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import sys, socket
start_halted = True
def init():
global client
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind(('127.0.0.1', 1234))
sock.listen()
print('Listening for gdb on', sock.getsockname(), file=sys.stderr)
client, peer = sock.accept()
sock.close()
print('Accepted connection from', peer, file=sys.stderr)
buffer = b''
haltFromStop = False
def halt():
global buffer, haltFromStop
if haltFromStop:
reply(b'S05')
haltFromStop = True
while True:
data = client.recv(4096)
if not data:
break
buffer = buffer + data if buffer else data
try:
start = buffer.index(b'$')
marker = buffer.index(b'#', start + 1)
except ValueError:
continue
if marker + 2 >= len(buffer):
continue
data = buffer[start + 1:marker]
cksum = int(buffer[marker + 1:marker + 3], 16)
if cksum != (sum(data) & 0xff):
raise Exception(f'bad packet checksum: {buffer[start:marker + 3]}')
buffer = buffer[marker + 3:]
client.send(b'+')
if data == b'?':
out = b'S05'
elif data == b'c':
return 'continue'
elif data == b'D':
out = b'OK'
elif data == b'g':
out = hexout(read_reg(gdb_reg(r)) for r in range(16))
elif data[0] == b'm'[0]:
addr, length = (int(x, 16) for x in data[1:].split(b','))
out = hexout(read_mem(addr, length))
elif data[0] == b'M'[0]:
addrlen, data = data[1:].split(b':')
addr, length = (int(x, 16) for x in addrlen.split(b','))
data = bytes.fromhex(str(data, 'ascii'))
assert len(data) == length
write_mem(addr, data)
out = b'OK'
elif data[0] == b'p'[0]:
reg = gdb_reg(int(data[1:], 16))
out = hexout(read_reg(reg) if reg is not None else None)
elif data == b's':
return 'step'
else:
print('unhandled packet:', data, file=sys.stderr)
out = b''
reply(out)
def reply(out):
client.send(b'$' + out + b'#' + hexout(sum(out) & 0xff, 1))
def gdb_reg(n):
if 0 <= n < 8:
return (r0, r1, r2, r3, r4, r5, r6, r7)[n]
if n == 15:
return pc
if n == 0x19:
return cpsr
mode = read_reg(cpsr) & 0b11111
if 8 <= n < 13:
if mode == 0b10001:
regs = (r8_fiq, r9_fiq, r10_fiq, r11_fiq, r12_fiq)
else:
regs = (r8_usr, r9_usr, r10_usr, r11_usr, r12_usr)
return regs[n - 8]
if 13 <= n < 15:
if mode == 0b10011:
regs = (r13_svc, r14_svc)
elif mode == 0b10111:
regs = (r13_abt, r14_abt)
elif mode == 0b11011:
regs = (r13_und, r14_und)
elif mode == 0b10010:
regs = (r13_irq, r14_irq)
elif mode == 0b10001:
regs = (r13_fiq, r14_fiq)
else:
regs = (r13_usr, r14_usr)
return regs[n - 13]
print('bad gdb regnum:', n, file=sys.stderr)
return None
def hexout(data, size=4):
if data is None:
return b''
elif type(data) is bytes:
return data.hex().encode('ascii')
elif type(data) is int:
return data.to_bytes(size, 'little').hex().encode('ascii')
return b''.join(hexout(d) for d in data)
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