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comparison python/arm_cm3.py @ 202:f22b431f4113

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Added arm add instruction
author Windel Bouwman
date Sat, 15 Jun 2013 10:02:50 +0200
parents
children ca1ea402f6a1
comparison
equal deleted inserted replaced
201:d5debbfc0200 202:f22b431f4113
1 from target import Register, Instruction, Target
2 from asmnodes import ASymbol, ANumber
3 from ppci import CompilerError
4 import struct, types
5
6 def u16(h):
7 return struct.pack('<H', h)
8
9 armtarget = Target('arm')
10
11 # Add a custom operand mapping method:
12 def mapOp(self, operand):
13 if type(operand) is ASymbol:
14 # try to map to register:
15 regs = {}
16 for r in self.registers:
17 regs[r.name] = r
18 if operand.name in regs:
19 reg = regs[operand.name]
20 return reg
21 elif type(operand) is ANumber:
22 return ArmImm(operand.number)
23 raise CompilerError('Cannot map {0}'.format(operand))
24
25 armtarget.mapOperand = types.MethodType(mapOp, armtarget)
26
27 # Define:
28 registers = 'r0,r1,r2,r3,r4,r5'
29
30 class ArmReg(Register):
31 def __init__(self, num, name):
32 super().__init__(name)
33 self.num = num
34
35 class ArmImm:
36 def __init__(self, i):
37 self.i = i
38
39 # 8 bit registers:
40 r4 = ArmReg(4, 'r4')
41 armtarget.registers.append(r4)
42
43 class ArmInstruction(Instruction):
44 pass
45
46 @armtarget.instruction
47 class ldr_ins(ArmInstruction):
48 mnemonic = 'ldr'
49 opcode = 1337
50
51
52 @armtarget.instruction
53 class mov_ins(ArmInstruction):
54 """ mov Rd, imm8, move immediate value into register """
55 mnemonic = 'mov'
56 opcode = 4 # 00100
57 operands = (ArmReg, ArmImm)
58 def __init__(self, r, imm):
59 self.imm = imm.i
60 self.r = r.num
61 def encode(self):
62 rd = self.r
63 opcode = self.opcode
64 imm8 = self.imm
65 h = (opcode << 11) | (rd << 8) | imm8
66 return u16(h)
67
68
69 @armtarget.instruction
70 class yield_ins(ArmInstruction):
71 operands = ()
72 mnemonic = 'yield'
73 def encode(self):
74 return u16(0xbf10)
75