remove printf references, add bootloader script, merge hex files

targets/stm32l442/merge_hex.py

@@ -0,0 +1,28 @@
+# Merges bootloader and application into 1 file for ST Solo
+#
+# Patches settings in flash so bootloader will boot application.
+
+from intelhex import IntelHex
+import sys
+
+if len(sys.argv) < 3:
+    print('usage: %s <file1.hex> <file2.hex> [...] <output.hex>')
+    sys.exit(1)
+
+def flash_addr(num):
+    return 0x08000000 + num * 2048
+
+PAGES = 128
+APPLICATION_END_PAGE = PAGES - 19
+AUTH_WORD_ADDR       = (flash_addr(APPLICATION_END_PAGE)-8)
+
+first = IntelHex(sys.argv[1])
+for i in range(2, len(sys.argv)-1):
+    first.merge(IntelHex( sys.argv[i] ), overlap = 'replace')
+
+first[AUTH_WORD_ADDR]   = 4
+first[AUTH_WORD_ADDR+1] = 5
+first[AUTH_WORD_ADDR+2] = 6
+first[AUTH_WORD_ADDR+3] = 7
+
+first.tofile(sys.argv[len(sys.argv)-1], format='hex')