X-Git-Url: https://sigrok.org/gitweb/?p=libsigrokdecode.git;a=blobdiff_plain;f=decoders%2Fjtag_stm32%2Fjtag_stm32.py;h=e30788c7dfc348b696213a25a2bc49014eb3798b;hp=1677a9332804eebf765306969056c436f74b4ad5;hb=d274e1bfc2cd0795c62ce304fa01320af16ca396;hpb=66a8517ecfea370741c5789d664c9a965b5c0bc2;ds=sidebyside diff --git a/decoders/jtag_stm32/jtag_stm32.py b/decoders/jtag_stm32/jtag_stm32.py index 1677a93..e30788c 100644 --- a/decoders/jtag_stm32/jtag_stm32.py +++ b/decoders/jtag_stm32/jtag_stm32.py @@ -23,12 +23,15 @@ import sigrokdecode as srd # JTAG debug port data registers (in IR[3:0]) and their sizes (in bits) +# Note: The ARM DAP-DP is not IEEE 1149.1 (JTAG) compliant (as per ARM docs), +# as it does not implement the EXTEST, SAMPLE, and PRELOAD instructions. +# Instead, BYPASS is decoded for any of these instructions. ir = { '1111': ['BYPASS', 1], # Bypass register '1110': ['IDCODE', 32], # ID code register '1010': ['DPACC', 35], # Debug port access register '1011': ['APACC', 35], # Access port access register - '1000': ['ABORT', 35], # Abort register + '1000': ['ABORT', 35], # Abort register # TODO: 32 bits? Datasheet typo? } # ARM Cortex-M3 r1p1-01rel0 ID code @@ -44,26 +47,79 @@ jtag_idcode = { 0x06418041: 'Connectivity-line device, rev. A/Z', } -# ACK[2:0] in the DPACC/APACC registers +# ACK[2:0] in the DPACC/APACC registers (unlisted values are reserved) ack_val = { - '000': 'Reserved', '001': 'WAIT', '010': 'OK/FAULT', - '011': 'Reserved', - '100': 'Reserved', - '101': 'Reserved', - '110': 'Reserved', - '111': 'Reserved', } # 32bit debug port registers (addressed via A[3:2]) -reg = { +dp_reg = { '00': 'Reserved', # Must be kept at reset value '01': 'DP CTRL/STAT', '10': 'DP SELECT', '11': 'DP RDBUFF', } +# APB-AP registers (each of them 32 bits wide) +apb_ap_reg = { + 0x00: ['CSW', 'Control/status word'], + 0x04: ['TAR', 'Transfer address'], + # 0x08: Reserved SBZ + 0x0c: ['DRW', 'Data read/write'], + 0x10: ['BD0', 'Banked data 0'], + 0x14: ['BD1', 'Banked data 1'], + 0x18: ['BD2', 'Banked data 2'], + 0x1c: ['BD3', 'Banked data 3'], + # 0x20-0xf4: Reserved SBZ + 0x800000000: ['ROM', 'Debug ROM address'], + 0xfc: ['IDR', 'Identification register'], +} + +# TODO: All start/end sample values in self.put() calls are bogus. +# TODO: Split off generic ARM/Cortex-M3 parts into another protocol decoder? + +# Bits[31:28]: Version (here: 0x3) +# JTAG-DP: 0x3, SW-DP: 0x2 +# Bits[27:12]: Part number (here: 0xba00) +# JTAG-DP: 0xba00, SW-DP: 0xba10 +# Bits[11:1]: JEDEC (JEP-106) manufacturer ID (here: 0x23b) +# Bits[11:8]: Continuation code ('ARM Limited': 0x04) +# Bits[7:1]: Identity code ('ARM Limited': 0x3b) +# Bits[0:0]: Reserved (here: 0x1) +def decode_device_id_code(bits): + id_hex = '0x%x' % int('0b' + bits, 2) + ver = '0x%x' % int('0b' + bits[-32:-28], 2) + part = '0x%x' % int('0b' + bits[-28:-12], 2) + manuf = '0x%x' % int('0b' + bits[-12:-1], 2) + res = '0x%x' % int('0b' + bits[-1], 