various small bugfixes

riscemu/CPU.py

@@ -88,6 +88,8 @@ class UserModeCPU(CPU):
         while not self.halted:
             self.step(verbose)
 
+        print(FMT_CPU + "[CPU] Program exited with code {}".format(self.exit_code) + FMT_NONE)
+
     def setup_stack(self, stack_size=1024 * 4) -> bool:
         """
         Create program stack and populate stack pointer

riscemu/MMU.py

@@ -234,10 +234,10 @@ class MMU:
             "\n\t".join(repr(x) for x in self.programs)
         )
 
-    def context_for(self, addr: T_AbsoluteAddress) -> Optional[InstructionContext]:
+    def context_for(self, addr: T_AbsoluteAddress) -> InstructionContext:
         sec = self.get_sec_containing(addr)
 
         if sec is not None:
             return sec.context
 
-        return None
+        return InstructionContext()

riscemu/__main__.py

@@ -5,6 +5,7 @@ SPDX-License-Identifier: MIT
 
 This file holds the logic for starting the emulator from the CLI
 """
+from riscemu import RiscemuBaseException
 from riscemu.CPU import UserModeCPU
 
 if __name__ == '__main__':
@@ -114,6 +115,7 @@ if __name__ == '__main__':
 
         # launch the last loaded program
         cpu.launch(cpu.mmu.programs[-1], verbose=cfg.verbosity > 1)
+
     except RiscemuBaseException as e:
         print("Error: {}".format(e.message()))
         e.print_stacktrace()

riscemu/assembler.py

@@ -175,8 +175,9 @@ class AssemblerDirectives:
 
         if content is None:
             content = bytearray(size)
-        if isinstance(context, int):
+        if isinstance(content, int):
             content = int_to_bytes(content, size, unsigned)
+
         context.section.data += content
 
     @classmethod

riscemu/debug.py

@@ -11,6 +11,7 @@ from .helpers import *
 if typing.TYPE_CHECKING:
     from riscemu import CPU, Registers
 
+HIST_FILE = os.path.join(os.path.expanduser('~'), '.riscemu_history')
 
 
 def launch_debug_session(cpu: 'CPU', prompt=""):
@@ -78,8 +79,8 @@ def launch_debug_session(cpu: 'CPU', prompt=""):
     # add tab completion
     readline.set_completer(rlcompleter.Completer(sess_vars).complete)
     readline.parse_and_bind("tab: complete")
-    if os.path.exists('~/.riscemu_history'):
-        readline.read_history_file('~/.riscemu_history')
+    if os.path.exists(HIST_FILE):
+        readline.read_history_file(HIST_FILE)
 
     relaunch_debugger = False
 
@@ -90,5 +91,5 @@ def launch_debug_session(cpu: 'CPU', prompt=""):
         )
     finally:
         cpu.debugger_active = False
-        readline.write_history_file('~/.riscemu_history')
+        readline.write_history_file(HIST_FILE)
 

riscemu/helpers.py

@@ -46,7 +46,7 @@ def int_from_bytes(bytes, unsigned=False) -> int:
     if unsigned:
         return num
 
-    return to_signed(num)
+    return to_signed(num, len(bytes))
 
 
 def to_unsigned(num: int, bytes=4) -> int:

riscemu/parser.py

@@ -31,7 +31,7 @@ def parse_label(token: Token, args: Tuple[str], context: ParseContext):
     else:
         if name in context.context.labels:
             print(FMT_PARSE + 'Warn: Symbol {} defined twice!'.format(name))
-        context.context.labels[name] = context.section.current_address()
+        context.add_label(name, context.section.current_address(), is_relative=True)
 
 
 PARSERS: Dict[TokenType, Callable[[Token, Tuple[str], ParseContext], None]] = {
@@ -53,7 +53,6 @@ def parse_tokens(name: str, tokens_iter: Iterable[Token]) -> Program:
     for token, args in composite_tokenizer(Peekable[Token](tokens_iter)):
         if token.type not in PARSERS:
             raise ParseException("Unexpected token type: {}, {}".format(token, args))
-        print('{}: {}'.format(token, args))
         PARSERS[token.type](token, args, context)
 
     return context.finalize()
@@ -74,8 +73,6 @@ def composite_tokenizer(tokens_iter: Iterable[Token]) -> Iterable[Tuple[Token, T
         token = next(tokens)
         if token.type in (TokenType.PSEUDO_OP, TokenType.LABEL, TokenType.INSTRUCTION_NAME):
             yield token, tuple(take_arguments(tokens))
-        else:
-            print("skipped {}".format(token))
 
 
 def take_arguments(tokens: Peekable[Token]) -> Iterable[str]:

riscemu/priv/PrivMMU.py

@@ -24,7 +24,7 @@ class PrivMMU(MMU):
 
         # calc start end end of "free" space
         prev_sec_end = 0 if sec_before is None else sec_before.end
-        next_sec_start = 0x7FFFFFFF if sec_after is None else sec_before.base
+        next_sec_start = 0x7FFFFFFF if sec_after is None else sec_after.base
 
         # start at the end of the prev section, or current address - 0xFFFF (aligned to 16 byte boundary)
         start = max(prev_sec_end, align_addr(addr - 0xFFFF, 16))

riscemu/types.py

@@ -258,11 +258,10 @@ class Program:
 
     @property
     def entrypoint(self):
-        base = 0 if self.base is None else self.base
         if '_start' in self.context.labels:
-            return base + self.context.labels.get('_start')
+            return self.context.labels.get('_start')
         if 'main' in self.context.labels:
-            return base + self.context.labels.get('main')
+            return self.context.labels.get('main')
         for sec in self.sections:
             if get_section_base_name(sec.name) == '.text' and sec.flags.executable:
                 return sec.base