diff options
Diffstat (limited to 'mpm/python')
| -rw-r--r-- | mpm/python/usrp_mpm/CMakeLists.txt | 6 | ||||
| -rw-r--r-- | mpm/python/usrp_mpm/tlv_eeprom.py | 143 |
2 files changed, 148 insertions, 1 deletions
diff --git a/mpm/python/usrp_mpm/CMakeLists.txt b/mpm/python/usrp_mpm/CMakeLists.txt index f1637ab03..c5b55283f 100644 --- a/mpm/python/usrp_mpm/CMakeLists.txt +++ b/mpm/python/usrp_mpm/CMakeLists.txt @@ -12,18 +12,22 @@ set(USRP_MPM_TOP_FILES ${CMAKE_CURRENT_SOURCE_DIR}/__init__.py.in ${CMAKE_CURRENT_SOURCE_DIR}/aurora_control.py ${CMAKE_CURRENT_SOURCE_DIR}/bfrfs.py + ${CMAKE_CURRENT_SOURCE_DIR}/bist.py ${CMAKE_CURRENT_SOURCE_DIR}/components.py ${CMAKE_CURRENT_SOURCE_DIR}/discovery.py ${CMAKE_CURRENT_SOURCE_DIR}/eeprom.py ${CMAKE_CURRENT_SOURCE_DIR}/e31x_legacy_eeprom.py ${CMAKE_CURRENT_SOURCE_DIR}/ethdispatch.py + ${CMAKE_CURRENT_SOURCE_DIR}/fpga_bit_to_bin.py ${CMAKE_CURRENT_SOURCE_DIR}/gpsd_iface.py ${CMAKE_CURRENT_SOURCE_DIR}/mpmlog.py ${CMAKE_CURRENT_SOURCE_DIR}/mpmtypes.py ${CMAKE_CURRENT_SOURCE_DIR}/mpmutils.py ${CMAKE_CURRENT_SOURCE_DIR}/prefs.py - ${CMAKE_CURRENT_SOURCE_DIR}/rpc_server.py ${CMAKE_CURRENT_SOURCE_DIR}/process_manager.py + ${CMAKE_CURRENT_SOURCE_DIR}/rpc_server.py + ${CMAKE_CURRENT_SOURCE_DIR}/tlv_eeprom.py + ${CMAKE_CURRENT_SOURCE_DIR}/user_eeprom.py ) list(APPEND USRP_MPM_FILES ${USRP_MPM_TOP_FILES}) add_subdirectory(chips) diff --git a/mpm/python/usrp_mpm/tlv_eeprom.py b/mpm/python/usrp_mpm/tlv_eeprom.py new file mode 100644 index 000000000..671433ffa --- /dev/null +++ b/mpm/python/usrp_mpm/tlv_eeprom.py @@ -0,0 +1,143 @@ +# +# Copyright 2019 Ettus Research, a National Instruments Brand +# +# SPDX-License-Identifier: GPL-3.0-or-later +# +""" +Tag-Length-Value (TLV) based EEPROM management code +""" + +import struct +import zlib + +class NamedStruct: + """ + Helper class for unpacking values from bytes + """ + def __init__(self, fmt, keys): + self.struct = struct.Struct(fmt) + self.keys = keys + + # ensure no duplicate keys + assert len(set(keys) - set([None])) == \ + len([x for x in keys if x is not None]) + # ensure same number of keys as elements + assert len(self.struct.unpack(bytearray(self.size))) == len(keys) + + def unpack_from(self, buf, offset=0): + """ + Unpack values from the struct, returning a dictionary mapping a field + name to a value. If the field name is None, the field is not included + in the returned dictionary. + + buf -- the buffer to unpack from + offset -- the offset within that buffer + """ + + vals = self.struct.unpack_from(buf, offset) + return {x[0]: x[1] for x in zip(self.keys, vals) if x[0] is not None} + + @property + def size(self): + """ + number of values to unpack + """ + return self.struct.size + + +def tlv_eeprom_validate(eeprom, expected_magic): + """ + Validate the contents of the EEPROM and return a tuple (header, tlv) + Header is a dictionary of the EEPROM header (magic, size, crc) + Tlv is the raw TLV data + + eeprom -- raw eeprom data + expected_magic -- magic value that's expected + """ + def crc32(data, initial=0): + initial = initial ^ 0xFFFFFFFF + crc = zlib.crc32(data, initial) + return crc ^ 0xFFFFFFFF + + size_offset = 8 + tlv_eeprom_hdr = NamedStruct('< I I I', ['magic', 'crc', 'size']) + hdr = tlv_eeprom_hdr.unpack_from(eeprom) + + if hdr['magic'] != expected_magic: + raise RuntimeError( + "Received incorrect EEPROM magic. " + "Read: {:08X} Expected: {:08X}".format( + hdr['magic'], expected_magic)) + + if hdr['size'] > (len(eeprom) - tlv_eeprom_hdr.size): + raise RuntimeError('invalid size') + + crc = crc32(eeprom[size_offset:tlv_eeprom_hdr.size+hdr['size']]) + if hdr['crc'] != crc: + raise RuntimeError( + "Received incorrect CRC. " + "Read: {:08X} Expected: {:08X}".format( + hdr['crc'], crc)) + + return hdr, eeprom[tlv_eeprom_hdr.size:tlv_eeprom_hdr.size+hdr['size']] + + +def tlv_eeprom_unpack(tlv, tagmap): + """ + Parse TLV data and return a dictionary of values found + + tlv -- raw TLV data from the EEPROM + tagmap -- dictionary mapping 8-bit tag to a NamedStruct instance + """ + + values = {} + hdr_struct = NamedStruct('< B B', ['tag', 'len']) + idx = 0 + + while idx < len(tlv): + hdr = hdr_struct.unpack_from(tlv, idx) + idx += hdr_struct.size + + if hdr['tag'] in tagmap: + val_struct = tagmap[hdr['tag']] + if hdr['len'] != val_struct.size: + raise RuntimeError( + "unexpected size: {:d}, expected: {:d}".format( + hdr['len'], tagmap[hdr['tag']])) + unpacked = val_struct.unpack_from(tlv, idx) + # prohibit clobbering existing values + assert len(set(values.keys()) & set(unpacked.keys())) == 0 + values.update(unpacked) + + idx += hdr['len'] + + return values + + +def read_eeprom( + nvmem_path, + tagmap, + expected_magic, + max_size=None +): + """ + Read the EEPROM located at nvmem_path and return a tuple (header, data) + Header is a dictionary of values unpacked from eeprom based upon tagmap + Data contains the full eeprom contents + + nvmem_path -- Path to readable file (typically something in sysfs) + tagmap -- dictionary mapping an 8-bit tag to a NamedStruct instance + expected_magic -- magic value that is expected + max_size -- Max number of bytes to read from nvmem, whole file if omitted + + Tagmap should be a dictionary mapping an 8-bit tag to a NamedStruct + instance. For each tag that's found in the eeprom, the value at that tag + will be unpacked using the associated NamedStruct; any named fields within + that struct will then be added to the returned dictionary. + """ + + max_size = max_size or -1 + with open(nvmem_path, "rb") as nvmem_file: + data = nvmem_file.read(max_size) + _, tlv = tlv_eeprom_validate(data, expected_magic) + return tlv_eeprom_unpack(tlv, tagmap), data |