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sasm
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sasm
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#!/usr/bin/env python3
#chmod a+x sasm <- when restarting terminal
#PATH=$PATH:.
# for future reference call using -> ./sasm [filename1] [filename2] filename1 = file with assembly code for sic/XE filename2 = output file for object code
"""
DATE: May 15 2020
AUTH: Madison Monroe
FILE: program.py
DESC: Assembler passes 1 and 2. Generates object code when given a SIC or SIC/XE program
"""
import sys
import os
import math
indirect = False
immediate = False
indexed = False
extended = False
arrofbytes = []
locctr = 0
registers = ['A', 'X', 'B', 'S', 'L', 'T', 'F', 'PC', 'SW']
registervals = [0, 1, 3, 4, 2, 5, 6, 8, 9]
allowablechars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890:_'"
alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
symtab = {}
optable = {
"ADD" : ["m", "3 4", int("18", 16)],
"ADDF" : ["m", "3 4", int("58", 16)],
"ADDR" : ["r r", "2", int("90", 16)],
"AND" : ["m", "3 4", int("40", 16)],
"CLEAR" : ["r", "2", int("B4",16)],
"COMP" : ["m", "3 4", int("28", 16)],
"COMPF" : ["m", "3 4", int("88", 16)],
"COMPR" : ["r r", "2", int("A0", 16)],
"DIV" : ["m", "3 4", int("24", 16)],
"DIVF" : ["m", "3 4", int("64", 16)],
"DIVR" : ["r r", "2", int("9C", 16)],
"FIX" : ["", "1", int("C4", 16)],
"FLOAT" : ["", "1", int("C0", 16)],
"HIO" : ["", "1", int("F4", 16)],
"J" : ["m", "3 4", int("3C", 16)],
"JEQ" : ["m", "3 4", int("30", 16)],
"JGT" : ["m", "3 4", int("34", 16)],
"JLT" : ["m", "3 4", int("38", 16)],
"JSUB" : ["m", "3 4", int("48", 16)],
"LDA" : ["m", "3 4", int("00", 16)],
"LDB" : ["m", "3 4", int("68", 16)],
"LDCH" : ["m", "3 4", int("50", 16)],
"LDF" : ["m", "3 4", int("70", 16)],
"LDL" : ["m", "3 4", int("08", 16)],
"LDS" : ["m", "3 4", int("6C", 16)],
"LDT" : ["m", "3 4", int("74", 16)],
"LDX" : ["m", "3 4", int("04", 16)],
"LPS" : ["m", "3 4", int("D0", 16)],
"MUL" : ["m", "3 4", int("20", 16)],
"MULF" : ["m", "3 4", int("60", 16)],
"MULR" : ["r r", "2", int("98", 16)],
"NORM" : ["", "1", int("C8", 16)],
"OR" : ["m", "3 4", int("44", 16)],
"RD" : ["m", "3 4", int("D8", 16)],
"RMO" : ["r r", "2", int("AC", 16)],
"RSUB" : ["", "3 4", int("4C", 16)],
"SHIFTL" : ["r n", "2", int("A4", 16)],
"SHIFTR" : ["r n", "2", int("A8", 16)],
"SIO" : ["", "1", int("F0", 16)],
"SSK" : ["m", "3 4", int("EC", 16)],
"STA" : ["m", "3 4", int("0C", 16)],
"STB" : ["m", "3 4", int("78", 16)],
"STCH" : ["m", "3 4", int("54", 16)],
"STF" : ["m", "3 4", int("80", 16)],
"STI" : ["m", "3 4", int("D4", 16)],
"STL" : ["m", "3 4", int("14", 16)],
"STS" : ["m", "3 4", int("7C", 16)],
"STSW" : ["m", "3 4", int("E8", 16)],
"STT" : ["m", "3 4", int("84", 16)],
"STX" : ["m", "3 4", int("10", 16)],
"SUB" : ["m", "3 4", int("1C", 16)],
"SUBF" : ["m", "3 4", int("5C", 16)],
"SUBR" : ["r r", "2", int("94", 16)],
"SVC" : ["n", "2", int("B0", 16)],
"TD" : ["m", "3 4", int("E0", 16)],
"TIO" : ["", "1", int("F8", 16)],
"TIX" : ["m", "3 4", int("2C", 16)],
"TIXR" : ["r", "2", int("B8", 16)],
"WD" : ["m", "3 4", int("DC", 16)],
}
#splits array so ex [label:abc, ...] becomes [label:, abc, ...]
