = ConvertingDirective(".set", lambda x: x)
assembler = Assembler(processor, stream, directives = [set_directive])
code = assembler.assemble()
flash.program(code)
cl = '''\
ldi 0 r0
in r0 r1
ldi RAMEND_LOW r2
loop:
inc r0
in r0 r3
pst r3 r2
inc r2
dec r1
jne r1 loop
sjmp RAMEND_LOW
'''
stream = StringIO(cl)
assembler = Assembler(processor, stream)
code = assembler.assemble()
rom.program(code)
processor.run()