jakub-maleta

asm/asm.js

@@ -17,7 +17,7 @@
  */
 
 const fs = require('fs');
-const readline = require('readline');
+const readline = require('readline')
 
 // Process command line
 

ls8/cpu.py

@@ -2,29 +2,63 @@
 
 import sys
 
+hlt = 0b00000001
+ldi = 0b10000010
+prn = 0b01000111
+add = 0b10100000
+mul = 0b10100010
+push = 0b01000101
+pop = 0b01000110
+call = 0b01010000
+ret = 0b00010001
+
 class CPU:
     """Main CPU class."""
 
     def __init__(self):
         """Construct a new CPU."""
-        pass
-
-    def load(self):
+        self.ram = [0] * 256
+        self.pc = 0
+        self.registers = [0] * 8
+
+        self.branchtable = {
+           hlt : self.handle_hlt,
+           ldi : self.handle_ldi,
+           prn : self.handle_prn,
+           add : self.handle_add,
+           mul : self.handle_mul,
+           push : self.handle_push,
+           pop : self.handle_pop,
+           call : self.handle_call,
+           ret : self.handle_ret
+        }
+
+    def ram_read(self, address):
+        return self.ram[address]
+
+    def ram_write(self, value, address):
+        self.ram[address] = value
+
+    def load(self, filename):
         """Load a program into memory."""
 
-        address = 0
+        program = []
 
-        # For now, we've just hardcoded a program:
+        try:
+            with open(filename) as f:
+                for line in f:
+                    comment_split = line.split("#")
+                    num = comment_split[0].strip()
+                    if len(num) == 0:
+                        continue
+                    value = int(num, 2)
+                    program.append(value)
 
-        program = [
-            # From print8.ls8
-            0b10000010, # LDI R0,8
-            0b00000000,
-            0b00001000,
-            0b01000111, # PRN R0
-            0b00000000,
-            0b00000001, # HLT
-        ]
+        except FileNotFoundError:
+            print(f"{filename} not found")
+            sys.exit(2)
+
+        address = 0
 
         for instruction in program:
             self.ram[address] = instruction
@@ -60,6 +94,65 @@ def trace(self):
 
         print()
 
+    def handle_hlt(self, operand_a, operand_b):
+        sys.exit(0)
+
+    def handle_ldi(self, operand_a, operand_b):
+        self.registers[operand_a] = operand_b
+
+    def handle_prn(self, operand_a, operand_b):
+        print(self.registers[operand_a])
+
+    def handle_add(self, operand_a, operand_b):
+        self.registers[operand_a] +=  self.registers[operand_b]
+
+    def handle_mul(self, operand_a, operand_b):
+        self.registers[operand_a] *=  self.registers[operand_b]
+
+    def handle_push(self, operand_a, operand_b):
+        reg = operand_a
+        val = self.registers[reg]
+        # move stack pointer
+        self.registers[7] -= 1
+        # set value in sp position in ram to val 
+        self.ram[self.registers[7]] = val
+
+    def handle_pop(self, operand_a, operand_b):
+        reg = operand_a
+        val = self.ram[self.registers[7]]
+        # set value in given register to val from stack
+        self.registers[reg] = val
+        # move stack pointer
+        self.registers[7] += 1 
+
+    def handle_call(self, operand_a, operand_b):
+        # move stack pointer
+        self.registers[7] -= 1
+        # set top value in stack to the position to return
+        self.ram[self.registers[7]] = self.pc + 2
+        # set pc to the position stored in register
+        self.pc = self.registers[operand_a]
+
+    def handle_ret(self, operand_a, operand_b):
+        # store top value from the stack in pc
+        self.pc = self.ram[self.registers[7]] 
+        # move stack pointer
+        self.registers[7] += 1
+
     def run(self):
         """Run the CPU."""
-        pass
+
+        self.registers[7] = 0xF3
+
+        while True:
+            ir = self.ram[self.pc]
+            operand_a = self.ram[self.pc + 1]
+            operand_b = self.ram[self.pc + 2]
+
+            ops_to_skip = 0
+            if ir != call and ir != ret:
+                ops_to_skip = (ir >> 6) + 1
+
+            self.branchtable[ir](operand_a, operand_b)
+
+            self.pc += ops_to_skip

ls8/examples/list.txt

@@ -0,0 +1,12 @@
+call:
+  print 10 + 10 = 20,
+  print 15 + 15 =  30
+  print 18 + 18 =  36
+  print 30 + 30 =  60
+
+  It implements printing, adding, calls
+
+interrupts:
+
+keyboard:
+

ls8/ls8.py

@@ -5,7 +5,11 @@
 import sys
 from cpu import *
 
+if len(sys.argv) != 2:
+    print("usage: ls8.py <filename>")
+    sys.exit(1)
+
 cpu = CPU()
 
-cpu.load()
+cpu.load(sys.argv[1])
 cpu.run()