def processcolon(arr):
count = 0
for i in arr:
for char in i:
if char == ':':
count = count + 1
if count > 1:
print("Error")
sys.exit(1)
exit = False
#splitting after label
if count == 1:
for i in range(len(arr)):
if exit:
break
for j in range(len(arr[i])):
if arr[i][j] == ':' and len(arr[i]) > j + 1:
split = arr[i][j +1:]
arr[i] = arr[i][:j+ 1]
arr.insert(i + 1, split)
exit = True
break
return arr
#splits arr so that symbol is a seperate entity
def FindAndSplit(arr, symbol):
count = 0
for i in arr:
for char in i:
if char == symbol:
count = count + 1
if count > 1:
print("Error. Exiting...")
sys.exit(1)
if count == 1:
for i in range(len(arr)):
if arr[i] == symbol:
break
if arr[i][0] == symbol:
arr[i] = arr[i][1:]
arr.insert(i, symbol)
break
elif arr[i][-1] == symbol:
arr[i] = arr[i][:-1]
arr.insert(i + 1, symbol)
break
if symbol == ',':
for j in range(len(arr[i])):
curr = arr[i]
if curr[j] == symbol:
endofarr = arr[i+1:]
arr = arr[:i]
arr.append(curr[:j])
arr.append(curr[j])
arr.append(curr[j+1:])
arr = arr + endofarr
return arr
return arr
def updateLocctr(val, line):
global locctr
locctr = locctr + val
if locctr > 1048576: #100000 in decimal
print("Instruction ends beyond maximum memory address for SIC/XE:\n" + line)
sys.exit(1)
def checkHex(val):
try:
val = int(val, 16)
except ValueError:
print("Error. Not a hex digit.")
sys.exit(1)
return True
def printSorted(symtab):
print("Symbols:")
for i in sorted(symtab):
print(" " + i + ": " + symtab[i])
def containsLabel(arr):
if len(arr) > 0:
first = arr[0]
if first[-1] == ":":
return True
return False
def getLabel(arr):
assert containsLabel(arr), "Does not contain label"
label = arr[0]
label = label[:-1] # chops off :
#check to make sure label is allowed
for char in label:
if not char.upper().isalnum() and not char == '_':
print(char + " is not allowed in label.")
sys.exit(1)
if label[0].upper() not in alphabet and label[0].upper() != "_":
print(label[0] + " cannot be the first character in a label.")
sys.exit(1)
return label
def removeSymbol(symbol, arr):
if containsLabel(arr):
index = 1
else:
index = 0
if len(arr) >= index + 1 and arr[index] == symbol:
del arr[index]
return True
elif len(arr) >= index + 1 and arr[index][0] == symbol:
val = arr[index][0]
val = arr[index][1:]
arr[index] = val
if symbol in arr:
print(symbol + " cannot be used this way. Exiting...")
sys.exit(1)
return True
return False
def checkForPunctuation(arr, line):
containsat = '@' in line
containspound = '#' in line
if containsat and containspound:
print("Error with \n" + line + " Exiting...")