2) + return (id_hex, ver, part, manuf, res) + +# DPACC is used to access debug port registers (CTRL/STAT, SELECT, RDBUFF). +# APACC is used to access all Access Port (AHB-AP) registers. + +# APACC/DPACC, when transferring data IN: +# Bits[34:3] = DATA[31:0]: 32bit data to transfer (write request) +# Bits[2:1] = A[3:2]: 2-bit address (debug/access port register) +# Bits[0:0] = RnW: Read request (1) or write request (0) +def data_in(instruction, bits): + data, a, rnw = bits[:-3], bits[-3:-1], bits[-1] + data_hex = '0x%x' % int('0b' + data, 2) + r = 'Read request' if (rnw == '1') else 'Write request' + # reg = dp_reg[a] if (instruction == 'DPACC') else apb_ap_reg[a] + reg = dp_reg[a] if (instruction == 'DPACC') else a # TODO + return 'New transaction: DATA: %s, A: %s, RnW: %s' % (data_hex, reg, r) + +# APACC/DPACC, when transferring data OUT: +# Bits[34:3] = DATA[31:0]: 32bit data which is read (read request) +# Bits[2:0] = ACK[2:0]: 3-bit acknowledge +def data_out(bits): + data, ack = bits[:-3], bits[-3:] + data_hex = '0x%x' % int('0b' + data, 2) + ack_meaning = ack_val.get(ack, 'Reserved') + return 'Previous transaction result: DATA: %s, ACK: %s' \ + % (data_hex, ack_meaning) + class Decoder(srd.Decoder): api_version = 1 id = 'jtag_stm32' @@ -77,11 +133,12 @@ class Decoder(srd.Decoder): optional_probes = [] options = {} annotations = [ - ['ASCII', 'TODO: description'], + ['Text', 'Human-readable text'], ] def __init__(self, **kwargs): self.state = 'IDLE' + # self.state = 'BYPASS' def start(self, metadata): # self.out_proto = self.add(srd.OUTPUT_PROTO, 'jtag_stm32') @@ -90,48 +147,44 @@ class Decoder(srd.Decoder): def report(self): pass - def handle_reg_bypass(self, bits): + def handle_reg_bypass(self, cmd, bits): # TODO - pass + self.put(self.ss, self.es, self.out_ann, [0, ['BYPASS: ' + bits]]) - def handle_reg_idcode(self, bits): + def handle_reg_idcode(self, cmd, bits): # TODO - pass - - # When transferring data IN: - # Bits[34:3] = DATA[31:0]: 32bit data to transfer (write request) - # Bits[2:1] = A[3:2]: 2-bit address of a debug port register - # Bits[0:0] = RnW: Read request (1) or write request (0) - # When transferring data OUT: - # Bits[34:3] = DATA[31:0]: 32bit data which is read (read request) - # Bits[2:0] = ACK[2:0]: 3-bit acknowledge - def handle_reg_dpacc(self, bits): - self.put(self.ss, self.es, self.out_ann, [0, ['bits: ' + bits]]) - - # Data IN - data, a, rnw = bits[:-3], bits[-4:-1], bits[-1] - r = 'Read request' if (rnw == '1') else 'Write request' - s = 'DATA: %s, A: %s, RnW: %s' % (data, ack_val[a], r) + # IDCODE is a read-only register which is always accessible. + # IR == IDCODE: The device ID code is shifted out via DR next. + self.put(self.ss, self.es, self.out_ann, + [0, ['IDCODE: %s (ver=%s, part=%s, manuf=%s, res=%s)' % \ + decode_device_id_code(bits)]]) + + def handle_reg_dpacc(self, cmd, bits): + # self.put(self.ss, self.es, self.out_ann, + # [0, ['DPACC/%s: %s' % (cmd, bits)]]) + s = data_in('DPACC', bits) if (cmd == 'DR TDI') else data_out(bits) self.put(self.ss, self.es, self.out_ann, [0, [s]]) - # Data OUT - # data, ack = bits[:-3], bits[-3:] - # ack_meaning = ack_val[ack] - # s = 'DATA: %s, ACK: %s' % (data, ack_meaning) - # self.put(self.ss, self.es, self.out_ann, [0, [s]]) - - def handle_reg_apacc(self, bits): - # TODO - pass + def handle_reg_apacc(self, cmd, bits): + # self.put(self.ss, self.es, self.out_ann, + # [0, ['APACC/%s: %s' % (cmd, bits)]]) + s = data_in('APACC', bits) if (cmd == 'DR TDI') else data_out(bits) + self.put(self.ss, self.es, self.out_ann, [0, [s]]) - def handle_reg_abort(self, bits): + def handle_reg_abort(self, cmd, bits): # Bits[31:1]: reserved. Bit[0]: DAPABORT. a = '' if (bits[0] == '1') else 'No ' s = 'DAPABORT = %s: %sDAP abort generated' % (bits[0], a) self.put(self.ss, self.es, self.out_ann, [0, [s]]) + # Warn if DAPABORT[31:1] contains non-zero bits. if (bits[:-1] != ('0' * 31)): - pass # TODO: Error + self.put(self.ss, self.es, self.out_ann, + [0, ['WARNING: DAPABORT[31:1] reserved!']]) + + def handle_reg_unknown(self, cmd, bits): + self.put(self.ss, self.es, self.out_ann, + [0, ['Unknown instruction: ' % bits]]) # TODO def decode(self, ss, es, data): # Assumption: The right-most char in the 'val' bitstring is the LSB. @@ -139,8 +192,41 @@ class Decoder(srd.Decoder): self.ss, self.es = ss, es - self.put(self.ss, self.es, self.out_ann, [0, [cmd + ' / ' + val]]) + # self.put(self.ss, self.es, self.out_ann, [0, [cmd + ' / ' + val]]) # State machine - # TODO + if self.state == 'IDLE': + # Wait until a new instruction is shifted into the IR register. + if cmd != 'IR TDI': + return + # Switch to the state named after the instruction, or 'UNKNOWN'. + # Ignore bits other than IR[3:0]. While the IR register is only + # 4 bits in size, some programs (e.g. OpenOCD) might fill in a + # few more (dummy) bits. OpenOCD makes IR at least 8 bits long. + self.state = ir.get(val[-4:], ['UNKNOWN', 0])[0] + self.put(self.ss, self.es, self.out_ann, [0, ['IR: ' + self.state]]) + elif self.state == 'BYPASS': + # Here we're interested in incoming bits (TDI). + if cmd != 'DR TDI': + return + handle_reg = getattr(self, 'handle_reg_%s' % self.state.lower()) + handle_reg(cmd, val) + self.state = 'IDLE' + elif self.state in ('IDCODE', 'ABORT', 'UNKNOWN'): + # Here we're interested in outgoing bits (TDO). + if cmd != 'DR TDO': + return + handle_reg = getattr(self, 'handle_reg_%s' % self.state.lower()) + handle_reg(cmd, val) + self.state = 'IDLE' + elif self.state in ('DPACC', 'APACC'): + # Here we're interested in incoming and outgoing bits (TDI/TDO). + if cmd not in ('DR TDI', 'DR TDO'): + return + handle_reg = getattr(self, 'handle_reg_%s' % self.state.lower()) + handle_reg(cmd, val) + if cmd == 'DR TDO': # TODO: Assumes 'DR TDI' comes before 'DR TDO' + self.state = 'IDLE' + else: + raise Exception('Invalid state: %s' % self.state)