Add automatic flash CRC patching to cmake

stm-firmware/crc-patcher/crc-patch-elf.py

@@ -0,0 +1,113 @@
+#!/bin/python
+
+"""
+This script patches the CRC checksums into an existing ELF file.
+
+For this, it searches the follwoing sections:
+	1) .text
+	2) .data
+	3) .ccmdata
+	4) .vectors
+
+All sections MUST be a multiple of 4 bytes long because the CRC calculation relies on whole 32 bit words.
+The sections are excrated and the CRC is calculated for each section.
+
+In the section .flashcrc, the script expects a single struct with the prototype:
+struct flash_crcs {
+	uint32_t start_magic;
+	uint32_t crc_section_text;
+	uint32_t crc_section_data;
+	uint32_t crc_section_ccm_data;
+	uint32_t crc_section_vectors;
+	uint32_t end_magic;
+};
+
+It checks, if the start magic and end magic are set to the appropriate values and then patches in the CRC values of the sections.
+The magic values checked for are: 0xA8BE53F9 and 0xFFA582FF
+"""
+from elftools.elf.elffile import ELFFile
+from elftools.elf.segments import Segment
+import elftools.elf.constants as elf_const
+import sys
+import crcmod
+import crcmod.predefined
+import struct
+
+crc_calc = crcmod.predefined.mkCrcFun('crc-32-mpeg')
+
+if len(sys.argv) < 2:
+	print("Usage:", sys.argv[0], ' <elf file>')
+	sys.exit(-1)
+
+filename=sys.argv[1]
+
+def section_calculate_crc(section):
+	data = bytearray(section.data())
+	be_data = bytearray([0 for k in range(0, len(data))])
+	# Rearrange data, because the STM controller sees it as 32 bit little endian words
+	for i in range(0, int(len(data)/4)):
+		be_data[i*4+0] = data[i*4+3]
+		be_data[i*4+1] = data[i*4+2]
+		be_data[i*4+2] = data[i*4+1]
+		be_data[i*4+3] = data[i*4+0]
+
+	return crc_calc(be_data)
+
+with open(filename, 'r+b') as f:
+	elf = ELFFile(f)
+	sections = {}
+	sections['.text'] = elf.get_section_by_name('.text')
+	sections['.data'] = elf.get_section_by_name('.data')
+	sections['.ccmdata'] = elf.get_section_by_name('.ccmdata')
+	sections['.vectors'] = elf.get_section_by_name('.vectors')
+
+	for key, sec in sections.items():
+		if sec is None:
+			print("Error! Section", key, "not found in ELF file!")
+			sys.exit(-1)
+		print('Found section', key, 'Size:',
+			  sec.data_size, 'Type:', sec['sh_type'])
+		if sec['sh_type'] != 'SHT_PROGBITS':
+			print('Error! Section must be of type SHT_PROGBITS')
+			sys.exit(-1)
+		if (sec.data_size % 4 != 0):
+			print("Section", key, "has wrong size. Must be a multiple of 4 bytes!")
+			sys.exit(-1)
+
+	text_crc = section_calculate_crc(sections['.text'])
+	print('CRC of .text section:', hex(text_crc))
+	data_crc = section_calculate_crc(sections['.data'])
+	print('CRC of .data section:', hex(data_crc))
+	ccmdata_crc = section_calculate_crc(sections['.ccmdata'])
+	print('CRC of .ccmdata section:', hex(ccmdata_crc))
+	vextors_crc = section_calculate_crc(sections['.vectors'])
+	print('CRC of .vectors section:', hex(vextors_crc))
+
+	# Check the flashcrc section
+	flashcrc_sec = elf.get_section_by_name('.flashcrc')
+	if flashcrc_sec is None:
+		print('Section for flash CRC missing!')
+		sys.exit(-1)
+	if flashcrc_sec.data_size != 6*4:
+		print("Warning!!! .flashcrc section has wrong size:",flashcrc_sec.data_size)
+
+	crc_sec_data = bytearray(flashcrc_sec.data())
+	magic1 = struct.unpack('<I'*1, bytes(crc_sec_data[0:4]))[0]
+	magic2 = struct.unpack('<I'*1, bytes(crc_sec_data[-4:]))[0]
+	print("CRC section magic values:", hex(magic1), hex(magic2))
+	if magic1 != 0xA8BE53F9 or magic2 != 0xFFA582FF:
+		print("Wrong magics in CRC section. Data misalignment?")
+		sys.exit(-2)
+
+	crc_sec_offset = flashcrc_sec['sh_offset']
+	print('CRC section ELF file offset:', hex(crc_sec_offset))
+	
+	crc_sec_data[4:8] = struct.pack('<I',text_crc)
+	crc_sec_data[8:12] = struct.pack('<I',data_crc)
+	crc_sec_data[12:16] = struct.pack('<I',ccmdata_crc)
+	crc_sec_data[16:20] = struct.pack('<I',vextors_crc)
+	f.seek(crc_sec_offset)
+	f.write(crc_sec_data)
+	print('CRCs patched successfully')
+
+	

stm-firmware/crc-patcher/requirements.txt

@@ -0,0 +1,2 @@
+crcmod==1.7
+pyelftools==0.27