sys.exit(1)
if containsat:
arr = FindAndSplit(arr, '@')
elif containspound:
arr = FindAndSplit(arr, '#')
def isCommentLine(str):
nonwhitespace = False
for char in str:
if not nonwhitespace and char == ".":
return True
if char != " ":
nonwhitespace = True
return False
def tabify(str):
loc = 0
newstr = ""
for char in str:
if char == "\t":
while True:
newstr = newstr + " "
loc += 1
if (loc % 8) == 0:
break
else:
newstr = newstr + char
loc += 1
return newstr
def processlinep2(line):
global indirect
global immediate
global extended
global indexed
if line != "\n":
occur1 = line.upper().find("C'")
occur2 = line[occur1 + 2:].find("\'") + occur1 + 2
if occur1 != -1 and occur2 != -1:
contents = line[occur1:occur2 + 1]
line = line[:occur1] + "C''" + line[occur2 + 1:]
arr = line.split()
arr = FindAndSplit(arr, ',')
arr = processcolon(arr)
for i in range(len(arr)):
if arr[i] == "C''":
arr[i] = contents
elif occur1 == -1 or occur2 == -1:
arr = line.split()
arr = FindAndSplit(arr, ',')
arr = processcolon(arr)
if removeSymbol('+', arr):
extended = True
else:
extended = False
indirect = '@' in line
immediate = '#' in line
if indirect:
arr = FindAndSplit(arr, '@')
elif immediate:
arr = FindAndSplit(arr, '#')
return arr
return 0
def outputHeader(arr, index, locctr, file):
arrofheaderbytes = []
startloc = 0
arrofheaderbytes.append(ord("H"))
if index == 1:
name = arr[0][:-1]
else:
name = ""
name = name[:6]
numspaces = 6 - len(name) # + 1 needed so : is not included in calculations
for i in range(numspaces):
arrofheaderbytes.append(ord(" "))
for char in name:
arrofheaderbytes.append(ord(char))
if (len(arr) == index + 2) and arr[index].upper() == "START":
val = arr[index + 1]
startloc = int(val, 16)
byte1 = startloc & 255
byte2 = startloc >> 8
byte2 = byte2 & 255
byte3 = startloc >> 16
byte3 = byte3 & 255
else:
byte1 = 0
byte2 = 0
byte3 = 0
arrofheaderbytes.append(byte3)
arrofheaderbytes.append(byte2)
arrofheaderbytes.append(byte1)
x = locctr - startloc
byte1 = x & 255
byte2 = x >> 8
byte2 = byte2 & 255
byte3 = x >> 16
byte3 = byte3 & 255
arrofheaderbytes.append(byte3)
arrofheaderbytes.append(byte2)
arrofheaderbytes.append(byte1)
arrofheaderbytes = bytearray(arrofheaderbytes)
file.write(arrofheaderbytes)
def getSymbol(arr, index, list):
if list[0] == 'm':
if len(arr) == index + 2 or len(arr) == index + 3: # for ex. stl @ label or stl label
return arr[-1]
elif len(arr) == index + 1: # for stl
return ""
else: # for stl @ label , x or stl label, x
return arr[-3]
return ""
def type1(opcode):
global arrofbytes
arrofbytes.append(opcode)
def type2(opcode, reg1, reg2):
global arrofbytes
arrofbytes.append(opcode)
byte2 = reg1
byte2 = byte2 << 4
byte2 = byte2 + reg2
arrofbytes.append(byte2)
def type3(opcode, indirect, immediate, indexed, base, pc, disp):
global arrofbytes
byte = opcode >> 2 #shifr twice to divide by 4
byte = byte << 1
if indirect:
byte = byte + 1
byte = byte << 1
elif immediate:
byte = byte << 1
byte = byte + 1
else:
byte = byte + 1
byte = byte << 1
byte = byte + 1
arrofbytes.append(byte)
byte2 = 0
if indexed:
byte2 = byte2 + 1
byte2 = byte2 << 1
if base:
byte2 = byte2 + 1
byte2 = byte2 << 1
if pc:
byte2 = byte2 + 1
byte2 = byte2 << 1
byte2 = byte2 << 1 # bc the E byte is never set
for i in range(4):
val = disp >> 11 - i
val = val & 1
if val == 1:
byte2 = byte2 + 1
byte2 = byte2 << 1
byte2 = byte2 >> 1 # prevents it from being shifted once too much
arrofbytes.append(byte2)
byte3 = disp & 255 #11111111b in decimal (preserves only the last 8 bits)
arrofbytes.append(byte3)
