diff options
| -rw-r--r-- | docs/develop/natmod.rst | 9 | ||||
| -rw-r--r-- | py/dynruntime.mk | 3 | ||||
| -rwxr-xr-x | tools/mpy_ld.py | 82 |
3 files changed, 89 insertions, 5 deletions
diff --git a/docs/develop/natmod.rst b/docs/develop/natmod.rst index 18678eaef..2ccd83288 100644 --- a/docs/develop/natmod.rst +++ b/docs/develop/natmod.rst @@ -81,7 +81,14 @@ Linker limitation: the native module is not linked against the symbol table of t full MicroPython firmware. Rather, it is linked against an explicit table of exported symbols found in ``mp_fun_table`` (in ``py/nativeglue.h``), that is fixed at firmware build time. It is thus not possible to simply call some arbitrary HAL/OS/RTOS/system -function, for example. +function, for example, unless that resides at a fixed address. In that case, the path +of a linkerscript containing a series of symbol names and their fixed address can be +passed to ``mpy_ld.py`` via the ``--externs`` command line argument. That way symbols +appearing in the linkerscript will take precedence over what is provided from object +files, but at the moment the object files' implementation will still reside in the +final MPY file. The linkerscript parser is limited in its capabilities, and is +currently used only for parsing the ESP8266 port ROM symbols list (see +``ports/esp8266/boards/eagle.rom.addr.v6.ld``). New symbols can be added to the end of the table and the firmware rebuilt. The symbols also need to be added to ``tools/mpy_ld.py``'s ``fun_table`` dict in the diff --git a/py/dynruntime.mk b/py/dynruntime.mk index 1ef521bd9..84c78d622 100644 --- a/py/dynruntime.mk +++ b/py/dynruntime.mk @@ -172,6 +172,9 @@ endif endif MPY_LD_FLAGS += $(addprefix -l, $(LIBGCC_PATH) $(LIBM_PATH)) endif +ifneq ($(MPY_EXTERN_SYM_FILE),) +MPY_LD_FLAGS += --externs "$(realpath $(MPY_EXTERN_SYM_FILE))" +endif CFLAGS += $(CFLAGS_EXTRA) diff --git a/tools/mpy_ld.py b/tools/mpy_ld.py index a47653f90..6518037f2 100755 --- a/tools/mpy_ld.py +++ b/tools/mpy_ld.py @@ -402,6 +402,7 @@ class LinkEnv: self.known_syms = {} # dict of symbols that are defined self.unresolved_syms = [] # list of unresolved symbols self.mpy_relocs = [] # list of relocations needed in the output .mpy file + self.externs = {} # dict of externally-defined symbols def check_arch(self, arch_name): if arch_name != self.arch.name: @@ -491,10 +492,14 @@ def populate_got(env): sym = got_entry.sym if hasattr(sym, "resolved"): sym = sym.resolved - sec = sym.section - addr = sym["st_value"] - got_entry.sec_name = sec.name - got_entry.link_addr += sec.addr + addr + if sym.name in env.externs: + got_entry.sec_name = ".external.fixed_addr" + got_entry.link_addr = env.externs[sym.name] + else: + sec = sym.section + addr = sym["st_value"] + got_entry.sec_name = sec.name + got_entry.link_addr += sec.addr + addr # Get sorted GOT, sorted by external, text, rodata, bss so relocations can be combined got_list = sorted( @@ -520,6 +525,9 @@ def populate_got(env): dest = int(got_entry.name.split("+")[1], 16) // env.arch.word_size elif got_entry.sec_name == ".external.mp_fun_table": dest = got_entry.sym.mp_fun_table_offset + elif got_entry.sec_name == ".external.fixed_addr": + # Fixed-address symbols should not be relocated. + continue elif got_entry.sec_name.startswith(".text"): dest = ".text" elif got_entry.sec_name.startswith(".rodata"): @@ -1207,6 +1215,9 @@ def link_objects(env, native_qstr_vals_len): sym.section = env.obj_table_section elif sym.name in env.known_syms: sym.resolved = env.known_syms[sym.name] + elif sym.name in env.externs: + # Fixed-address symbols do not need pre-processing. + continue else: if sym.name in fun_table: sym.section = mp_fun_table_sec @@ -1214,6 +1225,15 @@ def link_objects(env, native_qstr_vals_len): else: undef_errors.append("{}: undefined symbol: {}".format(sym.filename, sym.name)) + for sym in env.externs: + if sym in env.known_syms: + log( + LOG_LEVEL_1, + "Symbol {} is a fixed-address symbol at {:08x} and is also provided from an object file".format( + sym, env.externs[sym] + ), + ) + if undef_errors: raise LinkError("\n".join(undef_errors)) @@ -1456,6 +1476,9 @@ def do_link(args): log(LOG_LEVEL_2, "qstr vals: " + ", ".join(native_qstr_vals)) env = LinkEnv(args.arch) try: + if args.externs: + env.externs = parse_linkerscript(args.externs) + # Load object files for fn in args.files: with open(fn, "rb") as f: @@ -1484,6 +1507,50 @@ def do_link(args): sys.exit(1) +def parse_linkerscript(source): + # This extracts fixed-address symbol lists from linkerscripts, only parsing + # a small subset of all possible directives. Right now the only + # linkerscript file this is really tested against is the ESP8266's builtin + # ROM functions list ($SDK/ld/eagle.rom.addr.v6.ld). + # + # The parser should be able to handle symbol entries inside ESP-IDF's ROM + # symbol lists for the ESP32 range of MCUs as well (see *.ld files in + # $SDK/components/esp_rom/<name>/). + + symbols = {} + + LINE_REGEX = re.compile( + r'^(?P<weak>PROVIDE\()?' # optional weak marker start + r'(?P<symbol>[a-zA-Z_]\w*)' # symbol name + r'=0x(?P<address>[\da-fA-F]{1,8})*' # symbol address + r'(?(weak)\));$', # optional weak marker end and line terminator + re.ASCII, + ) + + inside_comment = False + for line in (line.strip() for line in source.readlines()): + if line.startswith('/*') and not inside_comment: + if not line.endswith('*/'): + inside_comment = True + continue + if inside_comment: + if line.endswith('*/'): + inside_comment = False + continue + if line.startswith('//'): + continue + match = LINE_REGEX.match(''.join(line.split())) + if not match: + continue + tokens = match.groupdict() + symbol = tokens['symbol'] + address = int(tokens['address'], 16) + if symbol in symbols: + raise ValueError(f"Symbol {symbol} already defined") + symbols[symbol] = address + return symbols + + def main(): import argparse @@ -1500,6 +1567,13 @@ def main(): cmd_parser.add_argument( "--output", "-o", default=None, help="output .mpy file (default to input with .o->.mpy)" ) + cmd_parser.add_argument( + "--externs", + "-e", + type=argparse.FileType("rt"), + default=None, + help="linkerscript providing fixed-address symbols to augment symbol resolution", + ) cmd_parser.add_argument("files", nargs="+", help="input files") args = cmd_parser.parse_args() |