src/soc/simulator/qemu.py

   1 from pygdbmi.gdbcontroller import GdbController
   2 import subprocess
   3
   4 launch_args_be = ['qemu-system-ppc64',
   5                '-machine', 'powernv9',
   6                '-nographic',
   7                '-s', '-S']
   8
   9 launch_args_le = ['qemu-system-ppc64le',
  10                '-machine', 'powernv9',
  11                '-nographic',
  12                '-s', '-S']
  13
  14 def swap_order(x, nbytes):
  15     x = x.to_bytes(nbytes, byteorder='little')
  16     x = int.from_bytes(x, byteorder='big', signed=False)
  17     return x
  18
  19
  20 class QemuController:
  21     def __init__(self, kernel, bigendian):
  22         if bigendian:
  23             args = launch_args_be + ['-kernel', kernel]
  24         else:
  25             args = launch_args_le + ['-kernel', kernel]
  26         self.qemu_popen = subprocess.Popen(args,
  27                                            stdout=subprocess.PIPE,
  28                                            stdin=subprocess.PIPE)
  29         self.gdb = GdbController(gdb_path='powerpc64-linux-gnu-gdb')
  30         self.bigendian = bigendian
  31
  32     def __enter__(self):
  33         return self
  34
  35     def __exit__(self, type, value, traceback):
  36         self.exit()
  37
  38     def connect(self):
  39         return self.gdb.write('-target-select remote localhost:1234')
  40
  41     def set_endian(self, bigendian):
  42         if bigendian:
  43             cmd = '-gdb-set endian big'
  44         else:
  45             cmd = '-gdb-set endian little'
  46         return self.gdb.write(cmd)
  47
  48     def break_address(self, addr):
  49         cmd = '-break-insert *0x{:x}'.format(addr)
  50         return self.gdb.write(cmd)
  51
  52     def delete_breakpoint(self, breakpoint=None):
  53         breakstring = ''
  54         if breakpoint:
  55             breakstring = f' {breakpoint}'
  56         return self.gdb.write('-break-delete' + breakstring)
  57
  58     def set_byte(self, addr, v):
  59         print ("qemu set byte", hex(addr), hex(v))
  60         faddr = '&{int}0x%x' % addr
  61         res = self.gdb.write('-data-write-memory-bytes %s "%02x"' % (faddr, v))
  62         print ("confirm", self.get_mem(addr, 1))
  63
  64     def get_mem(self, addr, nbytes):
  65         res = self.gdb.write("-data-read-memory %d u 1 1 %d" % (addr, 8*nbytes))
  66         #print ("get_mem", res)
  67         for x in res:
  68             if(x["type"]=="result"):
  69                 l = list(map(int, x['payload']['memory'][0]['data']))
  70                 res = []
  71                 for j in range(0, len(l), 8):
  72                     b = 0
  73                     for i, v in enumerate(l[j:j+8]):
  74                         b += v << (i*8)
  75                     res.append(b)
  76                 return res
  77         return None
  78
  79     def get_registers(self):
  80         return self.gdb.write('-data-list-register-values x')
  81
  82     def _get_register(self, fmt):
  83         res = self.gdb.write('-data-list-register-values '+fmt,
  84                              timeout_sec=1.0) # increase this timeout if needed
  85         for x in res:
  86             if(x["type"]=="result"):
  87                 assert 'register-values' in x['payload']
  88                 res = int(x['payload']['register-values'][0]['value'], 0)
  89                 return res
  90                 #return swap_order(res, 8)
  91         return None
  92
  93     # TODO: use -data-list-register-names instead of hardcoding the values
  94     def get_pc(self): return self._get_register('x 64')
  95     def get_msr(self): return self._get_register('x 65')
  96     def get_cr(self): return self._get_register('x 66')
  97     def get_lr(self): return self._get_register('x 67')
  98     def get_ctr(self): return self._get_register('x 68') # probably
  99     def get_xer(self): return self._get_register('x 69')
 100     def get_fpscr(self): return self._get_register('x 70')
 101     def get_mq(self): return self._get_register('x 71')
 102     def get_register(self, num):
 103         return self._get_register('x {}'.format(num))
 104
 105     def step(self):
 106         return self.gdb.write('-exec-next-instruction')
 107
 108     def gdb_continue(self):
 109         return self.gdb.write('-exec-continue')
 110
 111     def gdb_eval(self, expr):
 112         return self.gdb.write(f'-data-evaluate-expression {expr}')
 113
 114     def exit(self):
 115         self.gdb.exit()
 116         self.qemu_popen.kill()
 117         outs, errs = self.qemu_popen.communicate()
 118         self.qemu_popen.stdout.close()
 119         self.qemu_popen.stdin.close()
 120
 121
 122 def run_program(program, initial_mem=None, extra_break_addr=None,
 123                          bigendian=False):
 124     q = QemuController(program.binfile.name, bigendian)
 125     q.connect()
 126     q.set_endian(True) # easier to set variables this way
 127
 128     # Run to the start of the program
 129     if initial_mem:
 130         for addr, (v, wid) in initial_mem.items():
 131             for i in range(wid):
 132                 q.set_byte(addr+i, (v>>i*8) & 0xff)
 133
 134     # set breakpoint at start
 135     q.break_address(0x20000000)
 136     q.gdb_continue()
 137     # set the MSR bit 63, to set bigendian/littleendian mode
 138     msr = q.get_msr()
 139     print ("msr", bigendian, hex(msr))
 140     if bigendian:
 141         msr &= ~(1<<0)
 142         msr = msr & ((1<<64)-1)
 143     else:
 144         msr |= (1<<0)
 145     q.gdb_eval('$msr=%d' % msr)
 146     print ("msr set to", hex(msr))
 147     # set the CR to 0, matching the simulator
 148     q.gdb_eval('$cr=0')
 149     # delete the previous breakpoint so loops don't screw things up
 150     q.delete_breakpoint()
 151     # run to completion
 152     q.break_address(0x20000000 + program.size())
 153     # or to trap
 154     q.break_address(0x700)
 155     # or to alternative (absolute) address)
 156     if extra_break_addr:
 157         q.break_address(extra_break_addr)
 158     q.gdb_continue()
 159     q.set_endian(bigendian)
 160
 161     return q
 162
 163
 164 if __name__ == '__main__':
 165     q = QemuController("simulator/qemu_test/kernel.bin", bigendian=True)
 166     q.connect()
 167     q.break_address(0x20000000)
 168     q.gdb_continue()
 169     print(q.get_register(1))
 170     print(q.step())
 171     print(q.get_register(1))
 172     q.exit()