def type4(opcode, indirect, immediate, indexed, base, pc, address):
global arrofbytes
byte = opcode >> 2 #shifr twice to divide by 4
byte = byte << 1
if indirect:
byte = byte + 1
byte = byte << 1
elif immediate:
byte = byte << 1
byte = byte + 1
else:
byte = byte + 1
byte = byte << 1
byte = byte + 1
arrofbytes.append(byte)
byte2 = 0
if indexed:
byte2 = byte2 + 1
byte2 = byte2 << 1
if base:
byte2 = byte2 + 1
byte2 = byte2 << 1
if pc:
byte2 = byte2 + 1
byte2 = byte2 << 1
byte2 = byte2 + 1 # setting E bit
byte2 = byte2 << 1
for i in range(4):
val = address >> 15 - i
val = val & 1
if val == 1:
byte2 = byte2 + 1
byte2 = byte2 << 1
byte2 = byte2 >> 1 # prevents it from being shifted once too much
arrofbytes.append(byte2)
byte4 = address & 255 #11111111b in decimal (preserves only the last 8 bits)
byte3 = address
byte3 = byte3 >> 8
byte3 = byte3 & 255
arrofbytes.append(byte3)
arrofbytes.append(byte4)
def sic(opcode, X, address):
global arrofbytes
arrofbytes.append(opcode)
byte2 = 0
if X:
byte2 = byte2 + 1
byte2 = byte2 << 1
for i in range(7):
val = address >> 14 - i
val = val & 1
if val == 1:
byte2 = byte2 + 1
byte2 = byte2 << 1
byte2 = byte2 >> 1
arrofbytes.append(byte2)
byte3 = address & 255
arrofbytes.append(byte3)
def pcrelative(opcode, indirect, immediate, indexed, address, locctr):
global arrofbytes
#calculate displacement
disp = address - locctr
if abs(disp) > 2048:
return False
byte = opcode >> 2 #shifr twice to divide by 4
byte = byte << 1
if indirect:
byte = byte + 1
byte = byte << 1
elif immediate:
byte = byte << 1
byte = byte + 1
else:
byte = byte + 1
byte = byte << 1
byte = byte + 1
arrofbytes.append(byte)
byte2 = 0
if indexed:
byte2 = byte2 + 1
byte2 = byte2 << 2 # shift twice bc base bit never set
byte2 = byte2 + 1 # setting pc byte
byte2 = byte2 << 2 # shift twice bc the E byte is never set
for i in range(4):
val = disp >> 11 - i
val = val & 1
if val == 1:
byte2 = byte2 + 1
byte2 = byte2 << 1
byte2 = byte2 >> 1 # prevents it from being shifted once too much
arrofbytes.append(byte2)
byte3 = disp & 255 #11111111b in decimal (preserves only the last 8 bits)
arrofbytes.append(byte3)
return True
def basemode(opcode, indirect, immediate, indexed, address, B):
global arrofbytes
disp = address - B
if disp > 4096:
return False
byte = opcode >> 2 #shifr twice to divide by 4
byte = byte << 1
if indirect:
byte = byte + 1
byte = byte << 1
elif immediate:
byte = byte << 1
byte = byte + 1
else:
byte = byte + 1
byte = byte << 1
byte = byte + 1
arrofbytes.append(byte)
byte2 = 0
if indexed:
byte2 = byte2 + 1
byte2 = byte2 << 1
byte2 = byte2 + 1
byte2 = byte2 << 3 # shift 3 times bc never pc and e bit never set
for i in range(4):
val = disp >> 11 - i
val = val & 1
if val == 1:
byte2 = byte2 + 1
byte2 = byte2 << 1
byte2 = byte2 >> 1 # prevents it from being shifted once too much
arrofbytes.append(byte2)
byte3 = disp & 255 #11111111b in decimal (preserves only the last 8 bits)
arrofbytes.append(byte3)
return True
def outputTextRecord(objcode, textrecstartloc, file, locctr):
arrofbytes = []
arrofbytes.append(ord("T"))
byte1 = textrecstartloc & 255
byte2 = textrecstartloc >> 8
byte2 = byte2 & 255
byte3 = textrecstartloc >> 16
byte3 = byte3 & 255
arrofbytes.append(byte3)
arrofbytes.append(byte2)
arrofbytes.append(byte1)
length = locctr - textrecstartloc
byte1 = length & 255
arrofbytes.append(byte1)
arrofbytes = bytearray(arrofbytes)
file.write(arrofbytes)
objcode = bytearray(objcode)
file.write(objcode)
def outputEnd(startloc, file):
arrofbytes = []
arrofbytes.append(ord("E"))
byte1 = startloc & 255
byte2 = startloc >> 8
byte2 = byte2 & 255
byte3 = startloc >> 16
byte3 = byte3 & 255
arrofbytes.append(byte3)
arrofbytes.append(byte2)
arrofbytes.append(byte1)
arrofbytes = bytearray(arrofbytes)
file.write(arrofbytes)
def pass2():
global arrofbytes
global locctr
global extended
global indirect
global indexed
global immediate
textrecstartloc = 0
base = False
maxloc = locctr
locctr = 0
startprocessed = False
objectfile = open(sys.argv[2], "wb")
intermediatefile = open("intermediatefile.txt", "r")
while True:
line = intermediatefile.readline()
arr = processlinep2(line)
if arr != 0:
if not ((len(arr) == 1 and containsLabel(arr)) or len(arr) < 1):
if containsLabel(arr):
index = 1
else:
index = 0
if len(arr) >= index + 3 and arr[-1].upper() == "X" and arr[-2] == ",":
indexed = True
else:
indexed = False
opcode = arr[index].upper()
if opcode == "START":
outputHeader(arr, index, maxloc, objectfile)
startprocessed = True
if len(arr) == index + 2:
textrecstartloc = int(arr[index + 1], 16)
locctr = int(arr[index + 1], 16)
elif opcode in optable:
list = optable[arr[index].upper()]
if list[0] == 'm':
symbol = getSymbol(arr, index, list)
if symbol == "":
address = 0
elif symbol.isdigit():
address = int(symbol)
elif symbol.upper() not in symtab:
print("Error." + symbol + " not in symbol table.\n" + line)
sys.exit(1)
else:
address = int(symtab[symbol.upper()], 16)
if extended:
locctr = locctr + 4
type4(list[2], indirect, immediate, indexed, False, False, address)
else:
locctr = locctr + 3
if not (base and basemode(list[2], indirect, immediate, indexed, address, Breg)):
if not pcrelative(list[2], indirect, immediate, indexed, address, locctr):
if address <= 4096:
type3(list[2], indirect, immediate, indexed, False, False, address)
elif address <= 32768:
sic(list[2], indexed, address)
else:
print("Extended mode is needed")
sys.exit(1)
elif list[0] == "r r":
reg1 = arr[index + 1].upper()
reg2 = arr[-1].upper()
locctr = locctr + 2
for i in range(len(registers)):
if registers[i] == reg1:
reg1 = registervals[i]
if registers[i] == reg2:
reg2 = registervals[i]
type2(list[2], reg1, reg2)
elif list[0] == "r":
reg1 = arr[-1].upper()
locctr = locctr + 2
for i in range(len(registers)):
if registers[i] == reg1:
reg1 = registervals[i]
type2(list[2], reg1, 0)
elif list[0] == "r n":
reg1 = arr[index + 1].upper()
locctr = locctr + 2
nval = int(arr[index + 3])
for i in range(len(registers)):
if registers[i] == reg1:
reg1 = registervals[i]
type2(list[2], reg1, (nval - 1))
elif list[0] == "n":
nval = int(arr[-1])
locctr = locctr + 2
type2(list[2], nval, 0)
elif list[0] == "":
if opcode == "RSUB":
locctr = locctr + 3
type3(list[2], False, False, False, False, False, 0)
else:
locctr = locctr + 1
type1(list[2])
else:
print("this instruction is not currently allowed\n" + line)
sys.exit(0)
elif opcode == "WORD":
locctr = locctr + 3
x = int (arr[index + 1])
byte1 = x & 255
byte2 = x >> 8
byte2 = byte2 & 255
byte3 = x >> 16
byte3 = byte3 & 255
arrofbytes.append(byte3)
arrofbytes.append(byte2)
arrofbytes.append(byte1)
elif opcode == "BYTE":
if arr[index + 1].isdigit():
locctr = locctr + 1
arrofbytes.append(int(arr[index + 1]))
elif arr[-1][0].upper() == "C":
contents = arr[-1][2:-1]
for i in range(len(contents)):
val = contents[i]
arrofbytes.append(ord(val))
locctr = locctr + len(contents)
elif arr[-1][0].upper() == "X":
contents = arr[-1][2:-1]
size = len(contents) / 2
size = int(math.ceil(size))
locctr = locctr + size
bytes = []
val = int(contents, 16)
for i in range(size):
x = val & 255
bytes.append(x)
val = val >> 8
bytes.reverse()
for i in range(len(bytes)):
arrofbytes.append(bytes[i])
elif opcode == "RESW":
val = int(arr[index + 1])
if (locctr - textrecstartloc) > 0: #added in since last submit
outputTextRecord(arrofbytes, textrecstartloc, objectfile, locctr)
arrofbytes = []
locctr = locctr + (3 * val)
textrecstartloc = locctr
elif opcode == "RESB":
val = int(arr[index + 1])
if (locctr - textrecstartloc) > 0: #added in since last submit
outputTextRecord(arrofbytes, textrecstartloc, objectfile, locctr)
arrofbytes = []
locctr = locctr + val
textrecstartloc = locctr
elif opcode == "BASE":
base = True
Breg = int(arr[-1])
elif opcode == "NOBASE":
base = False
if not startprocessed:
outputHeader(arr, index, maxloc, objectfile)
startprocessed = True
if (locctr - textrecstartloc) > 64:
overflow = 1
temp = []
while True:
temp.append(arrofbytes[-overflow])
if locctr - overflow - textrecstartloc == 64:
break
overflow = overflow + 1
temp.reverse()
arrofbytes = arrofbytes[: -overflow]
outputTextRecord(arrofbytes, textrecstartloc, objectfile, locctr - overflow)
arrofbytes = []
for i in range(len(temp)):
arrofbytes.append(temp[i])
textrecstartloc = locctr - overflow
elif opcode == "END":
if (locctr - textrecstartloc) > 0:
outputTextRecord(arrofbytes, textrecstartloc, objectfile, locctr)
if len(arr) > index + 1:
label = arr[index + 1]
loc = int(symtab[label.upper()], 16)
else:
loc = 0
outputEnd(loc, objectfile)
sys.exit(0)
sys.exit(1)
def pass1():
global locctr
emptyfile = True
extendedmode = False
filepath = sys.argv[1]
intermediatefile = open("intermediatefile.txt", "w")
if not os.path.isfile(filepath):
print("File path {} does not exist. Exiting...".format(filepath))
sys.exit(1)
file = open(filepath, 'r')
while True:
line = file.readline()
line = tabify(line)
if isCommentLine(line):
line = "\n"
length = len(line)
line = line[:40]
if length > 40:
line = line + "\n"
arr = line.split()
if len(arr) > 0:
break
startprocessed = False
if line.upper().find("START") != -1:
startprocessed = False
for i in arr:
for char in i:
if char.upper() not in allowablechars:
print("Error symbol " + char +" not allowed in this context. Exiting...")
sys.exit(1)
first = arr[0]
if first[-1] == ":":
if len(arr) > 1 and arr[1].upper() == "START": # label is first thing and start is second
if len(arr) == 2: # nothing after START
locctr = 0
elif len(arr) == 3: # something after START
val = arr[2]
if checkHex(val):
val = int(val, 16)
if val > 1048575: #FFFFF is hex
print("The start value you enter cannot be larger than FFFFF. Exiting...")
file.close()
sys.exit(1)
updateLocctr(val, line)
else:
print(val + " is not an allowed digit. Exiting...")
file.close()
sys.exit(1)
if len(arr) > 3:
print("Extranious characters at the end of line. (", end = "")
for i in range(len(arr)):
if i > 2:
print(arr[i], end = " ")
print(")")
elif arr[1].upper() != "START":
print("Error with START on this line." + line + "Exiting...")
file.close()
sys.exit(1)
elif first.upper() == "START":
if len(arr) == 1:
locctr = 0
elif len(arr) == 2:
val = arr[1]
if checkHex(val):
val = int(val, 16)
if val > 1048575:
print("The start value you enter cannot be larger than FFFFF. Exiting...")
file.close()
sys.exit(1)
updateLocctr(val, line)
else:
print(val + " is not an allowed digit. Exiting...")
file.close()
sys.exit(1)
elif len (arr) > 2:
print("Extranious characters at the end of line. (")
for i in range(len(arr), end = ""):
if i > 2:
print(" {}").format(arr[i], end =" ")
print(")")
else: